Emerson Commander SK Advanced User Guide & Manual

Struggling with troubleshooting and repair? Keep your equipment running smoothly by using the following guide to diagnose any trip codes. The following are some of the common errors you might encounter:

Emerson Commander SK Fault & Trip Codes by Control Techniques

Trip Code Condition Possible Cause
UU DC Bus under voltage Low AC Supply Voltage

Low DC Bus voltage when supplied by an external DC power supply

OU DC Bus over voltage Deceleration rate set too fast for the inertia of the machine

Mechanical load driving the motor

OI.AC** Drive output instantaneous over current Insufficient ramp times

Phase to phase or phase to ground short circuit on the drives output

Drive requires autotuning to the motor

Motor or motor connections changed, re-autotune drive to motor

OI.br** Braking Resistor instantaneous over current Excessive current in braking resistor

Braking resistor value to small

O.SPd Over Speed Excessive motor speed (typically caused by a mechanical load driving the motor
tunE Autotune stopped before completion Run command removed before autotune compelte
It.br I2t on Braking Resistor Excessive braking resistor energy
lt.AC l2t on drive output current Excessive Mechanical load

High impedance phase to phase or phase to ground short circuit at drive output

Drive requires re-autotuning to motor

O.ht1 IGBT over heat based on dries thermal model Over heat software thermal module
O.ht2 Over heat based on drives heatsink Heatsink temperature exceeds maximum allowable
th Motor thermistor trip Excessive motor temperature
O.Ld1* User +24v or digital output overload Excessive load or short circuit on +24v output
cL1 Analogue input 1 current mode, current loss Input current less than 3mA when 4-20 or 20-4mA modes selected
SCL Serial communication loss time-out Loss of communication when drive is under remote control
EEF Internal Drive EEPROM trip Possible loss of parameter values
PH Input phase imbalance or input phase loss One of the input phases has become disconnected from the drive (applies to 200/400v three phase drives only, not dual rated drives.
rS Failure to measure motors stator resistance Motor too small for drive

Motor cable disconnected during measurement

C.Err SmartStick data error Bad connection or memory corrupt within SmartStick
C.dAt SmartStick data does not exist New/empty SmartStick being read
C.Acc SmartStick read/write error fail Bad connection or faulty SmartStick
C.rtg SmartStick/drive rating change Already programmed SmartStick read by a drive of a different rating
O.cL Overload on current loop input Input current exceeds 25mA
HFxx trip Hardware faults Internal drive hardware fault

HF01 to HF03
Not used
HF04
Low DC bus at power up- may indicate an AC Input or pre-charge problem
HF05
No internal handshake signal from second processor (DSP) at start up
HF06
Unexpected interrupt
HF07
Watchdog failure
HF08
Interrupt crash (code overrun)
HF09 to HF10
Not used
HF11
Access to the EEPROM failed- tried to read stored parameter data but failed
HF12 to HF19
Not used
HF20
Power stage – code error Tried to read power board and read back erroneous
HF21
Power stage – unrecognized frame size
HF22
Overcurrent detection at power up- possible output short or bridge failure
HF23
DSP software overrun
HF24
Not Used
HF25
DSP Communications failure- communication from main to 2nd processor
HF26
Soft start relay failed to close; or soft start monitor failed; or braking
IGBT short circuit at power up
HF27
Power stage thermistor fault
HF28
Power circuit thermistor 2 or 3 fault Internal fan fault on size 3 only
HF29
Fan failure (current too high – only on drives with a fan) see note below
HF30
Not used
HF31
Internal Cap Bank Fan failure- check for fan rotation/blockage Size 4 and up
HF32
Power circuit temperature feedback multiplexer failure

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26 thoughts to “Emerson Commander SK Advanced User Guide & Manual”

  1. HF04
    Low DC bus at power up- may indicate an AC Input or pre-charge problem
    What are best ways to troubleshoot clear this code above

    1. Good morning , i have an error ” HF04 ” on my driver .

      i want a way to fix this error.

      thank you

  2. HF20
    Power stage – code error Tried to read power board and read back erroneous.
    What are best ways to troubleshoot clear this code above

  3. Have a HF-26 Fault anything that I can check to correct this cycling power and reset pushbutton have no effect.

      1. CHECK YOUR POWER PACK CCT THERE IS A RELAY AT LEFT HAND CONNER CHECK IF OK OR NOT. OTHERWISE REPLACE

  4. A/C voltage phase loss alarm, if i discontact from the compressor the alarm goes, if i wire the compressor back to the inverter the code instantly appears.
    is my compressor faultly or the inverter

  5. good day, I have a problem of HF19 errors on our emerson drives, would you kindly advise how resolve this problem

  6. good day, I have a problem of HF19 errors on our emerson drives, would you kindly advise how resolve this problem

  7. HF20
    Power stage – code error Tried to read power board and read back erroneous,

    HF26
    Soft start relay failed to close; or soft start monitor failed; or braking

    how to fix this error

  8. hi,
    please help me on Emerson Unidrive M200. my drive shows ER 01.5C fault.
    What fault is ER01.5C ?
    many thanks
    Sbu Sibeko

  9. I have HF07 and HF25 errors on Commander SK emerson VFD. How can I fix them.
    HF07: Watchdog failure

    HF25: DSP Communications failure- communication from main to 2nd processor

  10. TRY TO RUN YOUR COMRERSSOR WITHOUT THE DRIVE. IF IT RUNS CHECK YOUR AMPERAGE AND CONFIRM SAME ON THE DRIVE SETTINGS

  11. Anyone, my commander SK is not giving any current output. May i now what is the fault….
    L1,L2,L3 input but no out from U,V,W to contactor.

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