Was asked by general I work for to put sub panels in ten res units they are old studio units with very few receps no appliances other than fridge. They do not want multiple meters. They are all attached. They are all being fed from one panel which will be removed. Since there is no scope I am a bit lost on how to lay this out correctly. Of course they want it cheap as possible. any input would be appreciated
panels
- Thread starter normbac
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Buck Parrish
Senior Member
- Location
- NC & IN
You will have to install all new feeders.
All units will need disconnects. You can't have more then 6. So you will need to add a main disconnect and a gutter.
This will not be a " cheap " project
Some units may be sharing circuits.
230,72 c - multiple occupancy
230.23 -minimum size
All of NEC 230 will help you ,and 250
All units will need disconnects. You can't have more then 6. So you will need to add a main disconnect and a gutter.
This will not be a " cheap " project
Some units may be sharing circuits.
230,72 c - multiple occupancy
230.23 -minimum size
All of NEC 230 will help you ,and 250
texassparky
Member
- Location
- Dallas / Ft. Worth
How does that old saying go ?
You can find a Bad Job done Cheap, and Cheap Job done Bad, but if you want a Job done Right you have to pay the Right Price. :smile:
something like that ?
am I reading 230.23 correct I can use 40 amp panels if the load permits these are 400 sq. ft studios with one circuit in bath one in combo liv- bed & one in kit
also would the main cb be calculated by the amount of 40amp subs used or would there be a percentage allowed? TIA
also would the main cb be calculated by the amount of 40amp subs used or would there be a percentage allowed? TIA
Doug S.
Senior Member
- Location
- West Michigan
40a panels? I don't even want to know if it can be done.
think I worded that wrong 40 amp cb protecting # 8 feeder for a 60 amp rated sub in the studio, since there are only 3 branch circuits I didnt want to spend more than necessary, actually this building looks like it should be torn down but they want to rent them any way slumlords for sure.
Don't you need at least 4 circuits -- two kitchen small appliance circuits, a bathroom circuit, and a general lighting circuit? You'd use the normal demand load calculation to determine the rating of the feeder (3 VA per square foot for general circuits, 3000 VA for the two kitchen appliance circuits, 0 for the bathroom).
This will come out to something under a 20A feeder. You'll get hit by the other rule that says for more than 2 circuits you need at least a 30A feeder. So a 10-3 feeder would probably cover it.
How will these feeders be fed? That old central panel which is being removed -- is it being replaced with a new one? Are you running service conductors or a feeder to each unit? I think feeders will be cheaper than service conductors (no main breaker needed in the subs, no conduit requirements, no minimum size requirement, but you'll need that main distribution panel), and you could have issues with service conductors going too far into the building before hitting a main.
This will come out to something under a 20A feeder. You'll get hit by the other rule that says for more than 2 circuits you need at least a 30A feeder. So a 10-3 feeder would probably cover it.
How will these feeders be fed? That old central panel which is being removed -- is it being replaced with a new one? Are you running service conductors or a feeder to each unit? I think feeders will be cheaper than service conductors (no main breaker needed in the subs, no conduit requirements, no minimum size requirement, but you'll need that main distribution panel), and you could have issues with service conductors going too far into the building before hitting a main.
electrical in units is existing only want to put each unit with their own sub so tenants dont have to go in alley to reset breakers Main panel is junk and needs to be replaced anyway which is downstairs in the alley behind units just wasnt sure how to calculate loads in these units since they dont have many circuits no appliances, washer, no a/c etc wasnt sure about minimum sub panel requirements. figured I would run a feeder off a new main panel to each unit
- Location
- Massachusetts
I think you can forget about this job as it can not be done cheap.
Article 230 will have nothing to do with the new feeders or panels, that Article only covers the service which ends at the service disconnect. These are feeders and would be covered by 215.
215.2(A)(1) requires that the feeder be sized per Article 220.
So you must do a load calculation for each unit to determine the feeder and panel size. The fact that the units are currently wired below code does not let you install a new feeder and panel below code.
I would also strongly suggest you talk to the AHJ there may be local rules that force you to update the existing units wiring when you install this new feeder and panel.
Article 230 will have nothing to do with the new feeders or panels, that Article only covers the service which ends at the service disconnect. These are feeders and would be covered by 215.
215.2(A)(1) requires that the feeder be sized per Article 220.
So you must do a load calculation for each unit to determine the feeder and panel size. The fact that the units are currently wired below code does not let you install a new feeder and panel below code.
I would also strongly suggest you talk to the AHJ there may be local rules that force you to update the existing units wiring when you install this new feeder and panel.
Confused In part 3 the load of the washer and dryer are seperate from the units (one wash room used by all tanants) must I still add these loads per Part 3 ? also no electric heat and no appliances
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