Isolation Transformer vs. 3-Phase Breaker

[pyro214]

I recently found a breaker on a three-phase system where if one phase trips, the other two phases won't trip. I was told by someone, "There is an isolation transformer connected to the circuit breaker which eliminates the risk of one phase being live if any of the phases trip"

Does this make sense to any of you?

 

[dpc]

No. For a three-phase feeder, all three poles need to open.

 

[pyro214]

That is my thought as well however do you have any idea why they would make that statement about the isolation transformer for a 3-wire 3-phase system?

 

[jraef]

Because they have no idea what they are talking about?

From my experience some people think transformers are mystical devices to which they proscribe all sorts of properties that defy the laws of physics.

"Will work for (the memory of) salami"

 

[SceneryDriver]

Trip one of the three phases, and then tell that person to go lick the secondary conductors. Tell us what happens

SceneryDriver

 

[pyro214]

Will do. At least one of us will learn a lesson