(Still learning) Just noticed that our electrician had used 8-gauge wire for a 240v 20amp circuit. Why would he do this? Couldn't he have just used 12 gauge? Is there a method to the madness?
There can be many reasons for using a larger than normal wire, including but not limited to.
- The person desinging the installation thinks that the breaker rating may need to be increased in the future.
- The circuit is unusually long and the larger wire is needed for volt drop reasons.
- Thermal insualtion or grouping concerns require the cable to be de-rated.
- The electrican was in a hurry and simply didn't have any smaller cable of the appropriate type on-hand.
- Someone simply made a mistake.