Overview:
Condensate overflow is an optional feature that helps prevent condensate from overflowing outside of the unit. The switch is installed in the condensate drain pan of the air-to-refrigerant coil near the outlet. Condensate overflow protection for the waterside economizer coil is field provided.
When condensate reaches the trip point, a general alarm is initiated and the fan, unit water valves (if present), and compressor(s) are disabled. The unit will remain in a halted state until the condensation returns to a normal level, and the switch returns to its normally closed state. The controller's condensate overflow diagnostic must be manually reset to clear the diagnostic and restart the unit. A reset can be performed by toggling the Reset Diagnostic binary value or by cycling power.
Troubleshooting:
- The condensate switch is normally closed with a dry pan. Disconnect the wires from the switch and test continuity while moving the switch to ensure it opens and closes as expected.
- The condensate switch is wired in series with a relay. Confirm the relay coil is getting 24-27vac.
- Unwire the relay and check continuity on the coil to ensure it's not open.
- The relay contacts initiate an alarm at the control. The unit diagram shows the contacts normally open, but when power is applied to the unit with no condensate is present, the contacts should be closed. Confirm contact closure by removing the wires and testing continuity.
- Confirm you're getting 5vdc on P1. The pin circled in green is 5vdc (+) and the opposite pin is (-). You should read 5vdc across the two outer pins of P1.
- Blow the condensate drain line with compressed air or nitrogen.
- Disassemble fittings as needed to restore flow.
- Pour water in the pan and verify flow at the building drain.
- Ensure the trap is primmed. A dry condensate trap can cause air to be sucked into the condensate drain tubing leading to switch flutter and a false condensate overflow trip.
| Control Type: | Condensate Switch and Relay Wiring Example: | Condensate Overflow Input Location: |
| UC400 & Symbio 500 | ||
| Symbio 400-B |
WARNING:
Information in this article is intended for use by individuals possessing adequate backgrounds of electrical and mechanical experience and who comply with all federal, state, and local laws, rules, orders, or regulations related to the installation, service, or repair of a heating or central air conditioning product. Any attempt to install, service, or repair a heating or central air conditioning product may result in personal injury and/or property damage. The manufacturer or seller cannot be responsible for the interpretation of the information contained herein, nor can it assume any liability in connection with its use.