Randell uLi

What does Randell uLi mean?

On a Randell prep table with the Danfoss controller, uLi is the Line Voltage Too Low alarm. The controller monitors supply voltage and alarms when incoming line voltage drops below its acceptable range. The manual notes the Danfoss controller has low-voltage protection and will not output to the compressor when voltage is below 104V, so low voltage stops cooling.

Symptoms

• Display shows uLi with the alarm LED lit
• Compressor does not run or does not start
• Cabinet temperature rises while the alarm is active
• Lights or other loads on the same circuit may dim

Common causes

• Incoming line voltage below the unit's rated range (under 104V)
• Voltage drop from an overloaded or shared circuit
• Long or undersized supply wiring
• Building power supply problem

Diagnostic steps

1. 01

   Confirm the alarm

   Verify the Danfoss display reads uLi, the Line Voltage Too Low alarm.

2. 02

   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.

3. 03

   Check the dedicated circuit

   Confirm the unit is on its own dedicated line, as the manual requires, so other loads are not dragging the voltage down.

4. 04

   Understand the protection cutout

   Recall that the Danfoss controller will not output to the compressor below 104V, so cooling stays off until the voltage recovers.

5. 05

   Contact service

   The table directs contacting service for this alarm; call 888-994-7636 once a low-voltage condition is confirmed.

When to call a professional

Measuring supply voltage must be done by a qualified technician per the Danfoss table and the manual's warnings. Call a qualified electrician or a Randell Authorized Service Agent to confirm and correct low line voltage, since sustained low or high voltage can detrimentally affect operation and void warranty. Do not attempt live electrical readings yourself; reach service at 888-994-7636.