What is it?

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ptonsparky

ptonsparky

Tom
Location
NE (9.06 miles @5.9 Degrees from Winged Horses)
Occupation
EC - retired
Looked at a project with another EC in the area. The project is to large for him to tackle on his own.

Power comes from a CT cabinet to a 400 amp non fused disconnect on the outside of the building then on in to a 400 amp loadcenter with main breaker, or so I was told. The neutral is not bonded at the disconnect but it does have a green wire bonded to it and passing on through.

What is the non fused disconnect? A junction box with a handle?
 
Where is the load center located in relation to the non-fused disconnect?

I see a couple of possible issues....what is the available fault current at the disconnect? Most unfused disconnects have a SCCR of 10,000?

It is my opinion that the disconnect is the service disconnect and 230.91 requires the service OCPD to be immediately adjacent to the disconnect.
 
I'd make sure there was proper grounding, vefify the size of the green wire was of sufficient size, put the bonding screw in to bond the Neutral Bar to the can and call it a Non-Fused Service Disconnect.


JAP>
 
don_resqcapt19 said:
Where is the load center located in relation to the non-fused disconnect?

It is my opinion that the disconnect is the service disconnect and 230.91 requires the service OCPD to be immediately adjacent to the disconnect.
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jap said:
I'd make sure there was proper grounding, vefify the size of the green wire was of sufficient size, put the bonding screw in to bond the Neutral Bar to the can and call it a Non-Fused Service Disconnect.

JAP>
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Yep, but as Don points out if the main breaker is on the other side of the wall it's not compliant and all bets are off.
And Ptonsparky says it went into a 400 amp main breaker panel or so he was told so it sounds like the two are not side by side.
 
Big picture - what is the job?
There are a gazillion instances where the NEC does not apply.
Sounds like someone wanted to have the ability to disconnect the service entrance.
 
Let's first establish whether this is a service entrance or a separate building feeder. With the CT's there, more likely a service. Want to make certain...


A feeder to a separate building is required to have a disconnecting means at the building entrance, but not with integral or immediately adjacent OCP.
 
Smart $ said:
Let's first establish whether this is a service entrance or a separate building feeder. With the CT's there, more likely a service. Want to make certain...


A feeder to a separate building is required to have a disconnecting means at the building entrance, but not with integral or immediately adjacent OCP.
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It would be rare for the conductors to a second building to be coming from a CT cabinet.
 
The other EC saw the inside of the building when he did a walk through with the GC.

The project will be an addition approx 150 North of the disconnect and CT cabinet. The inside of the existing building is totally finished and is used for kidney dialysis treatments. A 200 amp panel is to be installed in the addition.

Our first thoughts were an outside feeder to the addition from the load side of the 400 amp disconnect. No fuses to me means it is not the SE. A tap from it would mean our 200 would become another Service Entrance 150' away. Not good. The floating neutral in the disconnect gives another hint that it was not intended to be the SE.

I can see its use allowing work on the 400 amp load center without calling for POCO disconnect at the transformer. That padmount most likely feeds several other businesses in the area.
 
I don't know what it was intended to be, but it is, in my opinion, the service disconnect.
I would recommend the installation of a distribution panel next to the existing disconnect. It can be a MLO panel as long as you install six or less breakers.
 
ptonsparky said:
.... No fuses to me means it is not the SE. ...
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I think you mean Service Disconnecting Means (SDM). The disconnect is inline with the SE. Not permitted under Code or a vague interpretation of 220.82, possibly required by POCO, to prevent feedback in case they have to work on the SE.
 
Weeelll, we went into the building with city inspector and did some digging. The non fused disconnect turned out to be a generator disconnecting means prior to it hitting the ATS inside the building. A label would have been nice. The other EC knew there was a gen set on site. He failed to mention it. The CI was not real pleased with the install but it was done before he was hired on. It all makes sense, but it is not going to be an easy project to add an additional 200 amp panel. To much crowded in one location.
 
ptonsparky said:
Weeelll, we went into the building with city inspector and did some digging. The non fused disconnect turned out to be a generator disconnecting means prior to it hitting the ATS inside the building. A label would have been nice. The other EC knew there was a gen set on site. He failed to mention it. The CI was not real pleased with the install but it was done before he was hired on. It all makes sense, but it is not going to be an easy project to add an additional 200 amp panel. To much crowded in one location.
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If that's the case why was the disconnect even piped into the CT Cabinet?


JAP>
 
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