Switchboards

mannyb

Senior Member
We have a 2500a SwitchBoard to be installed. The building is tilt wall and is existing and the conduit runs cant be feed under ground. We will need to run conduit thru the wall to Switchboard. The Switchboard will sit against the wall and back side will sit against the wall on backside. The only part i am worried is that the instructions request we not penetrate side panels and we cant enter bottom because its an existing building. i guess we could enter top but the drawings suggest 6-4'' conduits for parallel feeds to Switchboard and that would take most of my space for feeder conduits. I hope I explained it enough to get idea of my situation. I am basically looking to hear if anyone has any suggestions on how to feed Switchboard without entering thru bottom.
 

Jraef

Moderator
Staff member
I would add a pull section to the side. So you would bring your incoming cables into the top of the pull section, then loop down and connect to the bus or main from the bottom. That leaves the entire top of the board for your feeder cables / conduits.

Don't judge the picture here, I just pulled something from the web to illustrate the concept. I have no idea what all that other stuff is in there.
15a_RHunterPH6.jpg
 

electrofelon

Senior Member
I'll be the one to say it: just come in the side. It's done 37 times every day. Come into the back of a pull box nippled into the side of the swbd.
 

infinity

Moderator
Staff member
You can add a crown box to the top of the switchboard and come into the side of that with your 6 conduits. Just make sure that the board is designed to be top fed.
 

mannyb

Senior Member
I'll be the one to say it: just come in the side. It's done 37 times every day. Come into the back of a pull box nippled into the side of the swbd.
That was my plan but With 6-4'' conduits it will look pretty beefy. I guess I dont have a choice we cant trench under building.
 

mannyb

Senior Member
how would something like that look. Is this something that can be ordered. i just need it to stab to outside of building so I can bring conduit/wire to that area and I dont have to run 6-4'' conduits for 2500a feed. thanks for any help
 

don_resqcapt19

Moderator
Staff member
I would never consider bus duct where any part of the bus duct run would be outside. I worked in a plant for a large plastics manufacturer and they had repeated outside bus duct failures at the plant I worked in and other plants. Even though the bus duct was rated for outside locations, over time water gets into the connections and can result in failure. They removed all of their outside bus duct and replaced it with cable bus.
 

publicgood

Senior Member
I would never consider bus duct where any part of the bus duct run would be outside. I worked in a plant for a large plastics manufacturer and they had repeated outside bus duct failures at the plant I worked in and other plants. Even though the bus duct was rated for outside locations, over time water gets into the connections and can result in failure. They removed all of their outside bus duct and replaced it with cable bus.
Do you know if they installed heaters within the bus duct? Took precautions (and followed code) by utilizing vapor barriers at entrances of buildings? Derate for ambient? IR connections periodically?

There are several factors that need to be done correctly to achieve reliability.
 

infinity

Moderator
Staff member
Do you know if they installed heaters within the bus duct? Took precautions (and followed code) by utilizing vapor barriers at entrances of buildings? Derate for ambient? IR connections periodically?

There are several factors that need to be done correctly to achieve reliability.
All of that makes it even less desirable to use bus duct to replace just 6 conduits.
 

don_resqcapt19

Moderator
Staff member
Do you know if they installed heaters within the bus duct? Took precautions (and followed code) by utilizing vapor barriers at entrances of buildings? Derate for ambient? IR connections periodically?

There are several factors that need to be done correctly to achieve reliability.
Yes, all of that was done, with the exception of bus duct heaters. They were not specified in the manufacturer's instructions for exterior installations.
 

mannyb

Senior Member
I'll be the one to say it: just come in the side. It's done 37 times every day. Come into the back of a pull box nippled into the side of the swbd.
My problem is that building is existing. There is an existing service just outside wall where the new 2500a SB will sit. unfortunately i will need togo above existing service outiside then back down to make up feeds on inside at bottom of SB to breaker. I looked into the added pull box from another post but it will take to long to get parts. I was looking at maybe a nema 1 gutter on its side then penetrate top and bottom like an LB. What you guys think. I am just looking for alternative route.
 
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