Tek-Tips is the largest IT community on the Internet today!
Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!
-
Congratulations MintJulep on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!
Air conditioner electrical protection
- Thread starter jose luis
- Start date
- Moderator
- #2
We used to use two breakers with a handle tie.
The reason for a two pole breaker is mostly but not all a matter of safety.
With two single pole breakers an overload or fault may leave one breaker still energized.
This may pose a hazard to a repairman who doesn't realise that one line to the inoperative A/C is still hot.
There may be a rare instance where a winding goes to ground internally and initially trips only one breaker leaving the motor energized by the other line with the return path through the ground fault. This will in most instances sooner or later trip the second breaker.
Bill
--------------------
"Why not the best?"
Jimmy Carter
The reason for a two pole breaker is mostly but not all a matter of safety.
With two single pole breakers an overload or fault may leave one breaker still energized.
This may pose a hazard to a repairman who doesn't realise that one line to the inoperative A/C is still hot.
There may be a rare instance where a winding goes to ground internally and initially trips only one breaker leaving the motor energized by the other line with the return path through the ground fault. This will in most instances sooner or later trip the second breaker.
Bill
--------------------
"Why not the best?"
Jimmy Carter
- Status
Similar threads
- Question
- Question