mobile home grounding

[hobbes1070]

Hello everyone
I am in need of a little help, I need to know the service grounding req's of a mobile home. If any one out there has done 1 before and could help I would greatly appreciate it
Thanks work safe and remember 110-12

 

[gserve]

Re: mobile home grounding

The service is grounded by 2 ground rods 6' apart at the service pole or pedestal.The home is fed with a 4 wire feeder and ground and neutral are isolated in the mobile home panelboard.There ia a bond wire run from the ground bar to the mobile home frame to bond it.It is usully a #8 solid(100A)If this is a doublewide there will be a bonding jumper from frame to frame that needs to be attached when the home is set up.

 

[pierre]

Re: mobile home grounding

It is important to remember to keep the 'grounded conductor' and the 'equipment grounding conductor' separated in the mobile home or structure at all locations. The grounded conductor is to be isolated from the frame of the structure.

Pierre

 

[LocoKen]

Re: mobile home grounding

To add more to this post, I am new to this forum and am new to the electrical field. My boss sent two of us out to a mobile home service job the other day. I noticed that in the mobile home panel/meter outside that the nuetral bus on the meter side was bonded to the ground/nuetral bus on the disconnect side. Do the grounds and nuetrals need to be seperated here? I know we seperated the grounds and nuetrals in the panel inside the mobile but not outside. Why is this? I haven't had the opportunity to ask the journeyman I was working with as of yet.

[ August 22, 2005, 02:09 PM: Message edited by: LocoKen ]

 

[tom baker]

Re: mobile home grounding

The grounded neutral conductor is a current carrying conductor. If a neutral to case bond is made on the load side of the service, neutral current will be on all conductive metal objects that are bonded to the mobile home disconnect.
A fire, shock or death could result.

 

[LarryFine]

Re: mobile home grounding

To add, Ken, the entire service disconnect enclosure at the pedestal is considered the line side, so it is appropriate that the neutral and equipment ground are one and the same.

Any time there is a disconnect ahead of, and separately enclosed from, the electrical panel, the panel is considered a sub-panel, which is why it's wired as such.

In other words, at the main disconnect, there should be an incoming neutral and both a neutral and equipment ground going out. It seems redundant, but it is not.

 

[LocoKen]

Re: mobile home grounding

So, if I'm hearing you all correctly, this is what the MH Service Panel should look like:

[ August 24, 2005, 12:14 AM: Message edited by: LocoKen ]

 

[hurk27]

Re: mobile home grounding

It is allowed to use a 3-conductor feeder between the main service and a disconnect for a manufactured home (MH)
If the manufactured house is directly fed from the service equipment to the panel inside the home it will be required to run a 4-wire with an insulated grounding conductor. But if a disconnect is installed in between the service equipment and the panel inside of the home then a 3-wire feeder can be installed up to the disconnect but a 4-wire will still be needed to run to the panel. And the main bonding jumper will be installed at this disconnect, as well as a grounding electrode system.

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.

Exception: Where a feeder is installed between service equipment and a disconnecting means as covered in 550.32(A), it shall be permitted to omit the equipment grounding conductor where the grounded circuit conductor is grounded at the disconnecting means as required in 250.32(B).

First part is for a direct feed from the main service and the second part is where a disconnect is used between the service and the home.