Getting creative with PVC connectors, no expansion fittings and wrong size feeders.

[69gp]

Walked through a site today and came across 2-800 amp panels that had 2-4" PVC connectors cut to within 1" of the hub side. Could not find anything in the manufactures site that says you cannot do that but one thing for sure I know someone won't be happy when they need to install a bunch of expansion fittings in all the conduits coming into the bottom of the panels. Its even harder when the wires are already installed. But then when you need to pull the wires out because its the wrong size I guess its not to bad. Prints call for 2 sets of 4-500MCM Copper conductors. Contractor pulled in 2 sets of 4-500 MCM Aluminum wires x 610' long runs. It will be interesting to see what he pulls in for the balance of the wiring for this project.

Now what would your words be if you were told you pulled in the wrong size wire. think it might go something like this.

Bill: hey Mark you pulled the wrong size feeders in.

Mark: get outta here.

Bill: no really.

Mark: what the @$%# are you *#*$#@$ kidding me

Bill: NO

 

[Canton]

Walked through a site today and came across 2-800 amp panels that had 2-4" PVC connectors cut to within 1" of the hub side. Could not find anything in the manufactures site that says you cannot do that but one thing for sure I know someone won't be happy when they need to install a bunch of expansion fittings in all the conduits coming into the bottom of the panels. Its even harder when the wires are already installed. But then when you need to pull the wires out because its the wrong size I guess its not to bad. Prints call for 2 sets of 4-500MCM Copper conductors. Contractor pulled in 2 sets of 4-500 MCM Aluminum wires x 610' long runs. It will be interesting to see what he pulls in for the balance of the wiring for this project.

Now what would your words be if you were told you pulled in the wrong size wire. think it might go something like this.

Bill: hey Mark you pulled the wrong size feeders in.

Mark: get outta here.

Bill: no really.

Mark: what the @$%# are you *#*$#@$ kidding me

Bill: NO

I'm sure cutting the connectors down violates its listing, you can cut the pipe but not the connector.

Why would they need expansion fittings for the conduits under the panels? Looks like one or two feet from the slap for an interior installation.

He put in Aluminum instead of Copper...you got stamped drawings? Whats the feeders for? Whats the calculated load? Looks like he did some value engineering.....looks good from my computer screen...:lol:

 

[kwired]

What good will an expansion fitting do here? Fitting itself will be longer then the exposed amount of raceway. I realize the straps possibly were there to hold raceways in place when backfill was installed, but the type used also does not allow for thermal expansion/contraction.

 

[Cow]

In the grand scheme, I think it's a minor issue at best, if at all. I always try to strap my pvc stubups just in case the backfill settles so they stay firmly seated in the MA. I also don't use expansion fittings for this type of install. As for the cut down connectors, I'm sure we've all done it, I have in a pinch. Obviously it's not ideal, and usually a result of having very little options. Sure, it may be a listing issue(I've never checked) but the bottom line is, in this instance, electrically it will still hold wiring just as well as an MA that hasn't been cut down.

When I have tight clearances like that I usually use running thread pvc. I think I've been told the rigid variety isn't legal though when I mentioned it at the supply house. I'm not sure on the pvc type, although I haven't been failed using it yet.

 

[69gp]

I'm sure cutting the connectors down violates its listing, you can cut the pipe but not the connector.

Why would they need expansion fittings for the conduits under the panels? Looks like one or two feet from the slap for an interior installation.

He put in Aluminum instead of Copper...you got stamped drawings? Whats the feeders for? Whats the calculated load? Looks like he did some value engineering.....looks good from my computer screen...:lol:

I would have used a threaded nipple with sealing locknuts on the outside. I did forget to mention that they were not installed.

The panel is outside and here in MA you can get some pretty good frost heaves. I have seen quite a few boxes and fittings destroyed when the earth starts moving.

I represent the owner and he bought a system that had all copper not a re-engineered job with aluminum. My comment to the owner would be to knock a few 100K off the job or have them change it to copper. Just for that one run is about an $80,000 change in price. Times another 8 runs of different feeder sizes ranging from 4/0 to 400 mcm and your talking a lot of money.
It would be one thing if the contractor approached us beforehand offering a savings but he did this on his own and now someone is going to pay.

 

[kwired]

I would have used a threaded nipple with sealing locknuts on the outside. I did forget to mention that they were not installed.

The panel is outside and here in MA you can get some pretty good frost heaves. I have seen quite a few boxes and fittings destroyed when the earth starts moving.

I represent the owner and he bought a system that had all copper not a re-engineered job with aluminum. My comment to the owner would be to knock a few 100K off the job or have them change it to copper. Just for that one run is about an $80,000 change in price. Times another 8 runs of different feeder sizes ranging from 4/0 to 400 mcm and your talking a lot of money.
It would be one thing if the contractor approached us beforehand offering a savings but he did this on his own and now someone is going to pay.

with frost heave you have to consider what is in the ground that is below frost line, and what will move and what shouldn't move based on what is extended below frost line.

If raceways are not below frost line but the structure the enclosure is attached to is then you likely see differential in movement between the two. If both are below or both are above they likely move together when they move.

 

[Cow]

I represent the owner and he bought a system that had all copper not a re-engineered job with aluminum. My comment to the owner would be to knock a few 100K off the job or have them change it to copper. Just for that one run is about an $80,000 change in price. Times another 8 runs of different feeder sizes ranging from 4/0 to 400 mcm and your talking a lot of money.
It would be one thing if the contractor approached us beforehand offering a savings but he did this on his own and now someone is going to pay.

Even if they are allowed to leave the aluminum, how will you correct the 620 amps of conductor being used for an 800 amp feeder? Replace the breakers/trip units?