Carrier
PF
LockoutPF — input phase loss
Keypad example: PF. Missing or imbalanced incoming phase.
Walk PF in Diagnose
3 plates — walk the one on the cabinet
First check
1 Three legs at the disconnect and the contactor
On Carrier 48FC measure L1 L2 L3 at the disconnect and at the compressor contactor. A phase monitor trips on loss, imbalance, or reverse rotation. L1 L2 L3 at the drive and at the disconnect. Tight lugs.
Expect: All three legs, nameplate voltage ±10%, phase monitor closed.
The rest of the walkthrough is Diagnose.
On the plates
- L1 L2 L3 at the drive and at the disconnect. Tight lugs.
- A rooftop fuse that opened one leg looks like a dead motor until you read PF.
Plates that use PF
Same number, other makers
PF on Carrier is not the same code on these plates.