2000 Amp Switchboard

[dav5y]

Hello All,

I'm an electrical engineer and I'm designing for a new generator and ATS installation. Currently there is a 1600A (main switch), 480V switchboard feeding multiple bkr's. For the ATS I was planning on removing the current connection from the main switch (load side) to the bus and re-route, with cable, from the main switch to the normal side of the ATS. Bringing the load side back to the bus. Is it possible to reconfigure the load side of the main switch to do this, or an easier way ???? Any advice or ideas would be helpful ....

 

[charlie b]

I am unfamiliar with the use of the phrase "main switch" in this context. Is this a "switch" located outside switchboard enclosure? Is it more properly called a "breaker," and is it located within and connected to the main bus within the enclosure? If this thing is inside the enclosure, I don't think you will want to alter the way it is connected. You would have to get the manufacturer to buy into your proposed changes, and I doubt they would agree.

 

[Shoe]

Is this a single assembly connected by bussing? If you need to "break" the bussing within, I have done this before. But best to have a contractor or field-technician for the switchboard manufacturer to review and make sure it can be done. You'll also need to review available space for cabling and termination to the existing enclosure.

Actually, my application would have been very similar to the one you describe, which added a generator back up the load for that entire assembly.

 

[dav5y]

The main ckt breaker is in the same enlosure as the switchboard. It's the ct, main breaker then to mutiple breakers off the bus.

 

[dav5y]

How do you "break" the bus Mr. Shoe ?

 

[texie]

The main ckt breaker is in the same enlosure as the switchboard. It's the ct, main breaker then to mutiple breakers off the bus.

As others have mentioned, this would require the manufacturers blessing due to NRTL listing issues. Assuming they would go along this would still probably require a field evaluation by an NRTL. Given the size though it may be worth exploring with the manufacturer.

 

[dav5y]

It's a Square D switchboard. I'm assuming if I talk to them they will tell me im negating the UL Listing, if I do it this way. I have another way, but its expensive.

 

[jim dungar]

It's a Square D switchboard. I'm assuming if I talk to them they will tell me im negating the UL Listing, if I do it this way. I have another way, but its expensive.

Of course you are probably impacting the UL Listing - you are definitely changing the equipment from the way is was shipped by the factory.

Have you considered hiring Square D to come in and modify the bussing?

Without making any other changes, I do not believe you will have enough room in the existing structure for two sets of lugs for 1600A conductors.

 

[dav5y]

I'm the electrical engineer Jim. I could specify the contractor to hire "square d" to modify the bus. I did not know that was possible or even an option. I did call square d and that got me some info. I think im going to have to call a local switchboard manufacturer.

 

[Shoe]

How do you "break" the bus Mr. Shoe ?

Break is maybe a poor choice of words. I intended to imply that the section of bus connecting the main section to the remainder of the switchboard would be split or isolated.

 

[electrofelon]

I wonder if it would be possible to remove the main breaker, add a lug kit to basically turn it into a MLO panelboard, and buy a new enclosure for that main breaker? You could talk to a square D rep to see if the needed parts are available. I am doing a similar thing with some (much smaller) gear. I am pulling out some main breakers that are not needed from some "sub panels", replacing with a lug kit, and using these breakers in the new service equipment. It is saving the owner $1600 off the new service gear for an hour of work.

 

[electrofelon]

...And just to be sure, the ATS is not service rated?

 

[masterinbama]

I once had Square D build a switchgear section with a 1600 amp ATS built into it. We removed the first switchboard section from the array and moved it to the end, then put our new ATS section back into it's place. Made for a neat installation