Understanding trip codes is an important part of keeping your equipment running smoothly. Below are some of the more common codes you may come across when using your Control Techniques Unidrive M200 series drive:
|Trip Code||Condition||Possible Cause|
|C.Acc||NV Media Card Write fail||Unable to access the NV Media Card|
|C.by||NV Media Card cannot be
accessed as it is being accessed
by an option module
|An attempt has been made to access a file on NV Media Card,
but the NV Media Card is already being accessed by an option
module. No data is transferred.
|C.cPr||NV Media Card file/data is different
to the one in the drive
|A C.cPr trip is initiated if the parameters on the NV Media Card
are different to the drive
|C.d.E||NV Media Card data location
already contains data
|Attempt has been made to store data on a NV Media Card in a
data block which already contains data.
|C.dAt||NV Media Card data not found||Attempt has been made to access non-existent file or block on
the NV Media Card.
|C.Err||NV Media Card data structure
|Attempt has been made to access the NV Media Card but an
error has been detected in the data structure on the card.
Resetting the trip will cause the drive to erase and create the
correct folder structure.
|C.FuL||NV Media Card full||There is not enough space left on the card.|
|C.OPt||NV Media Card trip; option
modules installed are different
between source drive and
|The parameter data or default difference data is being
transferred from the NV Media Card to the drive, but the option
module category is different between the source and destination
|C.Pr||NV Media Card data blocks are not
compatible with the drive derivative
|If Drive Derivative is different between the source and target
drives. Refer to the Control User Guide.
|C.rdo||NV Media Card has the Read Only
|Attempt has been made to modify a read-only NV Media Card or
a read-only data block.
|C.rtg||NV Media Card trip; Option module
file transfer has failed
| The C.SL trip is initiated, if the transfer of an option module file
to or from a module failed because the option module does not
|C.tyP||NV Media Card parameter set not
compatible with current drive mode
|The drive mode in the data block on the NV Media Card is
different from the current drive mode.
|cL.A1||Analog input 1 current loss||Current loss was detected in current mode on Analog input 1
|CL.bt||Trip initiated from the Control Word||Initiated by setting bit 12 on the control word when the control
word is enabled. Refer to the Parameter Reference Guide
|Cur.c||Current calibration range||Current calibration range error.|
|Cur.O||Current feedback offset error||Current offset is too large to be trimmed.|
|d.Ch||Drive parameters are being
|A user action or a file system write is active that is changing the
drive parameters and the drive has been commanded to enable.
|dEr.E||Derivative file error||Contact the supplier of the drive.|
|dEr.I||Derivative product image error||Contact the supplier of the drive.|
|dESt||Two or more parameters are
writing to the same destination
|The dESt trip indicates that destination output parameters of two
or more logic functions within the drive are writing to the same
|dr.CF||Drive configuration||Contact the supplier of the drive.|
|EEF||Default parameters have been
|The EEF trip indicates that default parameters have been
loaded. The exact cause/reason of the trip can be identified from
the sub-trip number (Refer to the Control User Guide).
|Et||An External trip is initiated||The cause of the trip can be identified from the sub trip number
displayed after the trip string.
Sub-trip = 1 Reason - External Trip =1
Refer to the Control User Guide
|FAn.F||Fan fail||Indicates the fan or fan circuitry has failed|
|Fi.Ch||File changed||A file has been changed, power cycle to clear the trip|
|FI.In||Firmware Incompatibility||The user firmware is incompatible with the power firmware|
|HFxx trip||Hardware faults||Internal drive hardware fault (Refer to the Control User Guide).|
|It.Ac||Output current overload timed out
|The It.Ac trip indicates a motor thermal overload based on the
output current and motor thermal time constant. The drive will
trip on It.Ac when the accumulator gets to 100 %.
This can occur when:
• There is excessive mechanical load
• Ensure the load is not jammed / sticking
• Check the load on the motor has not changed
• Ensure the motor rated current is not zero
|It.br||Braking resistor overload timed out
|Braking resistor overload has timed out. This can be caused by
excessive braking resistor energy
|no.PS||No power board||No communication between the power and control boards.|
|O.Ld1||Digital output overload||The total current drawn from the AI-Adaptor 24 V supply or from
the digital output has exceeded the limit.
|O.SPd||Motor frequency has exceeded the
over frequency threshold
|Excessive motor speed (typically caused by mechanical load
driving the motor).
|Oh.dc||DC bus over temperature||DC bus component over temperature based on a software
|Oht.C||Control stage over-temperature||Control stage over-temperature detected.|
|Oht.I||Inverter over temperature based
on thermal model
|IGBT junction over-temperature has been detected based on a
software thermal model.
|Oht.P||Power stage over temperature||This trip indicates that a power stage over-temperature has
|OI.A1||Analog input 1 over-current||Current input on analog input 1 exceeds 24 mA.|
|OI.AC||Instantaneous output over current
|The instantaneous drive output current has exceeded.The set
• Increase acceleration/deceleration rate
• If seen during autotune reduce the voltage boost
• Check for short circuit on the output cabling
• Check integrity of the motor insulation using an insulation
• Is the motor cable length within limits for the frame size
• Reduce the values in the current loop gain parameters
|OI.br||Braking IGBT over current
detected: short circuit protection
for the braking IGBT activated
|Over current has been detected in braking IGBT or braking
IGBT protection has been activated.
• Check brake resistor wiring
• Check braking resistor value is greater than or equal to the
minimum resistance value
• Check braking resistor insulation
|OI.SC||Output phase short-circuit||Over-current detected on drive output when enabled.|
|Out.P||Output phase loss detected||Phase loss has been detected at the drive output.|
|OV||DC bus voltage has exceeded the
peak level or maximum continuous
level for 15 seconds
| The OV trip indicates that the DC bus voltage has exceeded the
• Increase Deceleration Rate 1 (Pr 04)
• Decrease the braking resistor value (staying above the
• Check nominal AC supply level
• Check for supply disturbances which could cause the DC
bus to rise
• Check motor insulation using a insulation tester
|P.dAt||Power system configuration data
|Contact the supplier of the drive.|
|PAd||Keypad has been removed||The PAd trip indicates that the drive is in keypad mode and the
keypad has been disconnected from the drive.
|Pb.bt||Power board is in bootloader mode||Power board is in bootloader mode|
|Pb.Er||Communication has been lost /
errors detected between power
|Communications loss between power and control.|
|Pb.HF||Power board HF||Power processor hardware fault - contact the supplier of the
|Pd.S||Power down save error||Error has been detected in the power down save parameters
saved in non-volatile memory.
|PH.Lo||Supply phase loss||The drive has detected an input phase loss or large supply
|PSU||Internal power supply fault||One or more internal power supply rails are outside limits or
|r.All||RAM allocation error||Option module derivative image has requested more parameter
RAM than is allowed.
|r.b.ht||Hot rectifier/brake||Over-temperature detected on input rectifier or braking IGBT.|
|rS||Measured resistance has
exceeded the parameter range
|The measured stator resistance during an autotune test has
exceeded the maximum possible value of Stator Resistance.
Refer to the Control User Guide.
|SCL||Control word watchdog has timed
|The control word has been enabled and has timed out|
|SL.dF||Option module in option slot 1 has
|Option slot 1 on the drive is a different type to that installed
when parameters were last saved on the drive.
|SL.Er||Option module in option slot 1 has
detected a fault
|Option module in option slot 1 on the drive has detected an
|SL.HF||Option module 1 hardware fault||Option slot 1 on the drive has indicated a hardware fault.|
|SL.nF||Option module in option slot 1 has
|The option module in option slot 1 on the drive has been
removed since the last power up.
|SL.tO||Option module watchdog function
|The option module installed in Slot 1 has started the option
watchdog function and then failed to service the watchdog
|So.St||Soft start relay failed to close, soft
start monitor failed
|Soft start relay in the drive failed to close or the soft start
monitoring circuit has failed.
|St.HF||Hardware trip has occurred during
last power down
|Hardware trip (HF01 –HF19) has occurred and the drive has
been power cycled. Enter 1299 to Pr 00 or xx.000 to clear trip
|Sto||No Safe Torque Off board fitted||Internal STO board not fitted correctly.|
|th||Motor thermistor over-temperature||The motor thermistor connected to terminal 14 (digital input 5)
on the control connections has indicated a motor over
|th.br||Brake resistor over temperature||The th.br trip is initiated if the hardware based braking resistor
thermal monitoring is connected and the resistor overheats.
|tH.Fb||Internal thermistor has failed||Internal thermistor has failed.|
|thS||Motor thermistor short circuit||The motor thermistor connected to terminal 14 (digital input 5)
on the control connections, is short circuit or low impedance
|tun.S||Autotune test stopped before
|The drive was prevented from completing an autotune test,
because either the drive enable or the drive run signals were
|tun.1||Autotune 1||The drive has tripped during a rotating autotune. The cause of
the trip can be identified from the sub-trip number.
Sub-trip-2 Reason=The motor did not reach the required speed during rotating auto-tune or mechanical load measurement.
Refer to the Control User Guide
|tun.3||Autotune 3||RFC-A mode only.
The drive has tripped during a rotating auto-tune or mechanical
load measurement. The cause of the trip can be identified from
the associated sub-trip number
Sub-trip-1 Reason=Measured inertia has exceeded the parameter range during a mechanical
Sub-trip-3 Reason=The mechanical load test has been unable to identify the motor inertia
Refer to the Control User Guide.
|U.OI||User OI ac||The U.OI trip is initiated if the output current of the drive exceeds
the trip level set by User Over Current Trip Level. Refer to the
Control User Guide.
|U.S||User Save error / not completed||The U.S trip indicates that an error has been detected in the user save parameters saved in non-volatile memory.|
|UP.uS||User Program trip||This trip can be initiated from within an onboard user program. Refer to the Control User Guide.|
|UPrG||User Program||An error has been detected in the onboard user program image.
Refer to the Control User Guide.
In any mode, an alarm is an indication given on the display by alternating the alarm string with the drive status string display. If an action is not taken to eliminate any alarm except "tuning”, the drive may eventually trip. Alarms are not displayed when a parameter is being edited.
|br.res||Brake resistor overload. Braking Resistor Thermal Accumulator in the drive has
reached 75.0 % of the value at which the drive will trip.Refer to the Power
|OV.Ld||Motor Protection Accumulator in the drive has reached 75.0 % of the value at
which the drive will trip and the load on the drive is >100 %, reduce motor current
(load). Refer to the Parameter Reference Guide
|d.OV.Ld||Drive over temperature. Percentage Of Drive Thermal Trip Level in the drive is
greater than 90 %. Refer to the Parameter Reference Guide
|tuning||The autotune procedure has been initialized and an autotune is in progress.|
|LS||Limit switch active. Indicates that a limit switch is active and that is causing the
motor to be stopped
|Lo.AC||Low voltage mode. See Low AC Alarm in the Control User Guide|
|I.AC.Lt||Current limit active. See Current Limit Active in the Control User Guide|
|24.LoSt||t 24V backup not present. See 24V Alarm Loss Enable in the Control User Guide|
If you have an AC / DC drive module breakdown or stability issue our engineers are able to analyse the whole machine to identify where the control issues lie. Our extensive experience in retrofit and new projects means we have the knowledge to look deep into the control system where we commonly find the peripheral devices are faulty rather than the drive module.
Our team of engineers are able to offer on site service and breakdown support throughout the UK to get you up and running again quickly.
If you have a faulty drive but don't require on site support, Drives and Automation are able to repair them at our repair center in Telford. Our trained engineers will strip down your drive and send you a repair quotation. If you are happy to proceed we will repair the drive, clean it and load test it before returning it to you. Fast turnarounds are usually no problem!
If you are wanting to replace your M200 with a new one or purchase additional modules, Drives and Automation will be happy to help. Visit our online store today: