Contactor controlled sub panel??

Status
Not open for further replies.
N

nizak

Senior Member
Would like some suggestions on controlling a 100amp single phase sub panel.
What I have is a sub panel that is set between the meter base and ATS of a residential service. This panel controls various loads that do not need to be operated in the event of back up power(hot tub, range, dryer,etc.)Due to the placement of the main service panel in a finished exterior wall, installation of load management relays was not practical, plus owner will be adding shop motor loads that shouldn't be connected to the back up supply either..Would like to have the panel (100A 2 pole breaker) de-energized when utility power is lost and re-energized when it resumes. Need something that does not require manual intervention since the system is intended to be fully automatic. What would be the best way to set up the contactor or other device so that the coil is not continuously energized? Seems to make more sense to only have it "holding" when the generator is running, would probably last much longer. Thanks.
 
If it is between the meter and the ATS, why don't you just leave it connected to the POCO wires, assuming that it is service rated and properly wired?
I do not see what a contactor would add to that.
If instead you want it disconnected from POCO whenever the generator is running even when POCO is up, (for test purposes?) then you do have a need for switching.


Tapatalk!
 
Last edited:
One of my concerns would be that at some point in the future, generator protected circuits could be accidently spliced into one of the sub panel circuits and feed back to the utility. Opening the breaker during back up power would eliminate that.
 
We use these breakers quite a bit in the entertainment industry for controlling remote loads:

http://www.lyntec.com/139-0390-00_BMB-MB_Breakers.pdf

Not sure if they offer 100A 2P version, but it might be worth calling them. Using something like this would also be contingent on your ATS control being able to source the necessary control signals.


SceneryDriver
 
nizak said:
One of my concerns would be that at some point in the future, generator protected circuits could be accidently spliced into one of the sub panel circuits and feed back to the utility. Opening the breaker during back up power would eliminate that.
Click to expand...

I am not all that worried about what someone might do. I cannot prevent someone from doing anything at some point down the road.
 
GoldDigger said:
If it is between the meter and the ATS, why don't you just leave it connected to the POCO wires, assuming that it is service rated and properly wired?
I do not see what a contactor would add to that.
If instead you want it disconnected from POCO whenever the generator is running even when POCO is up, (for test purposes?) then you do have a need for switching.


Tapatalk!
Click to expand...
This is the way everyone else does it. Existing panel is connected to the PoCo feed, a feeder from it feeds the "Normal" side of the ATS, the other side of the ATS comes from the Generator, the output of the ATS feeds a sub panel that has the feeder breakers for all of your critical loads.
 
Status
Not open for further replies.
Top