Need a single E-Stop to Shut Off Multiple Breakers at Once...Shunt Trip Breakers or Contactor?

dtown

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Location
Iowa
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Consultant
I have multiple boilers that require an E-Stop. My question is what is the best (safest) way to do this? Normally we just use an E-Stop that is interconnected to a shunt trip breaker for a single boiler.

Can I connect multiple shunt trip coils together? Or is using a contactor a better idea to control the circuits?
 
I have multiple boilers that require an E-Stop. My question is what is the best (safest) way to do this? Normally we just use an E-Stop that is interconnected to a shunt trip breaker for a single boiler.

Can I connect multiple shunt trip coils together? Or is using a contactor a better idea to control the circuits?
Yes, multiple shunt trip breakers with the same coil voltage can be connected together.
 
I have multiple boilers that require an E-Stop. My question is what is the best (safest) way to do this? Normally we just use an E-Stop that is interconnected to a shunt trip breaker for a single boiler.

Can I connect multiple shunt trip coils together? Or is using a contactor a better idea to control the circuits?
Do all boilers need to be disconnected by the E-Stop?
 
Shutting down the power to a boiler is not a good way to emergency stop it, it prevents the proper combustion chamber post purge, and heat exchanger purge, most boilers have a low voltage interlock circuit provided for safely shutting the boiler down. Some boiler flame supervision controls will reset a fault condition with a power cycle, which could also present a unsafe situation.
 
Shutting down the power to a boiler is not a good way to emergency stop it, it prevents the proper combustion chamber post purge, and heat exchanger purge, most boilers have a low voltage interlock circuit provided for safely shutting the boiler down. Some boiler flame supervision controls will reset a fault condition with a power cycle, which could also present a unsafe situation.
Ok I am working with some conflicting information. This was my first thought, I figure shutting off the gas supply would be a safer approach. Then the boiler should be able to finish its purge. However, this is what I was provided from a different manufacturer.
MMMDiagram.png
 
What do you have in mind a contractor panel and eveything landed on N/O?
All of the industrial e-stops that I have done have worked that way.

We even did a couple with 50+ relays to shut down all of the outputs of a DCS. Most if the outputs were relay outputs with separate power sources so relays using normally open contacts were installed between the DCS output and the field equipment. Since the coils were always energized, 4 pole relays were used. 3 poles controlled loads and the forth told us we had a relay failure.
 
What kind of boilers are they? Higher BTU burners have greater need for proper post operation purge which might be more applicable to say a steam producing boiler. If smaller boilers like used for producing hot water but no steam this may not be as critical to totally shut them down mid combustion cycle, particularly if only to be done in what should be a rare emergency situation.
 
What kind of boilers are they? Higher BTU burners have greater need for proper post operation purge which might be more applicable to say a steam producing boiler. If smaller boilers like used for producing hot water but no steam this may not be as critical to totally shut them down mid combustion cycle, particularly if only to be done in what should be a rare emergency situation.
If it needs a purge cycle the boiler control will cause that to happen when it restarts.

There is nothing wrong with an automatic restart. It's no different than if you have a power failure. You don't want to have to go reset them all after a power restoration.
 
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