VAC stands for volts alternating current. It specifies that a voltage measurement or rating applies to a circuit where the current periodically reverses direction, as opposed to direct current. Equipment nameplates and multimeter dials use this abbreviation to clearly distinguish the AC rating from the DC rating, preventing catastrophic misapplication of switchgear or test probes.
Heard on the job
Set your meter to VAC before you probe those secondary terminals on the voltage transformer.
Also heard as
- volts AC