PVC into bottom of panel

Status
Not open for further replies.
I build Modular homes I need a way to easily install the Feeders into the panel from the meter main after the house is assembled I thought pvc? There was a question of not being able to ground the PVC. Is this legal?
 
Re: PVC into bottom of panel

Are you saying that you think you need to ground the PVC? There is nothing to say that non-metalic anythings need to be grounded.

Or are you saying that there will be no metal conduit to use as a ground? A full size ground wire would have to be pulled in the conduit at the time the house was wired in the field.
 
Re: PVC into bottom of panel

goingtohurt, you're going to need to go get some PVC bonding clamps, and bond both ends of the conduit. When you get to the supply house, be sure to speak up and stand your ground, because sometimes they're hard to come by and the parts guy is probably just holding out for his regular customers.

I couldn't resist.

I believe it's common practice to stub out the bottom of the panel with PVC. When the home is installed, the electrician will make it a continuous run out to the service.

Unless you're installing the metermain at the factory, which doesn't seem like a very good idea. Without knowing the final destination, your meter could end up on the wrong side of the house; or the home could end up on rural property where the meter is on a pole and outbuildings and whatnot would be more easily served from a multiple space disconnect on the home.
 
Re: PVC into bottom of panel

This is going to hurt a little but I can?t help it. These homes that you are building, at least in my state, will require a third party listing as well as a HUD stamp. These people will keep you straight with the way to build these homes and the equipment that is installed.

These listing and labels don't come cheap.
:)
 
Re: PVC into bottom of panel

I realize that it is very hard to ground PVC. Thanks for the first year cubby joke. I've just never seen it done and I cant find any code reference to say otherwise. It just seems hokey to me. It was my idea to leave a # 12 from the panel to the crawler until the assembly and use the 12 as a pull string so to speak pulling the feeder in and it would be as if I had done it on site. I do know the exact location on every house as to where the meter is going or even if the meter is existing then I will just stub out. we don't have a hud stamp in our state.
 
Re: PVC into bottom of panel

The big o sells bags of earth ground don`t they ?? :D Oh sorry my bad that`s bags of soil not NEC Listed :p
Do you do your own hook ups or does a licenced EC do it?
 
Re: PVC into bottom of panel

Originally posted by jwelectric:
These homes that you are building, at least in my state, will require a third party listing as well as a HUD stamp.
Mike are you sure about that?

I know you posted some NC rules about 3rd party listing but will that really apply to HUD stamped equipment?

I thought that the HUD stamp basically meant the States have been told by the Feds they have to accept it.

Really out of my area of work, just wondering.

Bob
 
Re: PVC into bottom of panel

Originally posted by goingtohurt:
I realize that it is very hard to ground PVC. Thanks for the first year cubby joke.
Do what I can to help. :)

It was my idea to leave a # 12 from the panel to the crawler until the assembly and use the 12 as a pull string so to speak pulling the feeder in and it would be as if I had done it on site.
How will you clamp the SER to the panel for strain relief? Otherwise, doesn't sound like a bad idea.

I do know the exact location on every house...
How? I'm curious (not so much "doubting you").
 
Re: PVC into bottom of panel

As someone who routinely connects the services and does the site work on modular homes, I welcome this opportunity to offer you some first hand feedback on their installation. :)

First of all, let me tell you that all of the modulars I have connected come with an empty 2" PVC conduit installed from the bottom of the load center stubbed out to the crawl space underneath. I assume that this was meant for the installation of the main feeders for the house, and that is what I use it for.

While many would install SER cable into that conduit, there are some who actually connect more conduit to that stub-down and run the 2" PVC to the outside disconnect. I am one such contractor that does this, and uses type THHN/THWN copper conductors in that conduit.

That being said, I would like to point out that most modulars are lacking an additional empty conduit for the installation of circuits required to be installed after the house has been set: i.e) Water pump, lift pump, HVAC circuits, crawl space lighting, etc. I would personally like to see at least a 1?" PVC conduit installed for this purpose if not larger.

While I have your attention, I will add a few more things concerning the main panel in those modulars:

1) IF the panel is rated for mounting with the mains at the bottom (most manufacturer's are, including Square D, and Cutler-Hammer, for example) then please mount them with the mains oriented that way. Too often we have to route those main cables through the panel enclosure and occupy the space reserved for the branch circuit conductors to reach the main breaker at the "top"

2) Please provide suitable ground-bars for the termination of equipment grounding conductors.

3) If you are installing a Cutler-Hammer (Bryant) panel, then please do NOT use the the remote neutral bar, unless you install an insulated jumper wire to the main neutral bar. That remote neutral bar is connected to the main neutral VIA the bonding jumper, and a grounding strap. IF it is utilized as a neutral, AND as a sub-panel as is the case most of the time, I am faced with having to re-configure it by removing the bonding jumper, the grounding strap, and installing a large insulated jumper wire to the main neutral assembly. I also have to procure additional lugs to accomplish this and feel that a simple procedural change by those who are in the factory could avoid such problems in getting the installation to be in compliance with the Code and passing the requisite inspections.

The preferred procedure in such cases would be to use the main neutral bar for all the neutral wires, and the remote bar for all your equipment grounding conductors. This way, all I need to do is remove the main bonding jumper, and replace the grounding screw on the grounding strap. This effectively separates all the grounds from the neutrals without having to do anything else. Again, I am specifically referring to Cutler-Hammer panels here, which most modulars that I have connected are equipped with.

4) In modulars that are built with an attic space (especially Cape Cod types), an additional empty conduit (1?" or larger) should be installed for future circuits.

Thanks again for listening to me vent on this issue. :D

[ November 28, 2005, 09:28 AM: Message edited by: kbsparky ]
 
Re: PVC into bottom of panel

While many would install SER cable into that conduit
they would ??
550.33 Feeder
(A) Feeder Conductors Feeder conductors shall consist of either a listed cord, factory installed in accordance with 550.10(B), or a permanently installed feeder consisting of four insulated, color-coded conductors that shall be identified by the factory or field marking of the conductors in compliance with 310.12. Equipment grounding conductors shall not be identified by stripping the insulation.
 
Re: PVC into bottom of panel

Concerning the use of the HUD certifications that has been brought up in this thread, let me offer the following observations:

1) Mobile homes that are built with steel frames and have axles and wheels attached. These are usually the type subject to HUD certifications and requirements. So-called Double-wides can be included in this classification. Some juruisdictions do not allow such homes to be permanently set.

2) Modular homes on the other hand, are built with conventional framing and are placed on steel-framed trailers for transport only and are then set in place on permanent foundations usually with a crane. The empty trailers are returned to the factory for reuse with another unit. These are not HUD certified, and as such usually are subjected to the building codes (including electrical codes) of the local jurisdiction where they are ultimately placed.
:D
 
Re: PVC into bottom of panel

quote: While many would install SER cable into that conduit

they would ??
The would and do! Because of the differences between mobile (subject to article 550) and Modular (not subject to said article), many of my competitors routinely use SER cable for their connection.

The meter box and main disconnect box can be mounted directly on the exterior of a modular, same as any other stick-built home, with the sub-feed cable run to the inside load center.

Such is not the case when dealing with the mobile homes, as the provisions of article 550 kick in. ;)
 
Re: PVC into bottom of panel

Better recheck 550!!! Manufactured (modular)Homes are included in Article 550
From NEC 550.2 Definitions:
Manufactured Home. A structure, transportable in one or more sections .... which is built on a chassis and designed to be used as a dwelling with or without a permanent foundation ....

I repeat my earlier assertion that Modular homes are not built on a chassis, but are built using conventional construction, require a permanent foundation, and therefore are not subject to the provisions of Article 550.

If you read further to the FPN, you will find that they reference the HUD standards, and I can assure that these modulars are NOT subjected to those, either.

While some mobile homes can be set with or without a permanent foundation (as the definition stipulates), modulars can not be set without one.
 
Re: PVC into bottom of panel

To clarify this a bit further, many in the industry stopped calling mobile homes trailers and then later started referring to them as manufactured homes. Seems there was a stigma attached to the terms Trailer and Mobile Home.

The Code kept up with this change of terms and cross referenced them both in their definitions in 550.2.
 
Re: PVC into bottom of panel

OK, Then your talking 545,Manufactured Buildings,they have quiet a few rules of their own also.
No argument here. But there are not that many rules per se, that set the modular homes apart from any other house.

A couple of things that stand out here is the use of what I call "non-box" devices (I hate those BTW), and those "Amp" connectors which are used to connect circuits across the marriage walls.
 
Status
Not open for further replies.
Top