Air conditioner electrical protection

[jose luis]

Hi, in my country most of the air conditioner installers are using 2 one phase breakers (110v) to protect the 220 v air conditioners, instead of use a two phase breaker in 220 v, is this practical correct, which are the risks of this action?, Thanks

 

[waross]

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
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"Why not the best?"
Jimmy Carter