UniMac Washer-Extractor Error Code E d 23: Fatal IPM Over Current
E d 23 is a fatal IPM over current shunt error on a UniMac QN washer-extractor. The drive's power module sensed a sudden surge of current and shut down fast. Cut power, leave the motor checks to a technician, and call us.
High: a fatal over current shutdown means the machine must not return to production until the cause is found.
- Code
- E d 23
- Maker
- UniMac
- Equipment
- Industrial laundry
- Applies to
- CHM1792C family washer-extractor (QN models, 20-100 lb) front-end control
What does UniMac error code E d 23 mean?
On a UniMac QN washer-extractor such as the UCA020QN, the drive uses a power module, the IPM, to switch current to the motor. A shunt in that circuit measures the current. E d 23 means the shunt saw a surge so large and so sudden that the drive shut down immediately, and it marks the event as fatal. The cycle stops, and the machine needs a technician's attention before it is used again for production.
A sudden surge tends to come from a hard electrical short or a locked drum. A shorted motor winding can do it. So can a stuck drum, because a motor that cannot turn draws a great deal of current. Motor leads with damaged insulation, shorting to ground or to each other, behave the same way. The last candidate is the drive power module itself, which may have failed and now passes too much current.
Cutting power resets the message, but the cause remains, and starting the motor again into a short can damage the drive further.
Affected models and control systems
E d 23 is listed for the CHM1792C family, QN washer-extractors from 20 to 100 lb, with the front-end control and drive board. The example model is the UCA020QN.
Code numbers and their meaning can change between control generations. We match the full model and control before acting on a code.
What you may notice
- The display shows E d 23 and the cycle stops at once
- A click or hum from the drum as the motor tries to start
- The code returns the moment a cycle calls for motor power
- A breaker may trip with the code
Possible causes
Listed in UniMac's documentation
- A shorted motor winding that draws a sudden surge of current
- A jammed drum that will not turn when the motor starts
- Motor leads with damaged insulation that short to ground or each other
- A drive power module that has failed and passes too much current
Other likely causes — what usually sits behind error code E d 23 on this control. A technician confirms which one it is before any part is replaced.
- Motor harness rubbed through where it passes the frame
- Water that reached the motor terminal box and created a path to ground
- Drum jammed by an object that slipped between basket and shell
- Power module damaged by an earlier surge so it conducts when it should not
Safe checks before calling for service
- Cut power to the washer first, which resets the message.
- With power off and the drum still, see whether the empty drum turns freely, without forcing it.
- Leave the motor phase checks to a technician, which is what the maker's step needs.
- Please call us when E d 23 appears again, and tell us whether the drum turned freely.
How a technician diagnoses error code E d 23
- Read the code and the history of earlier drive errors.
- Lock out the machine and confirm the drum turns freely by hand.
- Disconnect the motor leads from the drive and test each winding to ground and to the others.
- Inspect the motor harness and terminal box for damage and moisture.
- Test the drive output stage with the motor disconnected.
- Replace the motor, harness or drive only after the matching test fails.
- Testing motor windings and drive outputs means working with the cabinet open on 208 to 240 V equipment.
- A short in the motor circuit can damage a new drive immediately if it is not found first.
- Telling a jammed drum from a shorted winding requires insulation and resistance testing.
Technical reference
- Document
- Washer-Extractor Programming CHM1792C_SVG, Part No. F8641001ENR4, Error Codes Table 29 (pp. 100-107)
- Maker documentation
- UniMac owner support
- Edition
- Part No. F8641001ENR4, January 2020
- Models / control
- CHM1792C family washer-extractor (QN models, 20-100 lb) front-end control
- Section
- Error Codes, Table 29, pp. 100-108 (PDF pages equal printed pages)
- Checked
- October 2026
We use the maker's document to read the code and do not reproduce it. Always confirm the complete model and control before applying these steps.
Related UniMac industrial laundry error codes
Can I try a restart to see if it goes away?
One restart is harmless, but a repeat means the surge is real. Starting again and again risks harming the drive.
Is E d 23 the same as E d 24?
No. E d 23 is a sudden surge caught by the shunt, while E d 24 is too much current held for too long.
Is it the drum or the electrics?
It can be either. A stuck drum and a shorted winding both pull a surge, so a technician tests both.
Need help with UniMac error code E d 23?
A technician confirms the cause on site and gives you the price in writing before any work starts.