Service Disconnect Lug Tapping

[SparkyAdam]

Hello Forums,

We are building a new Electrical service on an existing building. The existing building was single phase, and they are moving to three phase 208. We are refeeding all the existing single phase panels and are adding a separate three phase panel for a few three phase loads they are adding. This is a total of four panels, three existing single phase and one new three phase panel. The building is becoming a small brewery and they have need of a few three phase circuits for brewery equipment.

The service is a 3-phase 400-amp overhead service, and the service disconnect we are installing is a DG325NRK (pictured below).



The disconnect pictured above needs to feed four separate disconnects and the lugs included are only rated for a max of 2x 300KCMIL wires max. I need to run four 250's out of this. There is not a lot of space on the load side for bigger lugs, so my solution is to use a 2-Sided Insulated Multi-Tap Connector (IPLD250-4 or similar).

What I am thinking of doing is running two wires from the included load side lugs, passing these two wires directly through the multi-tap connector above and taking those wires directly to two of the panels, then using the two open ports of the insulated lugs as a tap to feed the other two panel disconnects.


Something like this image.


This is a bit weird, and I'm not certain this would be code-compliant though I cannot think of what rule it would violate.

Any thoughts?

 

[infinity]

Personally I would install a wireway or a pull box below the disconnect and install the taps there. How long will the tap condcutors be?

 

[SparkyAdam]

Personally I would install a wireway or a pull box below the disconnect and install the taps there. How long will the tap condcutors be?

The panel disconnects are all directly adjacent to the service disconnect. The farthest one, as far as wire length is concerned, would probably be 15 feet or less.

 

[infinity]

The panel disconnects are all directly adjacent to the service disconnect. The farthest one, as far as wire length is concerned, would probably be 15 feet or less.

So you're good with the 25' tap rule. I wouldn't attempt to cram 4 of those connectors in that small gutter space within the 400 amp switch. Those lugs cannot be changed to accommodate 4 conductors?

 

[SparkyAdam]

So you're good with the 25' tap rule. I wouldn't attempt to cram 4 of those connectors in that small gutter space within the 400 amp switch. Those lugs cannot be changed to accommodate 4 conductors?

Standard four port lugs are too wide to fit here, I just had the thought of trying some stack panelboard lugs, likely the only thing that fits inside this housing. something like a PB4600 might work

 

[augie47]

Have you looked at leaving the existing as is and simply adding a disconnect for the 3 phase service ?

 

[SparkyAdam]

Have you looked at leaving the existing as is and simply adding a disconnect for the 3 phase service ?

We have to relocate the entire service as it is mounted on an exterior wall that is being added onto. In addition, the existing service is really old and needs to be replaced. Otherwise, this would have been the way to go.

 

[Tulsa Electrician]

Would that be 3 wires per line on the ungrounded and 4 wires on the netural.

Single phase:
A,B-N
C,A-N
B,C-N

Three phase:
A,B,C-N

 

[farmantenna]

This is a lug I've used

https://www.utilco.com/Utilco/ccrz__ProductDetails?sku=PTT2-250-ILSM-UTL&cclcl=en_US

 

[PCBelarge]

I am confused. You are installing a new service and trying to use a piece of equipment that seems to be inadequate. Why do you not just install a new service to meet your customer's needs??

 

[kwired]

Four 250's (assuming per phase) is going to be fun task just to get into the enclosure let alone terminate them in there.

As mentioned use a splice box or wireway and make taps in there. Connector like you had will work but needs to be six ports. Bring parallel conductors from the main disconnect to the two center ports and place outgoing taps in the out side ports.

 

[electrofelon]

Might end up being more expensive than a box and a bunch of Polaris connectors, but bussed gutters are real nice:

https://www.eaton.com/us/en-us/skuPage.R1048%20HDD.html

 

[jap]

Might end up being more expensive than a box and a bunch of Polaris connectors, but bussed gutters are real nice:

https://www.eaton.com/us/en-us/skuPage.R1048%20HDD.html

I was thinking the exact same thing.

Either that, or I'd be seriously considering using the disconnect to feed a 3r MLO MDP with some feeder breakers.

Jap>

 

[electrofelon]

I was thinking the exact same thing.

Either that, or I'd be seriously considering using the disconnect to feed a 3r MLO MDP with some feeder breakers.

Jap>

.....Or........ If you went that route, I might just get rid of that fused safety switch and put a 400A. MB with distribution breakers to feed the 4 panels. Lots of ways to do it.

 

[jap]

.....Or........ If you went that route, I might just get rid of that fused safety switch and put a 400A. MB with distribution breakers to feed the 4 panels. Lots of ways to do it.

One could go that route, but, I'm thinking lead times.
The lead time on a 400a Fused 3r disconnect will smoke the lead time on a 400a 3r Main Breaker Panel vs. a 400a MLO now days is the only reason I would stay away from the Main Breaker.

JAP>

 

[electrofelon]

One could go that route, but, I'm thinking lead times.
The lead time on a 400a Fused 3r disconnect will smoke the lead time on a 400a 3r Main Breaker Panel vs. a 400a MLO now days is the only reason I would stay away from the Main Breaker.

JAP>

I don't see why the lead time on a 400A MB would be any more than a MLO

 

[tom baker]

Might end up being more expensive than a box and a bunch of Polaris connectors, but bussed gutters are real nice:

https://www.eaton.com/us/en-us/skuPage.R1048%20HDD.html

I used a bussed gutter on a 400 amp CT service to 6 buildings worked great, can unbolt logs from buss if need to work downstream

 

[jap]

I don't see why the lead time on a 400A MB would be any more than a MLO

Because of the Main Breaker.

Jap.

 

[electrofelon]

Because of the Main Breaker.

Jap.

For the stuff I order, it wouldn't make any difference it would be a factory order either way. Maybe some larger supply houses stock some common configurations of panel boards, but I don't think any of the places I deal with would stock a 400 amp MLO.

 

[kwired]

I don't see why the lead time on a 400A MB would be any more than a MLO

I don't know about Eaton but if I were to use a Square D I-Line as the MDP I likely would be ordering components and field assembling them in most cases. Is faster as they come out of stock where if you order it assembled you have to wait for assembly.

If there still is supply chain issues, say the 400 amp breaker is currently hard to get, it holds up the final product whether field assembled or factory assembled.