Applicable Systems
RTAC 200

Symptoms

Undervoltage fault. The supply voltage has dropped below the minimum rated value.

Possible Causes

  • Power supply voltage sag or brownout
  • Undersized wiring causing voltage drop

Troubleshooting Steps

  1. Step 1: Check the supply voltage at the unit
    Voltage is below the rated minimum
  2. Step 2: Verify the power supply capacity and wire size
    Supply is undersized or wiring is too small

How to Reset

To reset: Restore the voltage to within range, then reset the controller.

Source: Trane HVAC Service Manual, Trane Inc.

Category: HVAC Residential