UniMac Washer Error Code Ed10: Low DC Bus Message
Ed10 on a UniMac UC-series washer-extractor with a motor drive is a low DC bus message, meaning the internal voltage that powers the motor dipped below normal. The cycle continues and no action is needed. If it shows often or the machine stops, the supply to the machine should be checked.
Low: a notice only; the unit keeps running.
What does UniMac error code Ed10 mean?
On UniMac UC-series washer-extractors such as the UCH020GNF with the motor drive, Ed10 is a low DC bus message. The drive turns incoming AC into an internal DC voltage that runs the motor, and it keeps watching that voltage. When it dips below its normal level, the drive reports Ed10 as a notice. Unlike the drive stop codes, this one does not end the cycle, and no action is required from the operator. Only washers in Design 2 or Design 3 report it. A brief dip is common at the moment the motor starts, because the motor pulls a surge of current through a supply that sags slightly. If the message appears often, a weak supply or a sag when the machine starts may be the reason.
Affected models and control systems
Listed for UniMac UC-series washer-extractors with a motor drive (CHM495R family, 20-100 lb), such as the UCH020GNF. The manual limits Ed10 to Design 2 and 3 models.
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
- Ed10 appears briefly while the machine keeps running
- Message shows at spin start or when another machine starts nearby
- Lights on the same circuit dim at the same moment
- Occasional slower spin-up
Possible causes
Listed in UniMac's documentation
- Supply voltage that dips when the motor starts
- Other equipment on the circuit pulling voltage down
- Loose or corroded wiring at the disconnect
- Drive input that reacts to a brief dip
Other likely causes — what usually sits behind error code Ed10 on this control. A technician confirms which one it is before any part is replaced.
- A shared panel where a dryer or another washer starts at the same time as this one
- Undersized wiring to the washer that sags under motor starting current
- A warm, damp disconnect where terminals have developed resistance over time
Safe checks before calling for service
- Let the cycle finish. The machine keeps going on its own.
- Note when Ed10 appears, for example at spin start.
- Avoid starting other large machines on the same circuit at the same moment.
- If it shows often or the machine stops, call us.
- Write down the time of day for the next service call.
How a technician diagnoses error code Ed10
- Read the code and ask when it appears and what else is running.
- Measure the supply voltage at the disconnect while the motor starts, and watch for sag.
- Inspect the disconnect and terminal connections for heat marks and tightness with the circuit locked out.
- Check the wire size and run length to the machine against the nameplate.
- Correct the wiring or circuit loading first, and look at the drive only if the supply measures steady.
- Voltage readings during motor start mean live measurements on a 208-240 V feed.
- A weak connection at the disconnect or panel is an electrical repair that needs a qualified person and a lockout.
- The drive's input stage is inside the machine, and judging it takes measurements under load.
How error code Ed10 differs from similar codes
Ed10 is only a notice of a dip. Ed02 is the opposite condition, a DC bus that goes too high and stops the cycle.
Technical reference
- Document
- Washer-Extractor Programming CHM495R_SVG, Part No. F8208501ENR10, March 2017, Error Codes (pp. 36-37)
- Maker documentation
- UniMac owner support
- Edition
- Part No. F8208501ENR10, March 2017
- Models / control
- CHM495R family washer-extractor front-end control (20-100 lb)
- Section
- Error Codes table, pp. 36-37 (E Pr only on Design 1 models; Ed01-Ed11 on Design 2 and 3 models)
- 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 washer error codes
Do I need to do anything when Ed10 appears?
No. The cycle continues. Only repeated occurrences or a stopped cycle call for a check.
Why does Ed10 show at spin start?
The motor draws a surge of current at start, which can pull a weak supply down for a moment.
Will Ed10 become a stop code?
It can if the supply keeps sagging, which is why we suggest looking into frequent occurrences.
Need help with UniMac error code Ed10?
A technician confirms the cause on site and gives you the price in writing before any work starts.