FieldBench
Procedures
Electrical5 min

Short cycling

Five minutes on, two off is not a thermostat preference. Find the protection that is opening.

Clock it

  • Note run time, off time, and what drops first: contactor, board, or thermostat.
  • A 3–5 minute anti-short-cycle on the board is normal after a power blip. Repeating trips are not.

Usual suspects

  • HPS / LPS / freeze stat / high discharge. Read the code before you reset.
  • Oversized equipment or a tiny zone with no bypass.
  • Low voltage: long 18 AWG runs, shared transformers, weak common.
  • Hard-start / capacitor / voltage sag that lets the compressor kick out on internal overload.