My first mobile home

[mccayry]

This will be my first mobile home service that I have installed. It will be a 200A overhead service. I plan on running 4- wire 4/0 AL from the Panel on the pole in pvc conduit attatched to the underside of the trailer up into the trailers panel. Does the trailers panel need bonded or just the panel/Disco on the pole? Any help or advice would be much appreciated. Thanks

 

[Little Bill]

This will be my first mobile home service that I have installed. It will be a 200A overhead service. I plan on running 4- wire 4/0 AL from the Panel on the pole in pvc conduit attatched to the underside of the trailer up into the trailers panel. Does the trailers panel need bonded or just the panel/Disco on the pole? Any help or advice would be much appreciated. Thanks

You treat the mobile home's panel as a sub panel. Keep the EGC and neutral separate. You would need to bond the EGC to the panel tub, but not the neutral. At the service is where you bond the ground and neutral.

 

[jumper]

You treat the panel like a sub panel, bond the panel and separate the grounds and nuetrals- which should have been done at the factory. Make sure the frame is bonded.

 

[Dennis Alwon]

Think of it as the pole is the main service and you are wiring a separate structure. You need ground rods bonded to the equipment ground bar and the neutral bar separate.

 

[augie47]

Your feeder must comply with 550.33 (note "insulated" equipment ground).
The HUD inspection covers all the mobile home wiring including bonding, however, if it is a double-wide you need to make sure the bond between the sections is in place (normally on one end using a #8 bare)
Since you are in TN I will mention if the inspection is handled by a State inspector he will normally look for the State of TN Anchoring Decal and will
verify that there are smoke detectors in all bedrooms (on used homes these often have to be added) before allowing power. Local jurisdictions may vary.

 

[jumper]

I saw Gus's post and was looking at that section and just noticed 550.32(D). I have never wired a resi trailor, but this seems important also, because it seems that if you use the pole disco/panel the 4/0 feeder is too small.

(D) Additional Outside Electrical Equipment. Means for
connecting a mobile home accessory building or structure
or additional electrical equipment located outside a mobile
home by a fixed wiring method shall be provided in either
the mobile home service equipment or the local external
disconnecting means permitted in 550.32(A).

 

[mccayry]

The trailer is new single wide and does have smoke detectors. I did notice that the electrical nameplate on the trailer said 100A supply but the panel has a 200A Disco. I thought that was odd. What type of wire would you guys recommend between poco/meter and meter/trailer.

 

[augie47]

I saw Gus's post and was looking at that section and just noticed 550.32(D). I have never wired a resi trailor, but this seems important also, because it seems that if you use the pole disco/panel the 4/0 feeder is too small.

(D) Additional Outside Electrical Equipment. Means for
connecting a mobile home accessory building or structure
or additional electrical equipment located outside a mobile
home by a fixed wiring method shall be provided in either
the mobile home service equipment or the local external
disconnecting means permitted in 550.32(A).

(I changed your reference to 550.32(D)... I think that is correct)
I believe the wording of 550.33(B) allows you to use the 4/0 AL in this case.

 

[augie47]

The trailer is new single wide and does have smoke detectors. I did notice that the electrical nameplate on the trailer said 100A supply but the panel has a 200A Disco. I thought that was odd. What type of wire would you guys recommend between poco/meter and meter/trailer.

Most often used here is XHHW or USE/RHW

 

[Little Bill]

I saw Gus's post and was looking at that section and just noticed 550.32(D). I have never wired a resi trailor, but this seems important also, because it seems that if you use the pole disco/panel the 4/0 feeder is too small.

(D) Additional Outside Electrical Equipment. Means for
connecting a mobile home accessory building or structure
or additional electrical equipment located outside a mobile
home by a fixed wiring method shall be provided in either
the mobile home service equipment or the local external
disconnecting means permitted in 550.32(A).

The ones I have dealt with have a meter/panel combo at the pole and HVAC is connected there. So the feeder to the mobile home can be smaller.

 

[jumper]

(I changed your reference to 550.32(D)... I think that is correct)
I believe the wording of 550.33(B) allows you to use the 4/0 AL in this case.

If I use the pole/outside panel for the HVAC or other stuff, the feeder no longer carries the whole load. The section says "shall be permitted", but I do not see an exclusion to the requirement of the feeder to carry the whole load as 310.15(B)(7) states.

(B) Feeder Capacity. Mobile home and manufactured
home lot feeder circuit conductors shall have a capacity not
less than the loads supplied, shall be rated at not less than
100 amperes, and shall be permitted to be sized in accordance
with 310.15(B)(7).

 

[augie47]

Jumper, I think you are correct, but since the feeders are normally XHHW/RHW/THWN as opposed to NM/SE, we can still use 310.16 and 4/0 AL has an ampacity of 180 amps (75?.). next larger breaker is 200.

 

[jumper]

Jumper, I think you are correct, but since the feeders are normally XHHW/RHW/THWN as opposed to NM/SE, we can still use 310.16 and 4/0 AL has an ampacity of 180 amps (75?.). next larger breaker is 200.

Works for me. Thanks.

 

[Twoskinsoneman]

If I use the pole/outside panel for the HVAC or other stuff, the feeder no longer carries the whole load. The section says "shall be permitted", but I do not see an exclusion to the requirement of the feeder to carry the whole load as 310.15(B)(7) states.

(B) Feeder Capacity. Mobile home and manufactured
home lot feeder circuit conductors shall have a capacity not
less than the loads supplied, shall be rated at not less than
100 amperes, and shall be permitted to be sized in accordance
with 310.15(B)(7).

Yeah such a poorly written section. I saw that MH had a proposal to get it fixed for 2011. It was originally accepted then in the end the verbage was left alone... bummer