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| Subject - Subpanel Location | |
| Bruhlad |
Is there any requirement in the NEC for locating a subpanel? I need to wire a new addition (a kitchen)which is located a min. 30' from the main service panel (max. 60' from the farthest corner). I need to install a subpanel to handle 8 new circuits (the original kitchen had only one 20A circuit)and would like to place the panel as close to the kitchen as possible. Based on my load calcs and NEC 220.16(A), a 30-amp, 240 volt subpanel is sufficient. |
| zapped208 | No reason for a sub panel, take your home runs back to the main service. |
| Bruhlad | There aren't enough slots available in the existing service panel for the new circuits, even with tandem breakers. The panel was just upgraded 5 years ago, but before the new kitchen was planned. |
| lctrc789 | I would ask what size service you have in this home and how many circuits are used already. If you cannot add a new service with appropiate space available then yes you could add a sub panel. But why couldn't you add all the new circuits to the main panel? So how many circuits are you adding for new addition? 30 amp two pole feeder fo 8 20 amp circuits may be enough but really need to know what you are adding and so forth. |
| Bruhlad | I am primarily interested in any code regarding the location of a subpanel. (Local inspectors use only NEC 2002 - no other codes apply.) The details: Main service is 100 amps. Only 4 slots remain open. I need one for a new circuit to supply a 3/4 hp sump pump. The kitchen plan calls for 8 circuits: 2 15A circuits for lighting and receptacle loads, 1 15A circuit for the fridge (780W), 1 20A cuircuit for microwave (1000W), 1 20A for disposal (3/4hp/972W), 1 20A for dishwasher (1080W), and 2 20A small appliance circuits. |
| Bruhlad | For anyone else in Cincinnati, Ohio, whose been on the edge of their seat with this cliffhanger, here's the answer (from the Inspector himself): Subpanels may be located anywhere as long as the following restrictions are met: 1) panel is not located in a bathroom, bedroom or closet, 2)a clearance of 36" is maintained around the panel, and 3) max. height of breakers is 6'-7". For subpanels servicing more than two branch circuits, "the service disconnecting means shall have a rating of not less than 60 amperes." NEC 230.79 (D) Disclaimer: if you are not in Cincinnati, check with your local authority having jurisdiction. |
| lctrc789 | Well I guess the local code there have told you what you need to know, You must feed the sub panel with 60 amps minimum and then anywhere but a bath, bedroom or closet and you meet their requirments on height and clearance. A few years ago with my small residential company I ran into a similair situation, The customer had a 100 amp panel existing, with 18 circuits and it was loaded I tried to talk them in to changing to 200 amp panel but the way the panel was installed with a disconnect and almost 75 feet away from the loacation they could not afford that. I was worried that if I added a sub panel I would take the 100 amp panel past the expextations,(i.e.) to many circuits. I did get an inspector out there he did ok me to insall a 100 amp panel with a 60 amp main for the new circuits for their two new rooms and bath room. I had added 1 GFI circuit 20 amp for bath, one 230 v air conditioner circuit, two bedroom circuits, and one 15 amp circuit for 2 outside gfi s and and one circuit for lighting and recpt for a mini barn. The main panel was hard to locate because they added bath and bedrooms I had to have contractor to extend a hall wall for the panel. I wish you well with this poroject. |
| Mike Delaney | If I hadn't of read the post about 230.79(d), I still would be installing 50amp subpanels for basements and such...that SUCKS. We always would run 6/3(50amps) romex to a subpanel...never once did an inspector say anything...I think its funny that Bruhlad ask his question...and everyone else gave 'em every answer but the one he asked! |
| Pierre Belarge | Article 230 refers to service panels. Your panel is not a service panel. Refer to 215.2(A)(2) for the minimum size requirements, as 60 amps is not the minimum requirement for 'subpanels'. See 408.16 for overcurrent protection of the panel supply. Bruhlad You mentioned your calculation came to 30 amps , would you mind showing the math. Also panels can be installed in closets... as long as it is not a clothes closet or has no ignitable material. How about an "electrical closet"   .Pierre Pierre |
| Mike Delaney | Yeah that sounds better..I spoke to soon. 230.79 refers to service disconnects, not sub feed. If I was wiring that kitchen addition, I would run 50A instead of 30A, it wouldn't be to hard to trip that breaker with the microwave going, along with a couple other appliances. |
| Bruhlad | My mistake on the NEC 230.79 (D) reference. The local inspector here was actually referencing 225.39(D), which deals with feeders for OUTSIDE branch circuits and feeders. I think that would have applied as I originally planned the circuits, since I was going to run a 20A circuit from the subpanel to an outside recptacle. To reduce the feeder load, though, I am planning now to run that circuit directly from the main service panel and so 225.39(D) no longer applies and 215.2(A)2 does. Below are the loads I calculated for sizing the subpanel. SUBPANEL LOAD FOR 200 SF KITCHEN (BASED ON NEC 220) APPLIANCE/FIXTURE..........................WATTS..SUBTOTAL LIGHTING (MAX RATING........................1550 SMALL APPLIANCE CIRCUITS: 2 X 1500 = 3000.............. NEC 220.16 (A ) SUBTOTAL:........................................4550 FIRST 3000 @ 100%:...........................3000.............. NEC T220.11 BALANCE @ 35%:..............1550 X 0.35 = 543.............. NEC T220.11 SUBTOTAL:.....................................................3543 FASTENED IN PLACE APPLIANCE LOADS:....................... NEC 220.17 RANGE HOOD........................................540 FRIDGE...............................................780 GARBAGE DISPOSER...............................972 MICROWAVE.......................................1000 DISHWASHER (LARGEST MOTOR)............1080 SUBTOTAL:........................................4372 SUBTOTAL X 75% DEMAND LOAD:........................3279 NEC 220.17 LARGEST MOTOR X 25%:.....................................270 NEC 220.14 TOTAL LOAD:...................................................7092 SERVICE AMPS REQUIRED = WATTS/240V = 7092/240 = 30 FEEDER AMPACITY REQUIRED (MIN.) = 30 AMPS NEC 215.2(A)(2) |
| lctrc789 | Pierre , for the most part in residential if you install a panel in a closet you are in deep do do lol Residential is a total differnt aspect of the code and so many inspectors out there have a hard time in residential with the codes. The local codes enforced by some are almost scary and some don't care what the NEC states, I have one county that never allows a water ground under any circumstances and this causes problems with us because we always do a ground test and in many cases we have to do three ground rods. |
| Pierre Belarge | Pat It sounds typical just like other places, including the inspectors that work for my company  I find it hard to believe that they do not permit water grounds - is that because of the problem with pitting pipes? Knowing the code always helps when dealing with inspectors in our business  Pierre |
| JimmyDee | quote: The water system is bonded to the grounding system, isn't it? Jim |
| kbsparky | >>... in many cases we have to do three ground rods...<< What section of the NEC requires three ground rods? The most I've ever seen required was 2 ... |