Dwelling unit - outbuildings

[tcduplex]

How do you calculate feeder/service load calculations for a dwelling unit outbuilding?

Outbuilding size - 40x60
Lighting - 6 fluorescents 2 amps each.
Outlets - 10
Furnace - 20 KW
Heat Pump - 33.4 min. circuit ampacity
Garage door opener - 2 @ 1/2 H.P. each
2 - 50A misc. outlets on same circuit

Is an outbuilding calculated using commercial load techniques or dwelling unit calculations?

How do you address the 50A outlets?

 

[buddhakii]

What do you mean by outbuilding. What will this be used for exactly. Maybe look at 220.14(J).

 

[Dennis Alwon]

This is a non dwelling unit then you must use the non dwelling calculations

 

[tcduplex]

Reply

Reply

The outbuilding is a storage building behind a dwelling unit.

 

[haskindm]

You don't address the 50-amp outlets, you address the load that will be connected to these outlets. What is the purpose of the outlets?

 

[ptonsparky]

The 50 amp recepts are for a welder.:grin:

 

[haskindm]

Then do an article 220 load calculation using the nameplate amperage for the welder(s), and determine the feeder ampacity that is needed. If this unit is to be fed from another building, you will also need to do a load calculation on that building to determine if the existing service is adequate. There are no shortcuts.