Electrical to storage shed.

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Shawndeer74

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Owensboro,KY USA
Hello all,
I've been planning to add a small 30amp panel to my storage shed for lights and a few convienience receptacles and can't find in the code book information pertaining to detached structures NOT on a permenant foundation. Our local electrical inspector said that because it's not a permenant foundation I would have to set a post and attach a weatherproof twistlock receptacle to plug the building into similar to an rv. I've only been a master electrician for a few years and feel like I should be able to find this but I'm not having any luck. Any help would be appreciated.
 
I agree with Dave. Most sheds around here just sit on the ground or a gravel bed and are still wired like a permanent structure. In the case of the OP he will need a GES at the separate structure.
 
Two suggestions:
1. Make sure there is not a local rule pertaining to this
2. Take a look at 225.39 in regard to sizing your disconnect.
 
augie47 said:
Two suggestions:
1. Make sure there is not a local rule pertaining to this
2. Take a look at 225.39 in regard to sizing your disconnect.
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This may be the case regarding the foundation. Are you referring to only being able to use 30 amp disconnect for 2 circuits if the calculated loads are less than 30 amps?
 
Shawndeer74 said:
This may be the case regarding the foundation. Are you referring to only being able to use 30 amp disconnect for 2 circuits if the calculated loads are less than 30 amps?
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Yes. The way I read it, if you are feeding more than two branch circuits, the disconnecting means must have a 60 amp rating.
 
augie47 said:
Yes. The way I read it, if you are feeding more than two branch circuits, the disconnecting means must have a 60 amp rating.
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But does that mean you must also run a 60 amp feeder conductor? IMO that isn't very clear at all.

What is (logically) wrong with 40 amp 120 volt feeder if supplying only 2 20 amp circuits? Design wise if starting from scratch it probably still makes more sense to go with a 20 amp MWBC though.

Used to see a lot of old farm buildings that only had two wire feed running to them (120 volts only) Most only had a 30 amp fused disconnect as the original service disconnect, but may have double pole disconnect and two branch circuits with 8 AWG service entrance conductors.
 
cowboyjwc said:
Then read article 210, because once you run power to it, there are several other requirements.
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more mandatory requirements for a dwelling accessory building then other then a dwelling accessory building, as in the dwelling accessory has some required outlets where other buildings may not.

Old farm buildings I mentioned before I don't consider to be dwelling accessory buildings. Should not be required to install at least one lighting outlet (often is at least one anyway) or at least one 15/20 amp 120 volt receptacle outlet (often is at least one of those as well). Sure there have been fires in such buildings over the years. I bet very few if any were directly related to sizing of supply conductors to the building though. More likely heat lamps and close proximity to combustible materials is a major cause of a lot of such fires. Still less fires then when kerosene lanterns were used for light, so I think we made some improvement there.
 
Thanks for all the info guys. The main reason I wanted power at my building is for an above ground pool pump so I've decided to save my money and just run a gfci receptacle for my pool pump. If I figured correctly my 20a 120v gfci located 130' from my house panel would require #8 wire to allow for voltage drop. If this is incorrect could someone please tell me.
 
Shawndeer74 said:
Thanks for all the info guys. The main reason I wanted power at my building is for an above ground pool pump so I've decided to save my money and just run a gfci receptacle for my pool pump. If I figured correctly my 20a 120v gfci located 130' from my house panel would require #8 wire to allow for voltage drop. If this is incorrect could someone please tell me.
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Size needed depends on load and maximum voltage drop you want to allow. What is HP of pump, presume it will be 120 volts based on other information given.
 
kwired said:
Size needed depends on load and maximum voltage drop you want to allow. What is HP of pump, presume it will be 120 volts based on other information given.
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The motors max amps is 9.6a. Being continuous duty x 125% is around 12 amps. If I allow 3% for voltage drop I think I can use 10 awg wire. That would be great.
 
Shawndeer74 said:
The motors max amps is 9.6a. Being continuous duty x 125% is around 12 amps. If I allow 3% for voltage drop I think I can use 10 awg wire. That would be great.
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That 125% for continuous duty is for determining minimum conductor ampacity and overcurrent device selection.

Voltage drop will be dependent on actual load, which may not even be 9.6 amps if motor isn't fully loaded to it's capacity, many would use 9.6 amps anyway though. Reality is if motor is never loaded to more then 7.9 amps, voltage drop will never be more then whatever 7.9 amps draw gives you.

Still looks like you need 10AWG though if you want no more then 3% VD. But if your actual load were 7.9 like I gave as an example, you are starting to get closer to being able to use 12 AWG and still be at 3% VD.
 
peter d said:
It never ceases to amaze me the things that inspectors dream up. :slaphead::roll:
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210.52(G) Basements, garages, and accessory Buildings. ....at least one receptacle outlet shall be installed..... 210.52(G)(2) Accessory Buildings. In each accessory building with electric power. I've got enough stuff to call without dreaming anything up.
 
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cowboyjwc said:
210.52(G) Basements, garages, and accessory Buildings. ....at least one receptacle outlet shall be installed..... 210.52(G)(2) Accessory Buildings. In each accessory building with electric power. I've got enough stuff to call without dreaming anything up.
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Do you require the absurdity that the OP described?
 
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