generator transfer switch and main service panel

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dec

dec

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I would like to install a generator transfer switch next to my service panel. I want to disconnect the service conductors from the main breaker and run them thru a short nipple to the transfer switch, then from the transfer switch back to the main service panel breaker. This would mean using the existing service panel as a feed thru to the transfer switch and then back to the main in the service panel. Is this permissible by the NEC ?
 
What you are talking about is not a "feed through", that would mean using lugs on the buss in the panel to feed another panel.

What you would have is a transfer switch fed after the service disconnect. It is not an NEC violation. It's the way I prefer to wire transfer switches.
 
ActionDave said:
What you would have is a transfer switch fed after the service disconnect. It is not an NEC violation. It's the way I prefer to wire transfer switches.
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Sounds to me like the transfer switch is technically before the service disconnect in the panel.
 
I think maybe I gave the wrong description of my set up. I have a 30+ circuit breaker panel with a main circuit breaker. The service conductors from the outdoor meter can enter the top of my circuit breaker panel which is located in my basement. I want to locate the generator transfer switch right next to my circuit breaker panel. I would like to disconnect the incoming service conductors from my main breaker in the circuit breaker panel and re-route them thru a nipple to the generator transfer switch. From the transfer switch....I would run to the main circuit breaker in my panel. So....the incoming line would pass thru my main circuit breaker panel, connect to the transfer switch, then run back to the main circuit breaker in my circuit breaker panel.
 
dec said:
I think maybe I gave the wrong description of my set up. I have a 30+ circuit breaker panel with a main circuit breaker. The service conductors from the outdoor meter can enter the top of my circuit breaker panel which is located in my basement. I want to locate the generator transfer switch right next to my circuit breaker panel. I would like to disconnect the incoming service conductors from my main breaker in the circuit breaker panel and re-route them thru a nipple to the generator transfer switch. From the transfer switch....I would run to the main circuit breaker in my panel. So....the incoming line would pass thru my main circuit breaker panel, connect to the transfer switch, then run back to the main circuit breaker in my circuit breaker panel.
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In that case you would need a service rated transfer switch and your main breaker panel would become a sub panel.
 
I've never seen anyone leave SE conductors long enough that they could be re-routed to another panel!

Also, wouldn't that violate the rule of not having any conductors beside the service conductors in a raceway? The way I see it he would have the main service wires then a feeder set in the same raceway.
 
ActionDave said:
In that case you would need a service rated transfer switch and your main breaker panel would become a sub panel.
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Along with relocating the GECs to the TS and making sure the EGCs and neutrals are separated, with the neutrals isolated, and, technically speaking, making sure the major-appliance circuits are 4-wire supplied and wired.
 
Little Bill said:
I've never seen anyone leave SE conductors long enough that they could be re-routed to another panel!
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No, he'd need to use splices.

Also, wouldn't that violate the rule of not having any conductors beside the service conductors in a raceway? The way I see it he would have the main service wires then a feeder set in the same raceway.
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As well as in the panel itself.
 
The service conductors would land on a properly sized transfer switch and would not share the raceway with the conductors going back to the main breaker. All service conductors and the GEC would be new (no splices).
 
dec said:
The service conductors would land on a properly sized transfer switch and would not share the raceway with the conductors going back to the main breaker.
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You're contradicting yourself:
dec said:
I want to disconnect the service conductors from the main breaker and run them thru a short nipple to the transfer switch, then from the transfer switch back to the main service panel breaker.
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. . . unless you're talking about two nipples.
 
Sounds like two nipples to me, it's code compliant if he uses two nipples and a service rated transfer switch.
 
dec said:
So....the incoming line would pass thru my main circuit breaker panel, connect to the transfer switch, then run back to the main circuit breaker in my circuit breaker panel.
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IMHO, that would not be a safe installation. You are splicing “unprotected” service wires inside a MBP, through a nipple to the Xfer breaker and then back to the MBP. I would install a new piece of SE cable (if that’s what you are using) from the meter can to the xfer panel and then 3 wires + EGC back to the MBP. The neutrals in the MBP now have to float so... you’ll have to re-route the rod and water main grounds to the Xfer panel.
 
One alternative would be to install a main disconnect between the meter and the existing panel, rendering everything inside as feeders, and a single nipple could be used. This means relocating the GECs to that new disco, and not requiring a service-rated ATS. The ground/neutral separation is required either way.
 
No splicing.....new conductors throughout including the GEC and yes two separate nipples including bond bushings.
 
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