Randell uHi Error Code
Line Voltage Too High alarm on the Danfoss controller
Source: Randell/8148n-290-pcb__rd-8000-290-9000w-290-spm.pdf
What does Randell uHi mean?
On a Randell prep table with the Danfoss controller, uHi is the Line Voltage Too High alarm. The Danfoss controller monitors supply voltage and will alarm when the incoming line voltage rises above its acceptable range. Operating outside the rated voltage can harm the compressor, and the manual warns that exceeding voltage limits can void the warranty.
Symptoms
- Display shows uHi with the alarm LED lit
- Unit may not run or the compressor may not receive output
- Other equipment on the same supply may show voltage issues
- Cabinet temperature may rise while the alarm is active
Common causes
- Incoming line voltage above the unit's rated range
- Supply voltage fluctuating beyond plus or minus 10 percent of the data-tag value
- Shared or improperly wired circuit instead of a dedicated line
- Building power supply problem
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Diagnostic steps
Confirm the alarm
Verify the Danfoss display reads uHi, the Line Voltage Too High alarm.
Verify the power source voltage
The Danfoss table directs verifying the voltage of the power source; the manual specifies this reading be performed by a qualified technician.
Check the supply circuit
Confirm the unit is on its own dedicated line, as the manual requires, rather than sharing a circuit that may distort voltage.
Compare against the data tag
Condensing units are designed for plus or minus 10 percent of the data-tag voltage; confirm the supply falls within that range.
Contact service
The table directs contacting service for this alarm; call 888-994-7636 to address a confirmed over-voltage condition.
When to call a professional
Voltage measurement at the supply must be done by a qualified technician, as both the Danfoss code table and the manual's installation warnings state. Call a qualified electrician or a Randell Authorized Service Agent to verify and correct the line voltage, since over-voltage can damage the compressor and void warranty. Do not attempt live electrical readings yourself; reach service at 888-994-7636.
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Other Randell Error Codes
Control probe alarm on the Carel controller (air/control temperature sensor)
Defrost probe alarm on the Carel controller (evaporator/defrost temperature sensor)
Open door alarm on the Carel controller
Low temperature alarm (Carel LO / Danfoss Lo)
High temperature alarm (Carel HI / Danfoss Hi)
Dirty condenser alarm on the Carel controller
Condenser Temperature High Limit alarm on the Danfoss controller
Line Voltage Too Low alarm on the Danfoss controller
Continuous Compressor Runtime alarm on the Danfoss controller
S1 Sensor Failure on the Danfoss controller
S2 Sensor Failure on the Danfoss controller
S3 Sensor Failure on the Danfoss controller
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