Parker AC690 Drive Fault Codes

Troubleshooting a Parker SSD AC690 drive? View the complete reference guide for MMI trip messages, DSE Lite diagnostics, and FAQ to minimize downtime.

Parker AC690 Fault Codes Reference Table

Use the search bar in the table below to quickly find your specific error message.

Fault Code	Cause & Solution
OVERVOLTAGE	Cause: The drive internal dc link voltage is too high. Solution: - The supply voltage is too high - Trying to decelerate a large inertia load too quickly - The brake resistor is open circuit
UNDERVOLTAGE	Cause: The drive internal dc link voltage is too low Solution: - The supply voltage is too low - The supply has been lost - A supply phase is missing
OVERCURRENT	Cause: The motor current being drawn from the drive is too high Solution: - Trying to accelerate a large inertia load too quickly - Trying to decelerate a large inertia load too quickly - Application of shock load to motor - Short circuit between motor phases - Short circuit between motor phase and earth - Motor output cables too long or too many parallel - motors connected to the drive - Fixed or auto boost levels are set too high
HEATSINK	Cause: The drive heatsink temperature is too high Solution: - The ambient air temperature is too high - Poor ventilation or spacing between drives
EXTERNAL TRIP	Cause: User trip caused via control terminals Solution: +24V not present on external trip (e.g. terminal 19, Macro 1).
INPUT 1 BREAK	Cause: A signal break has been detected on analog input 1 (terminal 1) Solution: - Analog input is incorrectly configured for 4-20mA operation - Break in external control wiring
INPUT 2 BREAK	Cause: A signal break has been detected on analog input 2 (terminal 2) Solution: - Analog input is incorrectly configured for 4-20mA operation - Break in external control wiring
MOTOR STALLED	Cause: The motor has stalled (not rotating) Motor loading too great Solution: - Current limit level is set too low - Stall trip duration is set too low - Fixed or auto boost levels are set too high
INVERSE TIME	The inverse time current limit is active: • motor loading is too great: motor current >150% for 60s in Constant duty motor current >110% for 60s in Quadratic duty • fixed or autoboost levels are too high
BRAKE RESISTOR	Cause: External dynamic braking resistor has been overloaded Solution: Trying to decelerate a large inertia load too quickly or too often
BRAKE SWITCH	Cause: Internal dynamic braking switch has been overloaded Solution: Trying to decelerate a large inertia load too quickly or too often
OP STATION	Cause: Keypad has been disconnected from drive whilst drive is running in local control Solution: Keypad accidentally disconnected from drive
LOST COMMS	COMMS TIMEOUT parameter set too short (refer to COMMS CONTROL menu at level 3).
CONTACTOR FBK	The CONTACTOR CLOSED input in the SEQUENCING LOGIC function block remained FALSE after a run command was issued.
SPEED FEEDBACK	SPEED ERROR > 50.00% for 10 seconds.
AMBIENT TEMP	The ambient temperature in the drive is too high.
MOTOR OVERTEMP	Cause: The motor temperature is too high Solution: - Excessive load - Motor voltage rating incorrect - FIXED BOOST and/or AUTO BOOST set too high - Prolonged operation of the motor at low speed without forced cooling - Check setting of INVERT THERMIST parameter in I/O TRIPS menu at level 3. - Break in motor thermistor connection
CURRENT LIMIT	Cause: If the current exceeds 180% of stack rated current for a period of 1 second, the drive will trip. This is caused by shock loads. Solution: Remove the cause of the shock load.
24V FAILURE	Cause: The 24V customer output has fallen below 17V. Solution: - 24V customer output is short circuited. - Excessive loading.
LOW SPEED OVER I	Cause: The motor is drawing too much current (>100%) at zero output frequency. Solution: FIXED BOOST and/or AUTO BOOST set too high (refer to FLUXING menu at level 4).
PHASE FAIL	Cause: One or more phases of the 3-phase supply is missing. Solution: - Check supply connections. - Check fuses.
ENCODER 1 FAULT	The Error input on the Encoder TB is in the Error state.
DESAT (OVER I)	Instantaneous overcurrent. Refer to OVERCURRENT in this table.
VDC RIPPLE	Cause: The dc link ripple voltage is too high. Solution: Check for a missing input phase.
BRAKE SHORT CCT	Cause: Brake resistor overcurrent. Solution: Check resistance brake resistor value is greater than minimum allowed.
OVERSPEED	Cause:  Speed feedback has exceeded the THRESHOLD for a period greater than DELAY.
ANALOG INPUT ERR	Cause: Analog input is incorrectly configured for 4-20mA operation. Solution: - Short circuit in external control wiring. - Extreme over-range of remote sensor.
UNKNOWN	An unknown trip - refer to Parker SSD Drives.
OTHER	One or more of the trips listed below have tripped.
MAX SPEED LOW	Cause & Solution: During Autotune the motor is required to run at the nameplate speed of the motor. If MAX SPEED RPM limits the speed to less than this value, an error will be reported. - Increase the value of MAX SPEED RPM up to the nameplate rpm of the motor (as a minimum). - It may be reduced, if required, after the Autotune is complete.
MAINS VOLTS LOW	Cause: The mains input voltage is not sufficient to carry out the Autotune. Solution: Re-try when the mains has recovered.
NOT AT SPEED	Cause: The motor was unable to reach the required speed to carry out the Autotune. Solution: 1. Possible reasons include: - motor shaft not free to turn - the motor data is incorrect
MAG CURRENT FAIL	Cause: It was not possible to find a suitable value of magnetising current to achieve the required operating condition for the motor. Solution: - Check the motor data is correct, especially nameplate rpm and motor volts. - Also check that the motor is correctly rated for the drive.
NEGATIVE SLIP F	Cause: Autotune has calculated a negative slip frequency, which is not valid. Solution: - Nameplate rpm may have been set to a value higher than the base speed of the motor. - Check nameplate rpm, base frequency, and pole pairs are correct.
TR TOO LARGE	Cause: The calculated value of rotor time constant is too large. Solution: Check the value of nameplate rpm.
TR TOO SMALL	Cause: The calculated value of rotor time constant is too small. Solution: Check the value of nameplate rpm.
MAX RPM DATA ERR	Cause: This error is reported when the MAX SPEED RPM is set to a value outside the range for which Autotune has gathered data. Autotune gathers data on the motor characteristics up to 30% beyond “max speed rpm”. Solution: - If MAX SPEED RPM is later increased beyond this range, the drive had no data for this new operating area, and so will report an error. - To run the motor beyond this point it is necessary to re- autotune with MAX SPEED RPM set to a higher value.
STACK TRIP	Cause: The drive was unable to distinguish between an overcurrent/Dsat or overvoltage trip.
LEAKGE L TIMEOUT	Cause: The leakage inductance measurement requires a test current to be inserted into the motor. Solution: - It has not been possible to achieve the required level of current. - Check that the motor is wired correctly.
POWER LOSS STOP	Cause: Power Loss Stop sequence has ramped Speed Setpoint to zero or timed out.
MOTR TURNING ERR	Cause: The motor must be stationary when starting the Autotune.
MOTR STALLED ERR	Cause: The motor must be able to rotate during Autotune.

 

How to Read AC690 Faults via DSE Lite

To get the most accurate diagnostic data in 2026, it is highly recommended to connect your PC to the drive using the Parker DSE Lite (Drive System Explorer) software. This tool provides deeper insights than the standard 6901 keypad.

• Trip Log: Access the “Trips” menu within the software to view the history of the last 10 events. This helps identify recurring issues.
• First Trip Tag: In DSE Lite, look for the “First Trip” parameter within the Sequencing Logic. This identifies which specific fault initiated the shutdown if multiple alarms occurred simultaneously.
• Oscilloscope/Scope Function: The DSE Lite software allows you to trend motor current, DC link voltage, and speed feedback in real-time or capture the moments leading up to a trip for detailed root-cause analysis.

Frequently Asked Questions (FAQ)

Q: What is the difference between an Alarm and a Trip?

A: An Alarm alerts you to a condition that requires attention (such as “Motor Over Temperature”) but may allow the drive to continue running for a short period or until a threshold is breached. A Trip immediately disables the drive output and stops the motor to prevent hardware damage.

Q: How do I reset a Parker AC690 fault?

A: Once the fault condition is cleared, you can reset the drive by pressing the STOP/RESET key on the keypad, toggling the configured Digital Input (often Terminal 10), or sending a reset command via the communications module (Profibus, DeviceNet, etc.).

Q: Where is the fault history stored?

A: Fault history is stored in the Trips History menu. On the physical keypad, navigate to System > Trips > Trip History to view the last 10 trip events stored in memory.