46 Brown-out (low voltage)

What the control is telling you

Single-stage boards (and C4A3/CXA6 board): 24 V control voltage below 15.5 V for 4 s; runs again at 17.5 V or more. Two-stage boards: line voltage below 187 V for 4 s; runs again above 190 V.

Applies to: KeepRite *SA5/*SA6 AC and *SH4/*SH5/*SH6 HP single-stage communicating; *CA7/*CA9 AC and *CH6/*CH9 HP two-stage communicating

Likely causes

• Weak or overloaded 24 V transformer
• Low utility line voltage
• Loose power or control wiring

Test and repair steps

1. Single-stage / C4A3-CXA6 measure 24 V at the outdoor board - it should be 18-30 V. Check transformer size and load.
2. Two-stage measure line voltage at the contactor under load.
3. Tighten loose connections and recheck.

Models that show this code

11 models in KeepRite *SA/*SH Single-Stage Communicating, KeepRite *CA/*CH Two-Stage Communicating

Other codes on the same units

• 25 Model plug missing or invalid
• 31 High pressure switch open
• 32 Low pressure switch open
• 45 Outdoor control board failure
• 47 No 230 V at the unit
• 53 Outdoor air temperature sensor fault
• 55 Outdoor coil sensor fault
• 56 Air and coil sensors disagree