Shunt Trip Voltage Wiring

Status
Not open for further replies.
mshields

mshields

Senior Member
Location
Boston, MA
If I were to specify a distribution panelboard with a main breaker with 120V shunt trip, wired to an EPO, how would that control voltage normally get picked up. Would you need a 20A-1P breaker in the panel to be dedicated? How would that normally be accomplished?
 
I would get the control voltage from the shunt trip breaker. That way when the breaker opens there is no longer a voltage on the shunt trip coil. Many shunt-trip breakers can be damaged by a continuous voltage on the coil. I assume you are using an EPO momentary button so it shouldn't matter, but why use another breaker if you don't have to?

-Hal
 
hbiss said:
Sorry, missed that it was the main. In that case a dedicated breaker would be necessary.

-Hal
Click to expand...
Or tap the load side of the main breaker in the panel for the shunt coil (if permissible). And make sure you spec a coil that opens after activation.
 
mshields said:
But how would that be permissible to tap the bus without CB protection.
Click to expand...
My experience is with electric kitchen appliances, where this practice is fairly common. What exactly is the configuration we're talking about?
 
So I happen to be looking at a DP but one that is especially designed for an imaging machine. But I don't 'think it would matter if it were just a regular DP, say 225A MCB, 42 pole breakers. Assuming we're going to use line voltage to power the shunt trip, I think you'd need to dedicate a breaker from that panel OR conceivably from another But I don't know,
 
mshields said:
So I happen to be looking at a DP but one that is especially designed for an imaging machine. But I don't 'think it would matter if it were just a regular DP, say 225A MCB, 42 pole breakers. Assuming we're going to use line voltage to power the shunt trip, I think you'd need to dedicate a breaker from that panel OR conceivably from another But I don't know,
Click to expand...
The problem with dedicated breakers is, sometimes people turn them off. Now you don't have a shunt. Maybe you could put an in-line fuse on the hot to the shunt from the MCB?
 
gadfly56 said:
The problem with dedicated breakers is, sometimes people turn them off. Now you don't have a shunt. Maybe you could put an in-line fuse on the hot to the shunt from the MCB?
Click to expand...
Breaker locks solve that problem, some switch gear manufacturers have an option that does that, a switch with a fuse block factory prewired, and a terminal block for external switch connection.
 
Status
Not open for further replies.
Top