Service disconnect

joec1824

Member
Location
Ohio
Occupation
Electrician
Can an over size breaker be used if it is only being used as a disconnecting means? I want to use a tap box with an 800 amp breaker to feed 4 gang stacked meter socket. The 4 gang socket will have 4 150 amp breakers.
 
Can an over size breaker be used if it is only being used as a disconnecting means? I want to use a tap box with an 800 amp breaker to feed 4 gang stacked meter socket. The 4 gang socket will have 4 150 amp breakers.
Sounds ok. Some may be concerned with the buss rating of the meter stack if it is under 800 amps, however there is no requirement to protect it at its rating by an OCPD unless specifically stated in the destructions.
 

Seven-Delta-FortyOne

Goin’ Down In Flames........
Location
Humboldt
Occupation
EC and GC
I having trouble understanding this scenario.

You’re feeding meters *after* a main disco?

What size is the service? What is the service disconnect rated for? Is the 800A breaker the Service Diaconnect?

S
 

jaggedben

Senior Member
Location
Northern California
Occupation
Solar and Energy Storage Installer
Can an over size breaker be used if it is only being used as a disconnecting means? I want to use a tap box with an 800 amp breaker to feed 4 gang stacked meter socket. The 4 gang socket will have 4 150 amp breakers.
What exactly makes the 800 amp breaker oversized? Just the combined ratings of the (4) 150A breakers? Or something else?
 

wwhitney

Senior Member
Location
Berkeley, CA
Occupation
Retired
As long as it protects the wire and equipment that's fine.
My take on the OP (which may be assuming too much) is that if everything upstream of the 150A breakers were rated for 800A, there would be no question. So my interpretation of the OP is that the question is this:

Suppose we have an install where overcurrent wise, everything is OK, but we are missing a needed disconnect. And now instead of installing say a knife-switch style disconnect, we install an enclosed OCPD. The rating of the OCPD is too high for it to be an appropriate overcurrent device, but we don't need an overcurrent device there. So we just want to use the OCPD as a switch. Is that OK?

Cheers, Wayne
 

acrwc10

Master Code Professional
Location
CA
Occupation
Building inspector
Yes an oversized breaker can be used as a disconnect. I used to do this all the time.
 
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