Service Conductors in and out of building for ATS

xguard

Senior Member
Location
Baton Rouge, LA
We have an ATS we are replacing. It wasn't service rated, it's too small, and many other problems. Our service is from a pad mount utility transformer outside the building. The service conductors come underground into the bottom of the switch board. Currently, the service conductors enter the bottom of the switchboard, exit the side of the switchboard, pass through a stairwell (this is another issue) going back outside to an ATS, then re-enter the building back through the stairwell and back through the side of the switchboard finally landing on the switchboard terminals. Whew that was a mouth-full.

If the service conductors were going to another building and passing through this one, this would be a problem (NEC 230.3). But what about going back out a building to an ATS?

Is there another article I'm missing that would not allow us to duplicate this method of entering the switchboard from underground and exiting to the ATS?
 

jap

Senior Member
It sounds to me like the service conductors landed in the switchboard originally.

Then,

They added the generator and transfer switch after the fact.

That's when they took the Service Conductors off of the switchboard, extended them outside to the Transfer Switch, and then back inside to the Switchboard to re-terminate where they were originally.

At least that's the picture I'm coming up with.

JAP>
 

xguard

Senior Member
Location
Baton Rouge, LA
It sounds to me like the service conductors landed in the switchboard originally.

Then,

They added the generator and transfer switch after the fact.

That's when they took the Service Conductors off of the switchboard, extended them outside to the Transfer Switch, and then back inside to the Switchboard to re-terminate where they were originally.

At least that's the picture I'm coming up with.

JAP>
Exactly. Yes the switchboard was the service disconnect.
 

jap

Senior Member
I wouldn't think this scenario would qualify the Service Disconnect as being at or near the closest point of entry to the structure.

JAP>
 

hbiss

EC, Westchester, New York NEC: 2014
Location
Hawthorne, New York NEC: 2014
Occupation
EC
It sounds to me like the service conductors landed in the switchboard originally.

Then,

They added the generator and transfer switch after the fact.

That's when they took the Service Conductors off of the switchboard, extended them outside to the Transfer Switch, and then back inside to the Switchboard to re-terminate where they were originally.
What kind of switchboard, how big of a service?

Ideally you need to add a main breaker in there like was there originally. Then out to the ATS and back as it is now.

-Hal
 

jap

Senior Member
Why are you not feeding the ATS from the switchboard? What is the rating of the switchboard, ATS, etc.? Does the switchboard have a main breaker?
None of that matters because the Generator and ATS he has is feeding the Switchboard he's talking about.

The Service Conductors coming in do not terminate on the Switchboard. They terminate on the outside ATS.
They are using the indoor Switchboard as a raceway to get to outside ATS that's feeding that Switchboard.

Without the ATS being Service Entrance Rated, then he technically has Service Conductors passing through his indoor Switchboard, back to the outside of the building, through the outside ATS and back into the building where they terminate on the Switchboard being used as the raceway.

JAP>
 

xguard

Senior Member
Location
Baton Rouge, LA
Why are you not feeding the ATS from the switchboard? What is the rating of the switchboard, ATS, etc.? Does the switchboard have a main breaker?
I don't see a way to feed the ATS from the switchboard. The switchboard is rated 1600 amps. The switchboard does not have a main breaker. It has a 1600 amp electric trip bolted pressure switch and fuses.

The highest load recorded by the utility company was 713 amps. Based on 220.87 I got 713 amps x 1.25 = 892 amps.

The current plan is to install a 1000 amp service rated transfer switch outside of this building. Dig up and intercept the existing conduits from the utility and extend them to the ATS. Then use the existing conduits to feed back into the building to the switchboard.

I don't see a way to come off the load side of the fuses and disconnect in the switchboard to feed to the ATS. Maybe there is one. I don't have any drawings on the switchboard. I contacted square D and they don't have any either. It was installed in 1980 if that helps.
 

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jap

Senior Member
Then the conductors to the transfer switch are not service conductors.
Without any disconnect or overcurrent protection from the load side of the Utility Transformer to the line side of the Non-Service rated transfer switch on the outside of the building those conductors would still Service Conductors.

They simply pass through the indoor Switchboard to get there.


JAP>
 

ActionDave

Moderator
Staff member
Location
Durango, CO, 10 h 20 min without traffic from wing
Occupation
wire pulling grunt
Without any disconnect or overcurrent protection from the load side of the Utility Transformer to the line side of the Non-Service rated transfer switch on the outside of the building those conductors would still Service Conductors.

They simply pass through the indoor Switchboard to get there.


JAP>
I understand now. I thought there would have been a main in the switchboard and then load side wires out to the ATS.
 

jap

Senior Member
The current plan is to install a 1000 amp service rated transfer switch outside of this building. Dig up and intercept the existing conduits from the utility and extend them to the ATS. Then use the existing conduits to feed back into the building to the switchboard..
That would be the best be.

[/QUOTE] I don't see a way to come off the load side of the fuses and disconnect in the switchboard to feed to the ATS. Maybe there is one. I don't have any drawings on the switchboard. I contacted square D and they don't have any either. It was installed in 1980 if that helps.[/QUOTE]

Think about how dangerous that setup would be.

If you uncoupled the main from the buss in the Switchboard and ran load side conductors out to the ATS and back, The main would work as a disconnect for the panel when on utility power, but, would not serve to disconnect the power to the Switchboard when the X-fr Switch was on generator power.

That's just a bad setup all the way around in my book.

JAP>
 

xguard

Senior Member
Location
Baton Rouge, LA
That would be the best be.
I don't see a way to come off the load side of the fuses and disconnect in the switchboard to feed to the ATS. Maybe there is one. I don't have any drawings on the switchboard. I contacted square D and they don't have any either. It was installed in 1980 if that helps.[/QUOTE]

Think about how dangerous that setup would be.

If you uncoupled the main from the buss in the Switchboard and ran load side conductors out to the ATS and back, The main would work as a disconnect for the panel when on utility power, but, would not serve to disconnect the power to the Switchboard when the X-fr Switch was on generator power.

That's just a bad setup all the way around in my book.

JAP>[/QUOTE]

Thank you for the feedback!!!
 
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