Troubleshooting / Parker SSD trips

Parker SSD Drive Trip Codes

The trip messages of Parker drives from the SSD Drives range, the 590+ DC drive, the AC690+ and the AC10: what each one means, the likely causes, the first checks with the parameters to look at, and how to log it so it stops coming back.

How trips show

590+ DC drive: when a trip happens the power stage switches off at once, the motor coasts to a stop and the trip latches. The HEALTH LED (on the drive and on the 6901 keypad) goes out, terminal B6 (Healthy) goes low and the keypad shows the trip message, for example HEATSINK TRIP. Press E to acknowledge the message.

The ALARM STATUS menu shows LAST ALARM (tag 528), HEALTH WORD (tag 115, every active alarm added together as a 4-digit hex value) and HEALTH STORE (tag 116, the first alarm), and the ALARM HISTORY block keeps the last 10 alarms as hex codes.

To reset, remove the cause first (a hot heatsink must cool down), then remove and re-apply the Start/Run signal (terminal C3 or C4, or STOP then RUN on the keypad), or switch the auxiliary supply off and on. 690+ AC drive: the HEALTH LED flashes, the keypad shows * * * TRIPPED * * * on the top line and the trip name on the bottom line, and the TRIPPED output of SEQUENCING LOGIC goes TRUE. FIRST TRIP (tag 6) names the first trip, ACTIVE TRIPS (tag 4) and ACTIVE TRIPS+ (tag 740) show active trips as hex, WARNINGS (tag 5) shows conditions close to tripping, and TRIPS HISTORY (tags 500 to 509) keeps the last 10 trips through a power loss.

Reset with the STOP key, the remote trip reset input (REM TRIP RESET, tag 282) or, if TRIP RST BY RUN (tag 290) is TRUE, a new run command. Success shows as a steady HEALTH LED. AC10: the 4-digit display shows the fault code (for example OC, OE or OH). Press the O (stop) key to reset, or set F214 for automatic reset and restart.

Safety first.
Isolate every incoming supply before working on the drive, and remember a drive can have more than one supply connection.

After switching off, wait at least 10 minutes on a 590+ DC drive, at least 5 minutes on a 690+ frame B to F, and at least 5 minutes on an AC10 (20 minutes above 30 kW) for the capacitors to discharge below 50 V. Then use a CAT III or higher meter rated to 1000 V DC and AC rms to confirm less than 50 V between all power terminals and to earth.

Dangerous voltage can stay on the motor, supply, DC bus and brake terminals while the motor is stopped, and after a fault the stored energy may take longer to discharge than stated. Sources: 590+ manual HA466461U004 Issue 6, Product Warnings page Cont. 4; 690+ manual HA465492U006 Issue 2, Hazards page. AC10 manual HA502320U001 Issue 7, page 1-2.

Follow lockout/tagout and your site's safe-work procedures, and check the manual for your exact model before you act.

Quick lookup

Trips stop the drive and the machine it runs, so in OEE they are availability losses.

Type a trip or a word (overcurrent, heatsink, field, speed feedback) to filter the list. Click a trip for its causes and first checks.

82 codes

CodeDriveName
OVERCURRENT690+Motor current too high (FIRST TRIP value 3, ACTIVE TRIPS mask 0x0004)
OVERVOLTAGE690+DC link voltage too high (FIRST TRIP value 1, ACTIVE TRIPS mask 0x0001)
FIELD FAIL590+Motor field failure (FIELD FAILED, hex 0x0100)
HEATSINK TRIP590+Drive heatsink over temperature (hex 0x0008)
HEATSINK690+Drive heatsink too hot (FIRST TRIP value 4, ACTIVE TRIPS mask 0x0008)
OVER SPEED590+Motor overspeed (written OVERSPEED in the trip table, hex 0x0001)
MISSING PULSE590+Missing pulse in the armature current (hex 0x0002)
SPEED FEEDBACK590+Speed feedback alarm (SPD FEEDBACK, hex 0x0040)
3 PHASE FAILED590+3-phase supply failure (written 3-PHASE FAILED in the trip table, hex 0x0200)
OVER I TRIP590+Armature overcurrent (hex 0x2000)
UNDERVOLTAGE690+DC link voltage too low (FIRST TRIP value 2, ACTIVE TRIPS mask 0x0002)
EXTERNAL TRIP690+External trip from the control terminals (FIRST TRIP value 5, ACTIVE TRIPS mask 0x0010)
EXTERNAL TRIP590+Customer external trip (LAST ALARM 0xF005)
THERMISTOR590+Motor over temperature (hex 0x0010)
MOTOR OVERTEMP690+Motor over temperature (FIRST TRIP value 17, ACTIVE TRIPS+ mask 0x0001)
INPUT 1 BREAK690+Analog input 1 signal break (FIRST TRIP value 6, ACTIVE TRIPS mask 0x0020)
DESAT (OVER I)690+Instantaneous overcurrent (FIRST TRIP value 24, ACTIVE TRIPS+ mask 0x0080)
MOTOR STALLED690+Motor stalled (FIRST TRIP value 8, ACTIVE TRIPS mask 0x0080)
INVERSE TIME690+Inverse time overload (FIRST TRIP value 9, ACTIVE TRIPS mask 0x0100)
FIELD OVER I590+Field overcurrent (hex 0x0004)
OVER VOLTS (VA)590+Armature overvoltage (hex 0x0020)
ENCODER FAILED590+Encoder speed feedback lost (hex 0x0080)
PHASE LOCK590+Supply frequency out of range (hex 0x0400)
PHASE FAIL690+Supply phase missing (FIRST TRIP value 22, ACTIVE TRIPS+ mask 0x0020)
VDC RIPPLE690+DC link ripple too high (FIRST TRIP value 25, ACTIVE TRIPS+ mask 0x0100)
LOST COMMS690+Remote communications lost (FIRST TRIP value 13, ACTIVE TRIPS mask 0x1000)
COMMS TIMEOUT590+Remote comms timeout (LAST ALARM 0xF010)
COMMS FAULT CODE x590+Keypad communication fault
OP STATION690+Keypad disconnected (FIRST TRIP value 12, ACTIVE TRIPS mask 0x0800)
NO OP STATION590+Keypad disconnected (NO OP-STATION, LAST ALARM 0xF400)
STALL TRIP590+Motor stall (hex 0x1000)
ACCTS FAILED590+AC current transformer failure (hex 0x8000)
AUTOTUNE ERROR590+Autotune failed (LAST ALARM 0xF001)
AUTOTUNE ABORTED590+Autotune aborted (written AUTOTUNE ABORT in the trip table, LAST ALARM 0xF002)
CONTACTOR DELAY590+Contactor failed to close (LAST ALARM 0xF004)
CONTACTOR FBK690+Contactor feedback missing (FIRST TRIP value 14, ACTIVE TRIPS mask 0x2000)
SPEED FEEDBACK690+Speed feedback error (FIRST TRIP value 15, ACTIVE TRIPS mask 0x4000)
OVERSPEED690+Motor overspeed (FIRST TRIP value 27, ACTIVE TRIPS+ mask 0x0400)
BRAKE RESISTOR690+Brake resistor overload (FIRST TRIP value 10, ACTIVE TRIPS mask 0x0200)
BRAKE SWITCH690+Brake switch overload (FIRST TRIP value 11, ACTIVE TRIPS mask 0x0400)
BRAKE SHORT CCT690+Brake resistor overcurrent (FIRST TRIP value 26, ACTIVE TRIPS+ mask 0x0200)
CURRENT LIMIT690+Current limit trip (FIRST TRIP value 18, ACTIVE TRIPS+ mask 0x0002)
LOW SPEED OVER I690+Overcurrent at zero speed (FIRST TRIP value 21, ACTIVE TRIPS+ mask 0x0010)
INPUT 2 BREAK690+Analog input 2 signal break (FIRST TRIP value 7, ACTIVE TRIPS mask 0x0040)
ANALOG INPUT ERR690+Analog input error (FIRST TRIP value 28, ACTIVE TRIPS+ mask 0x0800)
AMBIENT TEMP690+Drive internal ambient too hot (FIRST TRIP value 16, ACTIVE TRIPS mask 0x8000)
24V FAILURE690+24 V customer supply low (FIRST TRIP value 20, ACTIVE TRIPS+ mask 0x0008)
ENCODER 1 FAULT690+Encoder option error input (FIRST TRIP value 23, ACTIVE TRIPS+ mask 0x0040)
5703 RCV ERROR590+5703 receive error (hex 0x0800)
CALIBRATION FAIL590+Signal calibration fault (CALIBRATION, LAST ALARM 0xF300)
REMOTE TRIP590+Remote trip from comms (LAST ALARM 0xF006)
ENABLE LOW590+Enable input low in local mode (LAST ALARM 0xF007)
AUX SUPPLY590+Auxiliary supply problem (LAST ALARM 0xFF03)
CONFIG ENABLED590+Start requested in configuration mode (LAST ALARM 0xF200)
SEQ PRE READY590+Power chassis coding missing (LAST ALARM 0xF003)
SEQUENCING590+Internal sequencing error (LAST ALARM 0xF009)
CRITICAL ERROR590+Critical error (shown as CRITICAL ERROR xxxx::xxxxxxxx)
CHECKSUM FAIL590+, 690+Non-volatile memory checksum failure (590+: (EEPROM) CHECKSUM FAIL; 690+: * CHECKSUM FAIL *)
OTHER690+Other trip active (FIRST TRIP value 32, ACTIVE TRIPS+ mask 0x8000)
STACK TRIP690+Power stack trip (FIRST TRIP value 41)
POWER LOSS STOP690+Power loss stop completed (FIRST TRIP value 43)
MAX SPEED LOW690+Autotune error: maximum speed too low (FIRST TRIP value 33)
NOT AT SPEED690+Autotune error: required speed not reached (FIRST TRIP value 35)
MAG CURRENT FAIL690+Autotune error: magnetizing current not found (FIRST TRIP value 36)
NEGATIVE SLIP F690+Autotune error: negative slip frequency (FIRST TRIP value 37)
TR TOO LARGE690+Autotune error: rotor time constant too large (FIRST TRIP value 38)
TR TOO SMALL690+Autotune error: rotor time constant too small (FIRST TRIP value 39)
MAX RPM DATA ERR690+Autotune data does not cover the maximum speed (FIRST TRIP value 40)
OC/OC2AC10Overcurrent (F708 trip type 2 for OC, 67 for OC2; OC2 only on models above 22 kW)
OEAC10DC over-voltage (O.E., F708 trip type 3)
OHAC10Heatsink overheat (O.H., F708 trip type 7)
LUAC10Under-voltage (L.U., F708 trip type 6)
OL1AC10Inverter overload (O.L1, F708 trip type 5)
OL2AC10Motor overload (O.L2, F708 trip type 8)
PF1AC10Input phase loss (P.F1., F708 trip type 4)
PF0AC10Output phase loss (F708 trip type 17)
OC1AC10Overcurrent 1 (F708 trip type 16)
GPAC10Ground fault
AErrAC10Analog input disconnected (F708 trip type 18)
CEAC10Communication timeout (F708 trip type 45)
ESPAC10External coast stop (external malfunction, F708 trip type 11)
Err4AC10Current sampling fault (current zero excursion, F708 trip type 15)

Each code: causes and first checks

OVERCURRENT: Motor current too high (FIRST TRIP value 3, ACTIVE TRIPS mask 0x0004)

Hits OEE: Availability

What it means: The motor is drawing more current from the drive than it can deliver, so the drive has tripped and the motor coasts to a stop.[2][3]

Likely causes

  • Accelerating a large inertia load too quickly
  • Decelerating a large inertia load too quickly
  • Shock load on the motor
  • Short circuit between motor phases, or from a phase to earth
  • Motor cables too long, or too many motors in parallel on one drive
  • FIXED BOOST or AUTO BOOST set too high

First checks, in this order

  1. Lengthen ACCEL TIME (tag 258) and DECEL TIME (tag 259) in the REFERENCE RAMP block.
  2. Look for a jam or shock load in the machine.
  3. With power isolated, check the motor and motor cable for phase to phase and phase to earth faults.
  4. Check the total motor cable length and how many motors run from the drive.
  5. Reduce FIXED BOOST (tag 107) and AUTO BOOST (tag 108) in the FLUXING menu.
  6. This trip cannot be disabled, but it can be included in the AUTO RESTART triggers.

OVERVOLTAGE: DC link voltage too high (FIRST TRIP value 1, ACTIVE TRIPS mask 0x0001)

Hits OEE: Availability

What it means: The internal DC link voltage of the drive is too high, usually because the motor is pushing energy back into the drive while it slows down.[2][3]

Likely causes

  • Supply voltage too high
  • Trying to decelerate a large inertia load too quickly
  • Brake resistor open circuit

First checks, in this order

  1. Measure the supply voltage against the drive rating.
  2. Increase DECEL TIME (tag 259).
  3. Check the brake resistor and its wiring for an open circuit.
  4. If a brake resistor is fitted, check that DYNAMIC BRAKING ENABLE (tag 80) is TRUE.
  5. On high inertia loads without a resistor, consider fitting a dynamic braking resistor.

FIELD FAIL: Motor field failure (FIELD FAILED, hex 0x0100)

Hits OEE: Availability

What it means: The motor field current is too low: under 6% of rated current in current control mode, or under 50 mA in voltage control mode. The drive trips after 1 second.[1]

Likely causes

  • Open circuit motor field winding or connection
  • Faulty field controller
  • Onboard field regulator fed line to neutral instead of line to line at FL1 and FL2
  • 3-phase supply missing (the drive needs it to synchronise)
  • Permanent magnet motor with the field still enabled

First checks, in this order

  1. Check the field connections and measure the field winding resistance.
  2. Check that FL1 and FL2 carry line to line voltage (L1 into FL1, L2 into FL2).
  3. Confirm the 3-phase supply is present at the drive.
  4. For a motor that needs no field supply, such as a permanent magnet motor, set FIELD ENABLE (tag 170) to DISABLED.
  5. The alarm can be inhibited with FIELD FAIL (tag 19) in the ALARMS menu, only where the application allows it.

HEATSINK TRIP: Drive heatsink over temperature (hex 0x0008)

Hits OEE: Availability

What it means: The drive heatsink temperature is too high. The trip delay is 0.5 seconds, and the stack must cool down before the drive will restart.[1]

Likely causes

  • Ambient air temperature too high
  • Poor ventilation or too little spacing between drives
  • Fan failure, blown fan fuse on the power board, or fan turning the wrong way (bridge ratings above 70 A)
  • Blocked ventilation slots or clogged air filters
  • Armature current too high for the drive current calibration

First checks, in this order

  1. Check the ambient temperature and cabinet ventilation.
  2. Check that the fan runs and turns the right way, and check the fan fuse on the power board.
  3. Clean the ventilation slots and air filters.
  4. Compare the motor nameplate armature current with the drive current calibration.
  5. Frame 4 and 5: the power board LEDs FLD HS OT (field) and ARM HS OT (armature) show which heatsink is hot.
  6. Frame 6 and H: an unlit thermostat LED (field, or L1, L2, L3 stack) shows the hot heatsink. On Frame 6 a stalled fan shows as an unlit fan LED; use the fan fail override switch with the drive stopped to find it.

HEATSINK: Drive heatsink too hot (FIRST TRIP value 4, ACTIVE TRIPS mask 0x0008)

Hits OEE: Availability

What it means: The drive heatsink temperature is too high. The trip will not reset until the heatsink has cooled below the trip level.[2][3]

Likely causes

  • Ambient air temperature too high
  • Poor ventilation or too little spacing between drives
  • Cooling fan blocked or not running

First checks, in this order

  1. Check the ambient temperature around the drive.
  2. Check the spacing and air flow around the drive and the cabinet filters.
  3. Check that the cooling fan runs and the heatsink is clean.
  4. Let the drive cool before resetting. Note the keypad example in the manual shows this trip as HEATSINK TEMP.

OVER SPEED: Motor overspeed (written OVERSPEED in the trip table, hex 0x0001)

Hits OEE: Availability

What it means: Speed feedback has gone above 125% of rated speed. The trip delay is 50 ms, and the alarm only works with encoder or armature voltage feedback selected.[1]

Likely causes

  • Badly adjusted speed loop
  • Speed feedback scaling not matched to the motor

First checks, in this order

  1. Retune the speed loop gains.
  2. Check OVER SPEED LEVEL in the CALIBRATION menu.
  3. Check SPEED FBK SELECT (tag 47) and the speed feedback calibration.

MISSING PULSE: Missing pulse in the armature current (hex 0x0002)

Hits OEE: Availability

What it means: One pulse of the 6-pulse armature current waveform is missing. It only works when the load is above 1.5 times the DISCONTINUOUS value, the delay is 60 seconds, and it is meant to catch firing circuit connector problems while motoring.[1]

Likely causes

  • Firing (gate) plug failure
  • Connection failure in the firing circuit
  • A thyristor not conducting

First checks, in this order

  1. Check the thyristor firing plugs and leads are fully seated.
  2. Check the firing circuit connections.
  3. Check DISCONTINUOUS (tag 137) matches the value found by autotune.
  4. This trip does not protect the drive if a thyristor fails during regeneration; Parker recommends fusing the armature circuit on regenerative drives.

SPEED FEEDBACK: Speed feedback alarm (SPD FEEDBACK, hex 0x0040)

Hits OEE: Availability

What it means: The difference between speed feedback and armature voltage feedback is bigger than SPDFBK ALM LEVEL, or, with field weakening enabled, speed feedback is under 10% in the field weakening region. Delay 0.125 seconds.[1]

Likely causes

  • Analog tacho feedback polarity wrong at terminals G3 and G4
  • ENCODER SIGN polarity wrong
  • Broken feedback wiring, including fibre optics
  • Armature voltage calibration not reduced when running at reduced field current
  • Tachogenerator failure
  • Tachogenerator coupling failure

First checks, in this order

  1. Check tacho wiring and polarity at G3 and G4.
  2. Check ENCODER SIGN (tag 49).
  3. Check the feedback cable, connectors and any fibre optic link.
  4. Check the tacho and its coupling to the motor shaft.
  5. Check SPDFBK ALM LEVEL (tag 180). SPEED FBK STATE (tag 472) shows the alarm state even while the alarm is inhibited with SPEED FBK ALARM (tag 81).

3 PHASE FAILED: 3-phase supply failure (written 3-PHASE FAILED in the trip table, hex 0x0200)

Hits OEE: Availability

What it means: The 3-phase supply has failed completely or a phase is missing.[1]

Likely causes

  • Total loss of supply or a missing phase
  • Blown high speed thyristor stack fuses
  • Blown power chassis coding fuses
  • Wrong supply voltage for the drive
  • Frame 5: different phase sequence on the two parallel stacks

First checks, in this order

  1. Measure all three phases at the drive.
  2. Check the high speed thyristor stack fuses and the power chassis coding fuses.
  3. Compare the mains voltage with the drive Product Code.
  4. Frame 4 and 5: check the PHASE LOSS LED; Frame 5: check PH ROT FLT (phase rotation) on the Parallel Expansion Board.
  5. Frame 6 and H: an unlit THYRISTOR FUSES LED points to a blown thyristor fuse.

OVER I TRIP: Armature overcurrent (hex 0x2000)

Hits OEE: Availability

What it means: Current feedback has gone above 280% of rated current. Short peaks are allowed: 300% for up to 15 ms or 325% for up to 6.6 ms.[1]

Likely causes

  • Motor armature winding failure
  • Badly tuned current loop
  • Faulty drive

First checks, in this order

  1. With the drive disconnected, check the motor armature insulation resistance.
  2. Check the current loop tuning; run the armature autotune again.
  3. If the trip stays with a healthy motor, contact Parker.

UNDERVOLTAGE: DC link voltage too low (FIRST TRIP value 2, ACTIVE TRIPS mask 0x0002)

Hits OEE: Availability

What it means: The internal DC link voltage of the drive is too low.[2][3]

Likely causes

  • Supply voltage too low
  • Supply lost
  • A supply phase missing

First checks, in this order

  1. Measure all three supply phases at the drive terminals.
  2. Check the supply fuses and contactor.
  3. Look for supply dips when other large loads start.
  4. This trip cannot be disabled, but it can be included in the AUTO RESTART triggers.

EXTERNAL TRIP: External trip from the control terminals (FIRST TRIP value 5, ACTIVE TRIPS mask 0x0010)

Hits OEE: Availability

What it means: A user trip from the control terminals: +24 V is missing on the external trip input (terminal 19 in Macro 1, digital input 8).[2][3]

Likely causes

  • External interlock or safety device open
  • Broken wire to the external trip input
  • Link missing where no external device is fitted

First checks, in this order

  1. Measure for +24 V on the external trip input (terminal 19 in Macro 1).
  2. Check every device wired in series with that input.
  3. Check EXT TRIP MODE (tag 233): TRIP trips the drive, COAST only coasts it to a stop.
  4. EXTERNAL TRIP (tag 234) in the I/O TRIPS block reads TRUE when 0 V is on the terminal. This trip cannot be disabled.

EXTERNAL TRIP: Customer external trip (LAST ALARM 0xF005)

Hits OEE: Availability

What it means: The customer alarm input between C1 and C2 is open or high impedance. Delay 0.2 seconds.[1]

Likely causes

  • External device not wired to the drive
  • External device open circuit
  • Link between C1 and C2 missing

First checks, in this order

  1. Check the wiring between C1 and C2.
  2. Check the external device, for example a motor thermostat or blower interlock.
  3. If no customer device is fitted, link C1 to C2.

THERMISTOR: Motor over temperature (hex 0x0010)

Hits OEE: Availability

What it means: The motor temperature is too high. Delay 5 seconds, and the motor must cool before the drive will restart.[1]

Likely causes

  • Inadequate motor ventilation
  • Blower failure, blower turning the wrong way, or clogged air filters
  • Armature current too high for the drive current calibration

First checks, in this order

  1. Check the motor blower runs, turns the right way and its filters are clean.
  2. Compare the motor nameplate armature current with the drive current calibration.
  3. Check the thermistor wiring to the drive.
  4. THERMISTOR STATE (tag 337) shows TRUE while the thermistor input is active.

MOTOR OVERTEMP: Motor over temperature (FIRST TRIP value 17, ACTIVE TRIPS+ mask 0x0001)

Hits OEE: Availability

What it means: The motor thermistor input reports that the motor is too hot.[2][3]

Likely causes

  • Excessive load
  • Motor voltage rating set wrong
  • FIXED BOOST or AUTO BOOST set too high
  • Long running at low speed without forced cooling
  • INVERT THERMIST set wrong
  • Break in the motor thermistor connection

First checks, in this order

  1. Check the motor load and cooling, especially at low speed.
  2. Check the motor voltage setting against the nameplate.
  3. Check INVERT THERMIST (tag 760) in the I/O TRIPS menu; FALSE is normally closed, low impedance.
  4. Check the thermistor wiring. THERMISTOR (tag 1155) shows the input state.
  5. Reduce FIXED BOOST (tag 107) and AUTO BOOST (tag 108) if set high.

INPUT 1 BREAK: Analog input 1 signal break (FIRST TRIP value 6, ACTIVE TRIPS mask 0x0020)

Hits OEE: Availability

What it means: A signal break has been detected on analog input 1 (terminal 1), typically a 4 to 20 mA loop that has dropped out.[2][3]

Likely causes

  • Analog input set up wrongly for 4 to 20 mA
  • Break in the external control wiring
  • Transmitter or signal source failed

First checks, in this order

  1. Measure the signal at terminal 1; a 4 to 20 mA loop should never read below 4 mA.
  2. Check the ANALOG INPUT 1 type setting matches the signal.
  3. Check the wiring and the transmitter.
  4. INPUT 1 BREAK (tag 235) in I/O TRIPS is fed from the ANALOG INPUT 1 BREAK output. The trip can be disabled in DISABLED TRIPS (tag 231) if the application allows it.

DESAT (OVER I): Instantaneous overcurrent (FIRST TRIP value 24, ACTIVE TRIPS+ mask 0x0080)

Hits OEE: Availability

What it means: An instantaneous overcurrent was detected in the output stage. Parker points to the same causes as OVERCURRENT.[2][3]

Likely causes

  • Short circuit between motor phases or from a phase to earth
  • Very fast acceleration or deceleration of a large inertia
  • Shock load on the motor
  • Motor cables too long or too many motors in parallel
  • Boost set too high

First checks, in this order

  1. With power isolated, test the motor and cable insulation phase to phase and phase to earth.
  2. Lengthen ACCEL TIME (tag 258) and DECEL TIME (tag 259).
  3. Reduce FIXED BOOST (tag 107) and AUTO BOOST (tag 108).
  4. If it trips with the motor cables disconnected, the power stage may be faulty: contact Parker.

MOTOR STALLED: Motor stalled (FIRST TRIP value 8, ACTIVE TRIPS mask 0x0080)

Hits OEE: Availability

What it means: The motor has stalled: the load stayed above the active torque limit (or current limit) for longer than STALL TIME.[2][3]

Likely causes

  • Motor load too great or machine jammed
  • Current limit set too low
  • Stall trip time set too short
  • FIXED BOOST or AUTO BOOST set too high

First checks, in this order

  1. Check the machine for a jam or brake that has not released.
  2. Check CURRENT LIMIT (tag 365).
  3. Check STALL TIME (tag 241, default 480 s) and STALL LIMIT TYPE (tag 1208, TORQUE or CURRENT) in the STALL TRIP block.
  4. Reduce FIXED BOOST (tag 107) and AUTO BOOST (tag 108).

INVERSE TIME: Inverse time overload (FIRST TRIP value 9, ACTIVE TRIPS mask 0x0100)

Hits OEE: Availability

What it means: The inverse time current limit is active because the motor has been overloaded for too long: above 150% for 60 s in constant torque duty, or above 110% for 60 s in quadratic (fan and pump) duty.[2][3]

Likely causes

  • Motor loading too great
  • FIXED BOOST or AUTO BOOST set too high
  • Constant or quadratic duty selection not matched to the load

First checks, in this order

  1. Check the motor load against the drive and motor rating.
  2. Check the constant or quadratic torque selection.
  3. Check AIMING POINT (tag 1148, default 105%) and DELAY (tag 1149, default 60 s) in the INVERSE TIME block; IT LIMITING (tag 1152) shows when it is active.
  4. Reduce FIXED BOOST (tag 107) and AUTO BOOST (tag 108).
  5. The DISABLED TRIPS default shown in the manual (0x0700) includes this trip's mask, so check DISABLED TRIPS (tag 231) if it appears unexpectedly.

FIELD OVER I: Field overcurrent (hex 0x0004)

Hits OEE: Availability

What it means: Motor field current has gone above 120% of the calibrated value. Delay 10 seconds, and it only works in field current control mode.[1]

Likely causes

  • External field supply connected with the wrong supply phases
  • FIELD CURRENT setting not matched to the motor
  • Field current loop badly tuned

First checks, in this order

  1. Check the phases feeding the external field supply.
  2. Check FIELD CURRENT (tag 524) against the motor nameplate, then recalibrate the control board.
  3. Run the field autotune to tune the field current loop.

OVER VOLTS (VA): Armature overvoltage (hex 0x0020)

Hits OEE: Availability

What it means: Motor armature voltage has gone above 120% of rated volts. Delay 1 second.[1]

Likely causes

  • Loose armature connection
  • Badly adjusted field voltage setting
  • Badly adjusted field current loop
  • Badly adjusted field weakening back EMF loop
  • Badly adjusted speed loop

First checks, in this order

  1. Check and tighten the armature connections at drive and motor.
  2. Check NOM MOTOR VOLTS (tag 521) and ARMATURE V CAL. (tag 20).
  3. Check the field voltage and field current settings, and the field weakening settings if used.
  4. Retune the speed loop.

ENCODER FAILED: Encoder speed feedback lost (hex 0x0080)

Hits OEE: Availability

What it means: The drive has no speed feedback signal from the encoder.[1]

Likely causes

  • SPEED FBK SELECT set to ENCODER but no encoder option board fitted
  • Damaged fibre optic cable, bend radius too tight or run too long (Microtach)
  • Faulty cable or connections on a wired encoder

First checks, in this order

  1. Check SPEED FBK SELECT (tag 47) and that the encoder option board is fitted.
  2. Check the fibre optic cable for damage, bend radius and length.
  3. Check the encoder cable and connections.
  4. ENCODER ALARM (tag 92) can inhibit this alarm.

PHASE LOCK: Supply frequency out of range (hex 0x0400)

Hits OEE: Availability

What it means: The supply frequency is outside the 45 to 65 Hz band, so the drive cannot lock its firing to the mains.[1]

Likely causes

  • Supply frequency out of range
  • Synchronisation errors caused by a distorted supply

First checks, in this order

  1. Measure the supply frequency.
  2. Look for supply distortion from generators or other converters on the same supply.
  3. Check the supply connections to the drive.

PHASE FAIL: Supply phase missing (FIRST TRIP value 22, ACTIVE TRIPS+ mask 0x0020)

Hits OEE: Availability

What it means: One or more phases of the 3-phase supply is missing.[2][3]

Likely causes

  • Supply phase lost
  • Blown supply fuse
  • Loose supply connection

First checks, in this order

  1. Check the supply connections.
  2. Check the fuses.
  3. This trip cannot be disabled and does not auto restart.

VDC RIPPLE: DC link ripple too high (FIRST TRIP value 25, ACTIVE TRIPS+ mask 0x0100)

Hits OEE: Availability

What it means: The ripple voltage on the DC link is too high, usually because one input phase is missing.[2][3]

Likely causes

  • Missing input phase
  • Blown supply fuse or loose supply connection
  • Badly unbalanced supply

First checks, in this order

  1. Check for a missing input phase.
  2. Check the supply fuses and connections.
  3. Measure the phase to phase voltages for imbalance.

LOST COMMS: Remote communications lost (FIRST TRIP value 13, ACTIVE TRIPS mask 0x1000)

Hits OEE: Availability

What it means: In remote comms mode the COMMS COMMAND word has not been refreshed within COMMS TIMEOUT, so the drive trips.[2][3]

Likely causes

  • COMMS TIMEOUT set too short
  • PLC or fieldbus master stopped writing to the drive
  • Comms cable or option card fault

First checks, in this order

  1. Check COMMS TIMEOUT (tag 309) in the COMMS CONTROL block; 0.0 s disables the check.
  2. Check that the master writes COMMS COMMAND (tag 273) often enough.
  3. Check the comms cable, connectors and option card.

COMMS TIMEOUT: Remote comms timeout (LAST ALARM 0xF010)

Hits OEE: Availability

What it means: In remote sequencing mode the REM.SEQUENCE word was not written within the COMMS TIMEOUT time.[1]

Likely causes

  • PLC or fieldbus master stopped writing REM.SEQUENCE
  • COMMS TIMEOUT set too short
  • Comms cable or option fault

First checks, in this order

  1. Check COMMS TIMEOUT (tag 1204, 0.0 to 60.0 s) in the SEQUENCING block; a non-zero value turns the watchdog on.
  2. Check that the master writes REM.SEQUENCE (tag 536) regularly and that REM.SEQ.ENABLE (tag 535) is set as intended.
  3. Check the comms wiring and option.

COMMS FAULT CODE x: Keypad communication fault

Hits OEE: Availability

What it means: The keypad cannot communicate with the drive; the last character changes with the type of comms error.[1]

Likely causes

  • Keypad faulty
  • Remote cable to the keypad faulty
  • Drive firmware not running

First checks, in this order

  1. Unplug and refit the keypad and its cable.
  2. Try a known good keypad and cable.
  3. Switch the auxiliary supply off and on.
  4. If a good keypad still shows the fault, the control board may not be running: contact Parker.

OP STATION: Keypad disconnected (FIRST TRIP value 12, ACTIVE TRIPS mask 0x0800)

Hits OEE: Availability

What it means: The keypad was disconnected from the drive while the drive was running in local control.[2][3]

Likely causes

  • Keypad accidentally disconnected
  • Loose keypad cable or connector

First checks, in this order

  1. Refit the keypad and secure its cable.
  2. On a remote mounted keypad, check the cable and connectors.
  3. This trip can be disabled in DISABLED TRIPS (tag 231) if the application allows it.

NO OP STATION: Keypad disconnected (NO OP-STATION, LAST ALARM 0xF400)

Hits OEE: Availability

What it means: The keypad was disconnected from the drive while the drive was running in local control.[1]

Likely causes

  • Keypad accidentally disconnected
  • Loose keypad cable or connector

First checks, in this order

  1. Refit the keypad and secure its cable.
  2. On a remote mounted keypad, check the cable and connectors.

STALL TRIP: Motor stall (hex 0x1000)

Hits OEE: Availability

What it means: With the motor stationary (AT ZERO SPEED is TRUE), armature current stayed above STALL THRESHOLD for longer than STALL TRIP DELAY. It only trips when the STALL TRIP alarm is enabled.[1]

Likely causes

  • Motor jammed or mechanically blocked
  • Mechanical brake not released
  • Stall threshold or delay set too low for the process

First checks, in this order

  1. Check the machine for a jam and the brake for release.
  2. Check STALL THRESHOLD (tag 263, default 95%) and STALL TRIP DELAY (tag 224, default 30 s).
  3. STALL TRIP (tag 28) enables or inhibits the alarm; the STALL TRIP diagnostic (tag 112) is set after the delay even when inhibited.

ACCTS FAILED: AC current transformer failure (hex 0x8000)

Hits OEE: Availability

What it means: The AC current transformer plug connection to the power board is missing, so the drive has no armature current feedback. On Frame 5 it also means a load imbalance above 10% between the two parallel stacks.[1]

Likely causes

  • Current transformer plug missing or not seated
  • Frame 5: current imbalance between the parallel power stacks

First checks, in this order

  1. Check the armature current transformer plug is correctly fitted.
  2. Frame 6 and H: an unlit ACCTS PRESENT LED confirms the CT connection is missing.
  3. Frame 5: check the CUR IMBALANCE LED on the Parallel Expansion Board.
  4. The trip stops the contactor closing without current feedback, which matters on external stack controllers.

AUTOTUNE ERROR: Autotune failed (LAST ALARM 0xF001)

Hits OEE: Availability

What it means: The current loop autotune hit an error, for example speed feedback above 20% of rated speed or field current above 6% of rated field current.[1]

Likely causes

  • Motor shaft turning during the armature autotune
  • Field current above 6% in a field off autotune, or field current stopped in a field on autotune
  • Open circuit wiring between drive and armature
  • Discontinuous current boundary above 200% of the stack rating or the motor armature current
  • Large imbalance in the 3-phase supply voltages
  • Hardware fault in the current feedback on the control board

First checks, in this order

  1. Make sure the motor shaft cannot turn during the armature autotune.
  2. Check the field is off when a field off autotune is selected.
  3. Check the armature wiring for an open circuit.
  4. Measure the supply phase voltages for imbalance.
  5. If it still fails, tune the current loop manually or contact Parker.

AUTOTUNE ABORTED: Autotune aborted (written AUTOTUNE ABORT in the trip table, LAST ALARM 0xF002)

Hits OEE: Availability

What it means: The autotune sequence was stopped before it finished.[1]

Likely causes

  • Coast Stop, Program Stop, Enable or Start/Run removed during the autotune
  • AUTOTUNE parameter reset during the sequence
  • Autotune timed out (about 2 minutes)

First checks, in this order

  1. Keep Coast Stop, Program Stop, Enable and Start/Run on for the whole autotune.
  2. Set AUTOTUNE (tag 18) again and restart the sequence.

CONTACTOR DELAY: Contactor failed to close (LAST ALARM 0xF004)

Hits OEE: Availability

What it means: The internal auxiliary 3-phase contactor failed to close.[1]

Likely causes

  • Calibration scaling switch in the wrong position
  • Contactor or its coil wiring faulty

First checks, in this order

  1. Check the position of the calibration scaling switch (manual section Calibration Checks, page 7-3).
  2. Check the main contactor, its coil supply and its wiring.

CONTACTOR FBK: Contactor feedback missing (FIRST TRIP value 14, ACTIVE TRIPS mask 0x2000)

Hits OEE: Availability

What it means: The CONTACTOR CLOSED input of the SEQUENCING LOGIC block stayed FALSE after a run command was given.[2][3]

Likely causes

  • Main contactor did not close
  • Contactor auxiliary contact or its wiring faulty
  • CONTACTOR CLOSED input not linked to the right digital input

First checks, in this order

  1. Check the main contactor closes on a run command.
  2. Check the auxiliary contact and wiring back to the drive input.
  3. Check the link to CONTACTOR CLOSED (tag 1235) in the SEQUENCING LOGIC block.

SPEED FEEDBACK: Speed feedback error (FIRST TRIP value 15, ACTIVE TRIPS mask 0x4000)

Hits OEE: Availability

What it means: SPEED ERROR has stayed above 50% for 10 seconds (default settings). It only works in closed loop vector mode and not during autotune.[2][3]

Likely causes

  • Encoder fault or wiring fault
  • Encoder lines or direction set wrong
  • Drive held in torque or current limit, which causes nuisance trips in torque control

First checks, in this order

  1. Check the encoder, its supply and its cable.
  2. Check ENCODER LINES (tag 566) and ENCODER INVERT (tag 567).
  3. Check THRESHOLD (tag 1649, default 50%) and DELAY (tag 1647, default 10 s) in the SPD FBK TRIP block.
  4. In torque control, set INHIBIT (tag 1648) to TRUE as Parker advises.

OVERSPEED: Motor overspeed (FIRST TRIP value 27, ACTIVE TRIPS+ mask 0x0400)

Hits OEE: Availability

What it means: Speed feedback has stayed above the overspeed THRESHOLD for longer than DELAY.[2][3]

Likely causes

  • Overhauling load driving the motor faster than the setpoint
  • Speed loop badly tuned
  • Speed feedback scaling wrong

First checks, in this order

  1. Check the overspeed THRESHOLD and DELAY settings.
  2. Check the speed loop tuning and the encoder settings.
  3. Check the load is not driving the motor; add braking if needed.
  4. This trip can be disabled in DISABLED TRIPS+ (tag 742).

BRAKE RESISTOR: Brake resistor overload (FIRST TRIP value 10, ACTIVE TRIPS mask 0x0200)

Hits OEE: Availability

What it means: The drive calculates that the external dynamic braking resistor has been overloaded.[2][3]

Likely causes

  • Decelerating a large inertia load too quickly or too often
  • DYNAMIC BRAKING settings not matched to the fitted resistor
  • Resistor too small for the duty

First checks, in this order

  1. Increase DECEL TIME (tag 259) or reduce how often the load is stopped.
  2. Check BRAKE RESISTANCE (tag 77), BRAKE POWER (tag 78) and 1SEC OVER RATING (tag 79) match the resistor data.
  3. Check the resistor rating against the braking duty.
  4. This trip is disabled by default and is enabled in TRIPS STATUS.

BRAKE SWITCH: Brake switch overload (FIRST TRIP value 11, ACTIVE TRIPS mask 0x0400)

Hits OEE: Availability

What it means: The drive calculates that its internal dynamic braking switch has been overloaded.[2][3]

Likely causes

  • Decelerating a large inertia load too quickly or too often
  • Brake resistor value lower than the drive allows

First checks, in this order

  1. Increase DECEL TIME (tag 259) or reduce how often the load is stopped.
  2. Check the resistor value and BRAKE RESISTANCE (tag 77) setting.
  3. This trip is disabled by default and is enabled in TRIPS STATUS.

BRAKE SHORT CCT: Brake resistor overcurrent (FIRST TRIP value 26, ACTIVE TRIPS+ mask 0x0200)

Hits OEE: Availability

What it means: Overcurrent in the brake resistor circuit.[2][3]

Likely causes

  • Brake resistor value below the minimum allowed
  • Short circuit in the brake resistor or its wiring

First checks, in this order

  1. Measure the brake resistor and check it is above the minimum value for the drive.
  2. With power isolated, check the resistor and wiring for shorts to each other and to earth.

CURRENT LIMIT: Current limit trip (FIRST TRIP value 18, ACTIVE TRIPS+ mask 0x0002)

Hits OEE: Availability

What it means: Current stayed above 180% of the stack rated current for 1 second, usually because of a shock load.[2][3]

Likely causes

  • Shock loads on the motor
  • Machine jam

First checks, in this order

  1. Find and remove the cause of the shock load.
  2. Check the machine for jams or binding.

LOW SPEED OVER I: Overcurrent at zero speed (FIRST TRIP value 21, ACTIVE TRIPS+ mask 0x0010)

Hits OEE: Availability

What it means: The motor is drawing too much current (above 100%) at zero output frequency.[2][3]

Likely causes

  • FIXED BOOST or AUTO BOOST set too high

First checks, in this order

  1. Reduce FIXED BOOST (tag 107) and AUTO BOOST (tag 108) in the FLUXING menu.

INPUT 2 BREAK: Analog input 2 signal break (FIRST TRIP value 7, ACTIVE TRIPS mask 0x0040)

Hits OEE: Availability

What it means: A signal break has been detected on analog input 2 (terminal 2).[2][3]

Likely causes

  • Analog input set up wrongly for 4 to 20 mA
  • Break in the external control wiring
  • Transmitter or signal source failed

First checks, in this order

  1. Measure the signal at terminal 2.
  2. Check the ANALOG INPUT 2 type setting.
  3. Check the wiring and the transmitter.
  4. INPUT 2 BREAK (tag 236) in I/O TRIPS can be disabled in DISABLED TRIPS (tag 231).

ANALOG INPUT ERR: Analog input error (FIRST TRIP value 28, ACTIVE TRIPS+ mask 0x0800)

Hits OEE: Availability

What it means: An analog input is out of its valid range.[2][3]

Likely causes

  • Analog input set up wrongly for 4 to 20 mA
  • Short circuit in the external control wiring
  • Remote sensor far over range

First checks, in this order

  1. Check the analog input type settings.
  2. Check the control wiring for shorts.
  3. Check the sensor output.
  4. This trip cannot be disabled and does not auto restart.

AMBIENT TEMP: Drive internal ambient too hot (FIRST TRIP value 16, ACTIVE TRIPS mask 0x8000)

Hits OEE: Availability

What it means: The air temperature inside the drive is too high.[2][3]

Likely causes

  • Cabinet too hot
  • Blocked air flow or clogged filters
  • Cabinet fan failed

First checks, in this order

  1. Check the cabinet temperature, fans and filters.
  2. Check the spacing around the drive.
  3. This trip cannot be disabled.

24V FAILURE: 24 V customer supply low (FIRST TRIP value 20, ACTIVE TRIPS+ mask 0x0008)

Hits OEE: Availability

What it means: The 24 V customer output has fallen below 17 V.[2][3]

Likely causes

  • 24 V customer output short circuited
  • Too much load on the 24 V output

First checks, in this order

  1. Disconnect the loads on the 24 V terminals one by one and measure the voltage.
  2. Check the wiring for shorts to 0 V or earth.
  3. Move heavy loads to an external 24 V supply.

ENCODER 1 FAULT: Encoder option error input (FIRST TRIP value 23, ACTIVE TRIPS+ mask 0x0040)

Hits OEE: Availability

What it means: The error input on the encoder Technology Box is in the error state.[2][3]

Likely causes

  • Encoder or encoder supply fault
  • Encoder cable fault
  • INVERT ENC TRIP set wrong

First checks, in this order

  1. Check the encoder, its supply and its cable.
  2. Check INVERT ENC TRIP (tag 1154); FALSE means normally closed.
  3. ENCODER (tag 1156) in I/O TRIPS shows TRUE when tripped. The DISABLED TRIPS+ default shown in the manual (0x0040) masks this trip.

5703 RCV ERROR: 5703 receive error (hex 0x0800)

Hits OEE: Availability

What it means: Invalid data was received on the P3 port from another drive. It only works when MODE is set to 5703 SLAVE.[1]

Likely causes

  • 5703 setpoint repeater or its fibre optic link faulty
  • Master drive not sending
  • P3 port cable or connection fault

First checks, in this order

  1. Check the 5703 unit, its fibre optic cables and the P3 connection.
  2. Check the master drive is powered and set to 5703 MASTER.
  3. Check MODE (tag 130) on this drive.
  4. 5703 RCV ERROR (tag 111) in the ALARMS menu can inhibit the alarm.

CALIBRATION FAIL: Signal calibration fault (CALIBRATION, LAST ALARM 0xF300)

Hits OEE: Availability

What it means: The drive has detected a signal calibration fault.[1]

Likely causes

  • Hardware failure on the control board

First checks, in this order

  1. Switch the drive off and on again.
  2. If the fault stays, a hardware failure is likely: contact Parker.

REMOTE TRIP: Remote trip from comms (LAST ALARM 0xF006)

Hits OEE: Availability

What it means: The Remote Trip flag in the REM. SEQUENCE control word has been set to zero by the remote master.[1]

Likely causes

  • PLC or fieldbus master cleared the remote trip bit
  • Master program fault

First checks, in this order

  1. Check the remote trip bit written to REM.SEQUENCE (tag 536).
  2. Check REM TRIP INHIBIT (tag 540) and REM TRIP DELAY (tag 541); REMOTE TRIP (tag 542) shows the state.

ENABLE LOW: Enable input low in local mode (LAST ALARM 0xF007)

Hits OEE: Availability

What it means: The drive was asked to run in local mode while the Enable input was low.[1]

Likely causes

  • No 24 V on the Enable input (terminal C5 by default)
  • Enable interlock open

First checks, in this order

  1. Check for 24 V on terminal C5 and the devices wired to it.
  2. ENABLE (tag 497) in the SEQUENCING block shows the input state.

AUX SUPPLY: Auxiliary supply problem (LAST ALARM 0xFF03)

Hits OEE: Availability

What it means: The drive has detected a problem with its auxiliary supply or mains input.[1]

Likely causes

  • Auxiliary supply low or interrupted
  • Mains input problem

First checks, in this order

  1. Check the auxiliary supply voltage and its fuse.
  2. Check the mains input to the drive.

CONFIG ENABLED: Start requested in configuration mode (LAST ALARM 0xF200)

Hits OEE: Availability

What it means: The drive was asked to start while it was in configuration mode.[1]

Likely causes

  • CONFIGURE ENABLE left at ENABLED after changing settings

First checks, in this order

  1. Set CONFIGURE ENABLE to DISABLED.
  2. Perform a PARAMETER SAVE, then start again.

SEQ PRE READY: Power chassis coding missing (LAST ALARM 0xF003)

Hits OEE: Availability

What it means: The drive cannot find its power chassis coding.[1]

Likely causes

  • Power board coding not present
  • Faulty power board or chassis

First checks, in this order

  1. Switch off and on again to confirm.
  2. Parker's remedy is to replace the power board or chassis; contact Parker.

SEQUENCING: Internal sequencing error (LAST ALARM 0xF009)

Hits OEE: Availability

What it means: The drive has an internal sequencing error.[1]

Likely causes

  • Internal drive fault

First checks, in this order

  1. Note the LAST ALARM and HEALTH STORE values.
  2. Contact Parker.

CRITICAL ERROR: Critical error (shown as CRITICAL ERROR xxxx::xxxxxxxx)

Hits OEE: Availability

What it means: The drive has stopped on a critical internal error and shows a numeric error code.[1]

Likely causes

  • Internal firmware or hardware fault

First checks, in this order

  1. Write down the full code shown after CRITICAL ERROR.
  2. Contact Parker with the code and the drive product code.

CHECKSUM FAIL: Non-volatile memory checksum failure (590+: (EEPROM) CHECKSUM FAIL; 690+: * CHECKSUM FAIL *)

Hits OEE: Availability

What it means: At power up the saved parameters failed their memory check, so they were not saved or are corrupted. The drive goes back to factory defaults.[1][2]

Likely causes

  • Parameters not saved before power off
  • Corrupted parameter memory
  • 590+: corrupted UDP file loaded
  • 690+: control board replaced with an unprogrammed board

First checks, in this order

  1. 590+: press E and perform a PARAMETER SAVE; the drive returns to factory defaults, so re-enter or reload your settings.
  2. 690+: press E, which loads and saves Macro 1 defaults and the ENGLISH 50Hz Product Code; then reload your Product Code, then your macro, and do a Parameter Save in that order.
  3. 690+ without a keypad: the HEALTH and RUN LEDs show a short flash; a keypad or PC tool is needed to reset it.
  4. If the data will not save, the drive is faulty and must go back to Parker.

OTHER: Other trip active (FIRST TRIP value 32, ACTIVE TRIPS+ mask 0x8000)

Hits OEE: Availability

What it means: One or more of the extended trips (values 33 to 45, such as the autotune errors, STACK TRIP or POWER LOSS STOP) is active.[2][3]

Likely causes

  • An autotune error
  • STACK TRIP or POWER LOSS STOP

First checks, in this order

  1. Read FIRST TRIP (tag 6) and TRIP 1 (NEWEST) (tag 500) to see the actual trip name.
  2. Look that trip up in this table.

STACK TRIP: Power stack trip (FIRST TRIP value 41)

Hits OEE: Availability

What it means: The drive tripped in the power stage but could not tell whether it was an overcurrent (desaturation) or an overvoltage trip.[2][3]

Likely causes

  • Overcurrent or short circuit at the output
  • Overvoltage from fast deceleration or high supply

First checks, in this order

  1. Work through the OVERCURRENT and OVERVOLTAGE checks.
  2. With power isolated, test the motor and cable insulation.

POWER LOSS STOP: Power loss stop completed (FIRST TRIP value 43)

Hits OEE: Availability

What it means: The power loss stop sequence ramped the speed setpoint to zero, or timed out, after a supply loss.[2][3]

Likely causes

  • Supply interruption or dip with power loss control enabled

First checks, in this order

  1. Check the supply for dips and interruptions.
  2. Check the POWER LOSS CNTRL block settings, for example DECEL TIME (tag 1269).

MAX SPEED LOW: Autotune error: maximum speed too low (FIRST TRIP value 33)

Hits OEE: Availability

What it means: The autotune needs to run the motor at nameplate speed, but MAX SPEED RPM limits it to less.[2][3]

Likely causes

  • MAX SPEED RPM set below the motor nameplate rpm

First checks, in this order

  1. Raise MAX SPEED RPM to at least the motor nameplate rpm, run the autotune, then reduce it again if needed.

NOT AT SPEED: Autotune error: required speed not reached (FIRST TRIP value 35)

Hits OEE: Availability

What it means: During the autotune the motor could not reach the speed it needed.[2][3]

Likely causes

  • Motor shaft not free to turn
  • Motor data entered wrong

First checks, in this order

  1. Make sure the motor shaft turns freely (uncouple the load if possible).
  2. Check the motor nameplate data entered in the drive.

MAG CURRENT FAIL: Autotune error: magnetizing current not found (FIRST TRIP value 36)

Hits OEE: Availability

What it means: The autotune could not find a magnetizing current value that gives the required motor operating condition.[2][3]

Likely causes

  • Motor data wrong, especially nameplate rpm and motor volts
  • Motor not correctly rated for the drive

First checks, in this order

  1. Check the motor data, especially nameplate rpm and motor volts.
  2. Check the motor rating matches the drive.

NEGATIVE SLIP F: Autotune error: negative slip frequency (FIRST TRIP value 37)

Hits OEE: Availability

What it means: The autotune calculated a negative slip frequency, which is not valid.[2][3]

Likely causes

  • Nameplate rpm set higher than the motor base speed

First checks, in this order

  1. Check nameplate rpm, base frequency and pole pairs.

TR TOO LARGE: Autotune error: rotor time constant too large (FIRST TRIP value 38)

Hits OEE: Availability

What it means: The rotor time constant calculated by the autotune is too large.[2][3]

Likely causes

  • Nameplate rpm entered wrong

First checks, in this order

  1. Check the nameplate rpm setting against the motor plate and run the autotune again.

TR TOO SMALL: Autotune error: rotor time constant too small (FIRST TRIP value 39)

Hits OEE: Availability

What it means: The rotor time constant calculated by the autotune is too small.[2][3]

Likely causes

  • Nameplate rpm entered wrong

First checks, in this order

  1. Check the nameplate rpm setting against the motor plate and run the autotune again.

MAX RPM DATA ERR: Autotune data does not cover the maximum speed (FIRST TRIP value 40)

Hits OEE: Availability

What it means: MAX SPEED RPM has been raised beyond the range the autotune measured (up to 30% above the max speed at the time of the autotune).[2][3]

Likely causes

  • MAX SPEED RPM increased after the autotune

First checks, in this order

  1. Run the autotune again with MAX SPEED RPM set to the new, higher value.

OC/OC2: Overcurrent (F708 trip type 2 for OC, 67 for OC2; OC2 only on models above 22 kW)

Hits OEE: Availability

What it means: Output current is too high and the drive has tripped.[4]

Likely causes

  • Acceleration time too short
  • Short circuit at the output
  • Motor rotor locked
  • Motor parameter tuning wrong

First checks, in this order

  1. Lengthen the acceleration time.
  2. Check the motor cable for damage and shorts.
  3. Check whether the motor is overloaded or jammed.
  4. Reduce the V/F (VVVF) compensation value.
  5. Measure the motor parameters again (autotune).

OE: DC over-voltage (O.E., F708 trip type 3)

Hits OEE: Availability

What it means: The DC bus voltage is too high.[4]

Likely causes

  • Supply voltage too high
  • Load inertia too big
  • Deceleration time too short
  • Motor regenerating energy back to the drive
  • Speed loop PID set wrong

First checks, in this order

  1. Check the supply voltage against the drive rating.
  2. Increase the deceleration time.
  3. Fit a braking resistor (optional).
  4. Set the speed loop PID parameters correctly.

OH: Heatsink overheat (O.H., F708 trip type 7)

Hits OEE: Availability

What it means: The drive heatsink is too hot.[4]

Likely causes

  • Ambient temperature too high
  • Poor ventilation
  • Fan damaged
  • Carrier frequency or compensation curve set too high

First checks, in this order

  1. Improve ventilation and clean the air inlet, outlet and heatsink.
  2. Replace the fan if it is damaged.
  3. Lower the carrier frequency or compensation curve.
  4. F745 sets the overheat pre-alarm level, F747 lets the drive cut carrier frequency automatically when hot, F726 and F730 set the overheat protection and its delay.

LU: Under-voltage (L.U., F708 trip type 6)

Hits OEE: Availability

What it means: The voltage on the AC input side is too low.[4]

Likely causes

  • Low supply voltage
  • Under-voltage threshold set wrong

First checks, in this order

  1. Check the supply voltage is normal.
  2. Check the under-voltage threshold F732.

OL1: Inverter overload (O.L1, F708 trip type 5)

Hits OEE: Availability

What it means: The drive itself is overloaded.[4]

Likely causes

  • Load too heavy for the drive

First checks, in this order

  1. Reduce the load and check the gear or belt ratio.
  2. Use a drive with more capacity if the load is normal.

OL2: Motor overload (O.L2, F708 trip type 8)

Hits OEE: Availability

What it means: The motor is overloaded according to the drive's motor protection.[4]

Likely causes

  • Load too heavy for the motor

First checks, in this order

  1. Reduce the load and check the gear or belt ratio.
  2. Use a larger motor if the load is normal.

PF1: Input phase loss (P.F1., F708 trip type 4)

Hits OEE: Availability

What it means: A phase of the 3-phase supply is missing. Single-phase models and 3-phase models of 5.5 kW and below do not have this protection.[4]

Likely causes

  • Supply phase lost or blown fuse
  • Phase loss protection set wrong

First checks, in this order

  1. Check the input power on all three phases.
  2. Check F724 (input phase loss enable) and F728 (trip delay).

PF0: Output phase loss (F708 trip type 17)

Hits OEE: Availability

What it means: A phase is missing in the drive output or motor wiring.[4]

Likely causes

  • Motor faulty
  • Motor wire loose
  • Drive faulty

First checks, in this order

  1. Check the motor wiring for loose connections.
  2. Check the motor windings.
  3. F727 enables output phase loss protection (factory value 0, disabled).

OC1: Overcurrent 1 (F708 trip type 16)

Hits OEE: Availability

What it means: Output current has gone above the over-current 1 level set by F738 (a multiple of drive rated current).[4]

Likely causes

  • Acceleration too fast or shock load
  • Short circuit at the output
  • F738 set too low

First checks, in this order

  1. Work through the OC/OC2 checks.
  2. Check F737 (enable) and F738 (coefficient, factory value 2.50); F739 records the event.

GP: Ground fault

Hits OEE: Availability

What it means: The drive has detected a ground (earth) fault on the output.[4]

Likely causes

  • Motor cable damaged and shorted to earth
  • Motor insulation broken down to earth
  • Drive fault

First checks, in this order

  1. With power isolated, test the motor cable and motor insulation to earth.
  2. Replace the cable or repair the motor as needed.
  3. Also see OC, OC2 and Err4.

AErr: Analog input disconnected (F708 trip type 18)

Hits OEE: Availability

What it means: An analog input signal line is open, so the reference has been lost.[4]

Likely causes

  • Analog signal line disconnected
  • Signal source failed

First checks, in this order

  1. Check and replace the signal line if needed.
  2. Check the signal source.
  3. Check F741 (analog disconnected protection) and F742 (threshold); when used, set the input lower limits F400 and F406 to 1 to 2 V.

CE: Communication timeout (F708 trip type 45)

Hits OEE: Availability

What it means: Serial communication has timed out.[4]

Likely causes

  • Communication fault
  • PC or PLC does not send commands at the set interval

First checks, in this order

  1. Check the communication line is connected reliably.
  2. Check the PC or PLC sends commands regularly.

ESP: External coast stop (external malfunction, F708 trip type 11)

Hits OEE: Availability

What it means: The external coast stop input (DI2 by default) is active, so the drive coasts to a stop and shows ESP.[4]

Likely causes

  • External stop or fault contact wired to DI2 is closed
  • Wiring fault on the DI2 input

First checks, in this order

  1. Check the device wired to DI2 and why it operated.
  2. Clear the external condition, then press O (stop) to reset.

Err4: Current sampling fault (current zero excursion, F708 trip type 15)

Hits OEE: Availability

What it means: The drive current measurement is not reading correctly.[4]

Likely causes

  • Flat ribbon cable loose
  • Current sensor faulty

First checks, in this order

  1. With power isolated and capacitors discharged, check the flat cable inside the drive.
  2. If it stays, contact Parker.

Log it, or the same alarm comes back

A trip stops the drive and with it the extruder, winder, conveyor or mixer it runs, so in OEE terms it is a breakdown. Log the trip message, the drive and the minutes lost.

  • Reason code: the trip plus the drive, for example 590+ MISSING PULSE, coating line unwind, so a trip that comes back on every heavy start shows up as a pattern.
  • Loss bucket: a stop that needs a reset, a part or a technician is an availability loss (breakdown). Stops shorter than your micro-stop threshold go to performance (minor stops). The six big losses page shows where each one belongs.
  • What to count: how often each code fires per week and the minutes it costs. Two numbers a week turn "that alarm comes up sometimes" into a ranked list. The MTBF and MTTR calculator and the downtime cost calculator do the math.

The free OEE tracker logs each stop with its reason and turns the week into a downtime Pareto, so the code that costs the most rises to the top.

For drive faults across brands, fabrico.io has a VFD fault codes guide. A fault code tells you what the drive measured, not what happened at the machine in the seconds before. Fabrico's camera-based OEE software syncs line camera video with machine data, so you can replay the moment the line stopped next to the trip.

Frequently asked questions

What does OVER SPEED mean on a Parker 590?

OVER SPEED (OVERSPEED in the trip table, hex 0x0001 in LAST ALARM and HEALTH WORD) means speed feedback went above 125% of rated speed for 50 ms. It only works with encoder or armature voltage feedback. The usual cause is a badly adjusted speed loop, so retune the speed loop gains and check OVER SPEED LEVEL in the CALIBRATION menu and the speed feedback setup (SPEED FBK SELECT, tag 47).

What does MISSING PULSE mean on a 590+?

MISSING PULSE (hex 0x0002) means one of the six current pulses in the armature current waveform is missing, typically a thyristor that is not firing because of a bad firing plug or connection. It only checks when the load is above 1.5 times the DISCONTINUOUS value (tag 137) and trips after 60 seconds. Check the firing plugs and leads. It does not protect against a thyristor failing during regeneration, so Parker recommends fusing the armature circuit on regenerative drives.

How do I reset a trip on a Parker 690+?

Find and remove the cause first; a heatsink trip will not reset until the heatsink has cooled. Then press STOP on the keypad, or pulse the remote trip reset input (REM TRIP RESET, tag 282). If TRIP RST BY RUN (tag 290) is TRUE, a new run command also clears the trip. The HEALTH LED stops flashing when the reset works. The AUTO RESTART block can reset selected trips automatically.

What does HEATSINK TRIP mean on a Parker SSD drive?

It means the drive heatsink is too hot. On the 590+ DC drive the message is HEATSINK TRIP (hex 0x0008); on the 690+ AC drive it is HEATSINK (FIRST TRIP value 4); on the AC10 it shows as OH. Check the ambient temperature, ventilation and spacing, the cooling fan and its fuse, and clean filters and vents. On the 590+ also compare the motor armature current with the drive current calibration. The drive must cool down before it can be reset.

What does COMMS FAULT CODE mean on a Parker 590+ keypad?

It means the keypad has lost communication with the drive. The 590+ manual lists COMMS FAULT CODE x with three causes: a faulty keypad, a faulty remote keypad cable, or drive firmware that is not running. Refit the keypad and cable, try a known good keypad and cable, and cycle the power. If a good keypad still shows the fault, contact Parker about the control board. The 690+ manuals checked here do not list this message.

Sources

Codes and meanings follow the manufacturer documentation below. Wording is ours, simplified for the shop floor; the manual for your exact model and software version wins if it differs.

  1. 590+ Series DC Digital Drive, Frame 1, 2, 3, 4, 5, 6 and H, Product Manual HA466461U004 Issue 6 (2016, compatible with version 8.x software), Parker Hannifin, hosted on parker.com
  2. 690+ Series AC Drive, Frame B, C, D, E and F, Product Manual HA465492U006 Issue 2 (2016, compatible with version 5.x software), Parker Hannifin, hosted on parker.com
  3. 690+ Series AC Drive Software Product Manual HA465038U005 Issue 5 (2007, Parker SSD Drives), hosted on parker.com
  4. AC10 Series IP20 0-180kW Product Manual HA502320U001 Issue 7 (2021), Parker Hannifin, hosted on parker.com

See the moment the drive tripped

Fabrico, a light MES with computer vision, syncs camera footage with machine and timeline data, so you can replay the exact moment the line stopped and review the cause next to the drive's fault. Cameras also catch short stops and a line that is switched on but not producing, the losses nobody writes down. Machines connect through a PLC, a Fabrico IoT device or an AI camera.

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Related tools: full troubleshooting directory · OEE calculator · downtime cost · MTBF / MTTR · glossary

OEE essentials: OEE calculator · What is OEE · How to improve OEE · Six big losses · Availability · TEEP · Cost of downtime · OEE benchmark · Free OEE tracker · Free OEE software · How to track downtime · How to implement OEE · Light MES vs full MES