3ph delta star switch, delta tripping fuse

[D Skelton]

Jeez, this saw sounds like a death trap! No no-volt protection, no OL protection, manual changeover without interlock, not rotation tested before running!

Run away!

 

[T0RN4D0]

Circular saws are death traps if you don't use them carefully. And no amount of protection (especially OL) can help you there.

 

[Deleted member 72666]

The whole unit was home made. Regulations are not a problem because there basically are none when it comes to what you're using at home. And yes, there is no no-volt release and no motor protection. I think it might be worth adding it.


I didn't check the current on all phases, would be easy enough to do. Did check the voltage on all three phases (only had a DMM with me) on the motor clamps and that was fine, but i guess that doesn't matter if there's a problem with one of the windings.

Is it possible that the breaker is so close to the limit when starting it needs a few seconds to "cool off" before its able to go through another over-amp jolt when switching to delta?

I suspected as much (see post #24). But my advise to you would be: do the right thing, either scrap this monstrosity altogether or spend a little time and money and make this right with ALL the safety features in place.
As for the motor check and compare between windings for resistance and windings to earth for leakage.