Hello,
I am working on a large project where I have about 60 SCR controllers powered by single phase 208V and each 25A rated. They are all located in the same cabinet and wired from the same three phase power distribution. Each SCR wired as such: the SCR leg is fused with a semiconductor fuse and the reference line has a circuit breaker. The reference line is also connected to one side of the load and the SCR output to the other.
Each SCR powers a separate heater in a chamber that is in rough vacuum. There are several types of heater including graphite and others.
The problem is that occasionally I will get a short and that short would cause many other circuit breakers to trip in other circuits and also some fuses open. The short would also create issues in adjacent tools that are powered from a separate power drop. The short has not been explained yet either.
So far here is what I am going to do:
Add an isolation transformer to the heater/ scr cabinet.
Add ferrite cores to the SCR output wires.
Check all wiring for temperature created shorts.
My questions are:
Why are so many circuit breakers tripping from problem in just one circuit?
Why are much less fuses than circuit breakers opening under this event? (last time I had about 30 CBs tripping and only 5 fuses opening)
Why is this problem propagating to tools that only share the facilities electrical panel?
Any help would be greatly appreciated.
Regards,
I am working on a large project where I have about 60 SCR controllers powered by single phase 208V and each 25A rated. They are all located in the same cabinet and wired from the same three phase power distribution. Each SCR wired as such: the SCR leg is fused with a semiconductor fuse and the reference line has a circuit breaker. The reference line is also connected to one side of the load and the SCR output to the other.
Each SCR powers a separate heater in a chamber that is in rough vacuum. There are several types of heater including graphite and others.
The problem is that occasionally I will get a short and that short would cause many other circuit breakers to trip in other circuits and also some fuses open. The short would also create issues in adjacent tools that are powered from a separate power drop. The short has not been explained yet either.
So far here is what I am going to do:
Add an isolation transformer to the heater/ scr cabinet.
Add ferrite cores to the SCR output wires.
Check all wiring for temperature created shorts.
My questions are:
Why are so many circuit breakers tripping from problem in just one circuit?
Why are much less fuses than circuit breakers opening under this event? (last time I had about 30 CBs tripping and only 5 fuses opening)
Why is this problem propagating to tools that only share the facilities electrical panel?
Any help would be greatly appreciated.
Regards,