J Allan
Member
- Location
- McHenry, Md
Per 550.33 (A) (1) Why are Feeder Grounding Conductor (EGC) for Mobil Homes required to be insulated.
Mobil Home Feeder
- Thread starter J Allan
- Start date
- Status
- Location
- Tennessee NEC:2017
- Occupation
- Semi-Retired Electrician
My best guess is most mobile home feeder conductors are aluminum and ran underground. Aluminum doesn't do well underground when not insulated.
J Allan
Member
- Location
- McHenry, Md
Thanks for your input, that could be the answer as it is an old requirement. So it would not have to be insulated if it was not exposed to soil conditions, ie installed in a conduit. I run across some Mobil Homes that are on foundations. If you have a foundation then the Meter can be installed on the Mobil homes, as it is now a Manufactured Home. So if that is the case you will not need an insulated ground in both of these cases, would that be correct. I have asked many Electrician's this and no one has an answer.
- Location
- Tennessee NEC:2017
- Occupation
- Semi-Retired Electrician
What I said was just my opinion, nothing more. I don't give it much thought really, because all the mobile home feeder I buy has the insulated ground. Unless you're just curious, I would just get the MH feeder and not have to worry about it. It's just USE-2 or RHW-2 conductors. The 200A is 4/0-4/0-2/0-4 Al., each conductor is color coded as required.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
It may be part of why MH appliance circuits have "always" been 4-wire: because of the metal chassis.
J Allan
Member
- Location
- McHenry, Md
As an Inspector I come across many ways that Contractors perform there job. I like to know why a Code says what it says so I can make a determination if the intent of the Code is made. I always thought it was because of the metal Chassis, but at the end of the day, the chassis is Bonded to the Panel Ground. Thank you both for your input, but I still do not know the answer.
Fred B
Senior Member
- Location
- Upstate, NY
- Occupation
- Electrician
Maybe if someone is aware of when that was added to the code then maybe a review of the code panel justification can be made for definitive rationale.
- Location
- Tennessee NEC:2017
- Occupation
- Semi-Retired Electrician
Where would you ever find a reason to run a bare EGC in a MH feeder? What type conductor would you even use for that?
J Allan
Member
- Location
- McHenry, Md
Some jobs the Contractor or Homeowners install SER cable, after awhile you see a little bit of everything, especially with Homeowners. The one the other day the Pedestal for the Meter and disconnect was only 12" from the Mobil Home, and the Contractor installed SER Cable in a 3" Conduit above grade to the inside Panel, so would that be allowed, as the ground is not insulated, but it goes to a Mobil Home. What are your thoughts ? Also as I mentioned previously, when a Mobil Home is on a foundation and SER Cable is used to the Panel is that allowed. As I do not know why a insulated ground is required, I am not making an educated decision. I understand why an insulated ground is required for a Feeder for a Pool House, but not a Mobil Home. I agree with Fred B I would probably have to go to the original Code Committee hearing notes.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
No ser whether installed in a conduit or not does not have an insulated equipment grounding conductor. There is a difference between covered and insulated. Ser has a covered ground but not an insulated ground.
J Allan
Member
- Location
- McHenry, Md
I know that, we are getting off base. I feel like I am on a job site. My question is the first Post.
- Location
- Tennessee NEC:2017
- Occupation
- Semi-Retired Electrician
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Wow, you asked question about SER- which is, as you say, off topic, you get a response and then you get upset. Remember many members here are also guys from the job site...lol
J Allan
Member
- Location
- McHenry, Md
| (Southwire Cable Tech Support) Sep 27, 2021, 2:58 PM EDT Allan, In my experience, mobile home services are comprised of utility service conductors connected to a power pole (main power disconnect) and then through a feeder from the pole to the mobile home. This feeder requires an EGC and is normally installed underground. Bare conductors are not allowed in underground installations, even for the EGC. If the feeder is installed above ground, there may be concern for a higher probability of mechanical damage to the feeder going into a mobile home (versus other kinds of buildings). FYI, here is the response from Southwire. It makes sense to me, and is in line with what was said by you guys. I would like to thank you all for your input, I read your reports all the time and it helps me. |
- Status