200A Panel with less than 4/0 aluminum

Status
Not open for further replies.
retirede said:
I think the bottom line is that a mobile home can be relocated rather easily, hence the requirement to be able to deenergize away from the structure.

A modular home, once installed on site is more permanent.
Click to expand...
A modular home is completely permanent.
And it doesn't have any Wheels attached to the structure
 
Doc13067 said:
Thanks for all the info guys. Very informative. I wonder if the lesser standards have to with the possibility that the systems in the home may not be permanently connected to the earth.
Click to expand...
I don't think whether it's permanently connected to Earth or not has anything to do with it. It just doesn't really make any difference IMO whether it's permanently connected to Earth or not.

Like a lot of things someone came up with this idea at some point and other people voted for it. There may be no technical reason to do it. It might just be a practical thing because trailers are occasionally moved and it's convenient to have the electrical meter not move. That would be my guess as to what the thinking is.
 
Doc13067 said:
Thanks for all the info guys. Very informative. I wonder if the lesser standards have to with the possibility that the systems in the home may not be permanently connected to the earth.
Click to expand...
It still connected to earth. What is different is the location of service equipment which is where that connection will be. The EGC's are still at same potential as the grounded conductor back at the service like they are in all feeder situations.
 
Doc13067 said:
Thanks for all the info guys. Very informative. I wonder if the lesser standards have to with the possibility that the systems in the home may not be permanently connected to the earth.
Click to expand...
The lesser standard is a result of conflicting codes, HUD and NEC. NEC is a voluntary code that is applied only when adopted in by states, HUD is a federal regulatory agency and can supersede the NEC recommendations and any local or state regulations. The regulations within HUD related to mfg housing was a result of a totally unregulated building method and the need for some safety standardization of a sometimes very hazardous structure that resulted in deaths. Industry was unwilling to self regulate in preference to profit, thus regulation. Control remained with HUD and with it the older electrical standards and with selective upgrades to the HUD electrical standards, as opposed to what we generally deal with as field electricians.
 
Fred B said:
The lesser standard is a result of conflicting codes, HUD and NEC. NEC is a voluntary code that is applied only when adopted in by states, HUD is a federal regulatory agency and can supersede the NEC recommendations and any local or state regulations. The regulations within HUD related to mfg housing was a result of a totally unregulated building method and the need for some safety standardization of a sometimes very hazardous structure that resulted in deaths. Industry was unwilling to self regulate in preference to profit, thus regulation. Control remained with HUD and with it the older electrical standards and with selective upgrades to the HUD electrical standards, as opposed to what we generally deal with as field electricians.
Click to expand...
Yet newer mobile homes pretty much still are completely burned out whenever there is a fire in them. a little drywall/gypsum board of some kind does wonders for slowing spread.
 
kwired said:
Yet newer mobile homes pretty much still are completely burned out whenever there is a fire in them. a little drywall/gypsum board of some kind does wonders for slowing spread.
Click to expand...
Not saying they are adequate, just the rationale. AFA fire reduction the new are better than the old but no where near a stick build. Old one would burn like a stack of dry paper and be gone before a fire department less than a half mile away could reach it with the first drop of water.
 
Fred B said:
Not saying they are adequate, just the rationale. AFA fire reduction the new are better than the old but no where near a stick build. Old one would burn like a stack of dry paper and be gone before a fire department less than a half mile away could reach it with the first drop of water.
Click to expand...
FWIW I can tell you from experience stack of paper doesn't burn very fast. too dense and only burns at the surfaces. Spread it out somehow to get more surfaces and it will burn fast though. ;)
 
Interesting history about the HUD rules and need for regulation... When it comes to running conduit under these manufactured homes, do you guys have a preferred method? I was thinking of finding a way to strap EMT to the under side of the I beams.
 
FYI I hate to be the guy always asking questions. So I made a rule that for every post I make I look through other posts to try and answer questions that some others may have. But every damn time i can’t answer it better than the already existing answers haha. So I am trying to contribute as much as I benefit there’s just a lot of wisdom to contend with here.
 
Doc13067 said:
Interesting history about the HUD rules and need for regulation... When it comes to running conduit under these manufactured homes, do you guys have a preferred method? I was thinking of finding a way to strap EMT to the under side of the I beams.
Click to expand...
I am assuming your getting the conduit idea from 550.15 (h) ?. I never use conduit under manufactured houses that have a permeant foundation. I can see this for a mobile home, though if it has a skirting I would still not.
 
Doc13067 said:
Interesting history about the HUD rules and need for regulation... When it comes to running conduit under these manufactured homes, do you guys have a preferred method? I was thinking of finding a way to strap EMT to the under side of the I beams.
Click to expand...
Beam clamp and saddle type straps. Or in some cases if running near the "outer" portion of the underside there may be thinner wall steel there and self drilling screws may work out there.

Most time I am running either the feeder circuit in this manner or the AC or other accessory that will very likely get disconnected if the home is ever moved again.
 
kwired said:
Beam clamp and saddle type straps. Or in some cases if running near the "outer" portion of the underside there may be thinner wall steel there and self drilling screws may work out there.

Most time I am running either the feeder circuit in this manner or the AC or other accessory that will very likely get disconnected if the home is ever moved again.
Click to expand...
That’s exactly what I’m thinking of doing and that is what I’m running.
 
For these mini splits, does anyone know where they get the neutral? The outside unit that I’m providing electric for is 240 not 120/240. It shows 2 hots and a ground getting connected. Yet the control wires that go inside have what I believe is a neutral. Is that going back down the ground ultimately? If so I that’s no good for a manufactured home with a sub panel because the ground is isolated in the panel. My concern is I don’t want to send neutral current from the inside unit down the ground from my disco.
 
Doc13067 said:
For these mini splits, does anyone know where they get the neutral? The outside unit that I’m providing electric for is 240 not 120/240. It shows 2 hots and a ground getting connected. Yet the control wires that go inside have what I believe is a neutral. Is that going back down the ground ultimately? If so I that’s no good for a manufactured home with a sub panel because the ground is isolated in the panel. My concern is I don’t want to send neutral current from the inside unit down the ground from my disco.
Click to expand...
These units are built on international design standards. That N is only a neutral in countries that have 240 volt two wire nominal supply and one conductor is a grounded conductor. In North American voltage systems that N is usually going to be connected to an ungrounded conductor.
 
AC\DC said:
I am assuming your getting the conduit idea from 550.15 (h) ?. I never use conduit under manufactured houses that have a permeant foundation. I can see this for a mobile home, though if it has a skirting I would still not.
Click to expand...
Manufactured homes we attached the disconnect on the outside and LB into the crawler or basement with SER. Mobile homes we trench over from the pedestal to just under the skirting and run Sched 80 along the ground and up into the panel, usually with a 100A worth of URD. Most the manufactured and mobiles we work with have 200A panels in them already and sometimes the mobile park only has a 100 breaker in the ped so what our AHJ lets us do is label the panel inside that says "Fed with 100A".
 
kwired said:
These units are built on international design standards. That N is only a neutral in countries that have 240 volt two wire nominal supply and one conductor is a grounded conductor. In North American voltage systems that N is usually going to be connected to an ungrounded conductor.
Click to expand...
What I’m referring to is the fact that the controls on the inside are not 240 volts. So I understand it steps down somewhere so where does the non 240 current go on it’s way back to the pole. Do I need to be running an insulated neutral to the disconnect or is it really just 2 hots and a ground that only carries current in the event of a fault?
 
Doc13067 said:
For these mini splits, does anyone know where they get the neutral? The outside unit that I’m providing electric for is 240 not 120/240. It shows 2 hots and a ground getting connected. Yet the control wires that go inside have what I believe is a neutral. Is that going back down the ground ultimately? If so I that’s no good for a manufactured home with a sub panel because the ground is isolated in the panel. My concern is I don’t want to send neutral current from the inside unit down the ground from my disco.
Click to expand...
The control wires that go inside are slaves to the outdoor unit. If they do use a neutral it will come from its own control transformer. Often times they are DC. It would create more of a hazard if you tried to modify the factory wiring by hooking up a neutral somewhere it wasn't needed.
 
Status
Not open for further replies.
Top