FieldBench
Lennox codes

Lennox

ov

Lockout

ov / OU — overvoltage

Keypad example: ov (Yaskawa) or OU. DC bus high. Usually regen on decel, not a new drive.

Walk ov in Diagnose

2 plates — walk the one on the cabinet

First check

1 Read the drive before you cycle power

On Lennox LGH photograph the VFD keypad or the unit-board fan alarm (OC, LU, OU, GF, OH, limp). Power-cycle wipes what you needed. ov on shutdown = decel too fast; lengthen decel.

Expect: Live drive code written down. Line voltage at L1/L2/L3 of the drive.

The rest of the walkthrough is Diagnose.

On the plates

  • ov on shutdown = decel too fast; lengthen decel.
  • Incoming voltage high or a utility swell. Measure line first.

Plates that use ov

Same number, other makers

ov on Lennox is not the same code on these plates.