Mobile Home Service

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Little Bill

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Tennessee NEC:2017
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Semi-Retired Electrician
Do you think 550.32(C) would allow a mobile home with a 100A service to have two 50A receptacles used to feed the inside panel. The 100A service is a 100A MB panel. Each receptacle is protected by a 50A breaker in the service panel. There are two cords, each with a 50A plug/cord cap, the other end is hardwired into the inside panel. The inside panel is a split bus panel. It has two 50A main breakers and each cord lands on a 50A breaker. Each main breaker protects one bus section.

This is an existing installation that I had to replace the service due to the ice storm we had.
I didn't take the time to check out all the requirements at the time. I just wanted to get the peoples power back on because of the freezing temperatures. The HO sent me a picture of the "rejection" sticker left by the inspector. I haven't talked to him yet, but I'm sure the cords, plugs, and receptacles are what he rejected it on.

550.32(C)
(C) Rating. Mobile home service equipment shall be rated
at not less than 100 amperes at 120/240 volts, and provisions
shall be made for connecting a mobile home feeder
assembly by a permanent wiring method. Power outlets
used as mobile home service equipment shall also be permitted to contain receptacles rated up to 50 amperes
with appropriate overcurrent protection
. Fifty-ampere receptacles
shall conform to the configuration shown in
Figure 550.10(C).
 

augie47

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Tennessee
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State Electrical Inspector (Retired)
Under today's Code it would be a violation of 550.10(A).
I can't imagine it ever being an allowable arrangement (it wasn't in '99, the oldest book at have available right now).
IMO, if you could show the arrangement was ever a "factory assembly" you might have some "wiggle room", otherwise put the wheels back on and drive it off on inspection day :D
 

Little Bill

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Location
Tennessee NEC:2017
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Semi-Retired Electrician
Under today's Code it would be a violation of 550.10(A).
I can't imagine it ever being an allowable arrangement (it wasn't in '99, the oldest book at have available right now).
IMO, if you could show the arrangement was ever a "factory assembly" you might have some "wiggle room", otherwise put the wheels back on and drive it off on inspection day :D

Gus, what do you think 550.32(C) means and what is it applying to. The words outlet and receptacle have an "s" at the end making them plural.

I was told it came from the factory that way. Also it was thought to have been designed for a construction trailer.
 

augie47

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Tennessee
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State Electrical Inspector (Retired)
Gus, what do you think 550.32(C) means and what is it applying to. The words outlet and receptacle have an "s" at the end making them plural.

I was told it came from the factory that way. Also it was thought to have been designed for a construction trailer.

I think (C) simply allows you to have additional outlets at the power source.
Multiple cords/disconnecting means to the mobile home seems to violate 550.10 & 550.32(C).
550.4 seems to mandate the same rules for construction trailer supply power.
Guess we just have top see what your inspector has to allow.
 

Smart $

Esteemed Member
Location
Ohio
I think (C) simply allows you to have additional outlets at the power source.
Multiple cords/disconnecting means to the mobile home seems to violate 550.10 & 550.32(C).
550.4 seems to mandate the same rules for construction trailer supply power.
Guess we just have top see what your inspector has to allow.
Hmm... sounds like the mobile home has a split bus panel... which means it's not parallel fed. Make any difference?
 

Dennis Alwon

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Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
What about this

550.10 Power Supply.
(A) Feeder. The power supply to the mobile home shall be
a feeder assembly consisting of not more than one listed
50-ampere mobile home power-supply cord or a permanently
installed feeder.
Exception No. 1: A mobile home that is factory equipped
with gas or oil-fired central heating equipment and cooking
appliances shall be permitted to be provided with a listed
mobile home power-supply cord rated 40 amperes.
Exception No. 2: A feeder assembly shall not be required
for manufactured homes constructed in accordance with
550.32(B).
 

Little Bill

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Staff member
Location
Tennessee NEC:2017
Occupation
Semi-Retired Electrician
I think (C) simply allows you to have additional outlets at the power source.
Multiple cords/disconnecting means to the mobile home seems to violate 550.10 & 550.32(C).
550.4 seems to mandate the same rules for construction trailer supply power.
Guess we just have top see what your inspector has to allow.


Well I didn't get an answer to how 550.32(C) applies from the inspector. But he did contact his boss and they came up with an "Andy Griffith" type solution. Sometimes you have to weigh the law against the concerns of people.;)

So together they decided that since this was existing and the damage to the service was from the ice storm, they would just "let it slide"!:thumbsup:
A lot of the folks that received this unexpected damage weren't financially ready for the associated cost to repair their electrical service. Then to add to the cost by requiring the feeder to be changed would put them in a terrible spot.

Also, since the cords had been there for a while and seemed to be in good shape and protected by OCPDs that were properly sized, no safety issue was expected.

BUT, if in the future, the power has to be cut and permit pulled, the feeder would have to be changed to a permanent method for it to pass inspection.
 

Little Bill

Moderator
Staff member
Location
Tennessee NEC:2017
Occupation
Semi-Retired Electrician
Well I didn't get an answer to how 550.32(C) applies from the inspector. But he did contact his boss and they came up with an "Andy Griffith" type solution. Sometimes you have to weigh the law against the concerns of people.;)

So together they decided that since this was existing and the damage to the service was from the ice storm, they would just "let it slide"!:thumbsup:
A lot of the folks that received this unexpected damage weren't financially ready for the associated cost to repair their electrical service. Then to add to the cost by requiring the feeder to be changed would put them in a terrible spot.

Also, since the cords had been there for a while and seemed to be in good shape and protected by OCPDs that were properly sized, no safety issue was expected.

BUT, if in the future, the power has to be cut and permit pulled, the feeder would have to be changed to a permanent method for it to pass inspection.

Bump!
 
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