OT-residential wiring question

for some reason the previous owner of my house ran a dedicated line for an outdoor receptacle. it's a 30' run from the main panel using a 12/2 w/gr romex in a conduit. it's on a dedicated 20 amp breaker. I just built a sun room where the outlet was. I moved the outlet to the outside of the new room. my question is: is this circuit enough to wire the room. there would be 3 ceiling fans with lights, 2 can lights, & 5 outlets. more than likely there would never be more than 2 outlets used at the same time.
 
My rule of thumb is a minimum of 2 15A circuits per room. You have to consider what loads might be applied to those convenience outlets. Is a stereo or TV set or possibly a small refrigerator going to appear in the near future? To me it's better to error on the side of safety.You may also want to check if any local building codes apply. If a fire should start because of an overload,your insurance might not cover damages if you skate codes or permits. It's your call how you go about it though. Just a thought! HTH
 
I would not depend on it but then I tend to wire heavy and use more then what is called for when I wire things. An example of it is this. If it is called for to have 12 gauge wire I use 10 gauge. And if it is called for a 20 amp breaker I use a 15 so that way the wire is over what is needed and the breaker is less so more protection
 
I usually go for overkill myself. it's just that getting another line over to this room is a p.i.t.a. I did just take a good look at a 100 amp sub-panel in my laundry room. it's fed with a 10-2 w/gr. it has a 15 amp side by side breaker, a 15 amp/20 amp piggy back breaker. & a 40 amp breaker feeding a 140 line for an electric range in the kitchen. since I'm not using the 40 amp ( gas range ) maybe I could pull that 40 amp breaker & use that space for the room. it's only 6 ft away & I could run thru the cantilever.
the next wiring project will be getting power to my shop. that's going to require a main panel upgrade, a sub panel & some service entrance cable.
 
I'm no electrician but I do know you will be putting more on one 20 amp circuit than I'd want to put on it.
 
One rule of thumb is to assign a maximum draw of 1.5 amps to each receptacle, which allows for 10 receptacles on a 20-amp circuit. You must use 12-gauge wire to connect 20-amp circuits; when you're installing receptacles in the bathroom, kitchen, laundry room or outdoors, they must be ground fault interrupting receptacles.

If I was reading your statement right you have 10-gauge feeding a 100 amp sub-panel? That 100 amp sub-panel should be fed with at least 2-gauge
 
Agreed. 10 ga. is not adequate to feed a 100 amp panel.
6 ga. minimum and the 20 amp circuit is adequate for you sunroom needs. Feed from the dedicated outlet w/ 14 ga. wire for your lites and outlets.
 
If you are doing nothing but adding a few lights and fans,It would"technically" be OK,however,if you want to use the external receptacle for powertools,etc.not so much. The lights and fans would use no more than 5-7 amps,but voltage drop can occur whenever connections are made through switches,receptacles where the wires are"backwired" by sticking the wires into the back of the unit. If the use would be expanded beyond what you described,It would be better to run bigger wires to a sub panel with 4-6 breakers and use 15 amp breakers. You say that the wire is in a conduit. I'll assume it's a 3/4",as I've tried to push a Romex through 1/2" and it won't go. You can use the Romex to pull 2 6g wires,and 1 12g or 10g for a ground,using a 30 amp breaker to feed it. This is dependent on your local regs.
 
(quoted from post at 10:51:15 10/12/14) for some reason the previous owner of my house ran a dedicated line for an outdoor receptacle. it's a 30' run from the main panel using a 12/2 w/gr romex in a conduit. it's on a dedicated 20 amp breaker. I just built a sun room where the outlet was. I moved the outlet to the outside of the new room. my question is: is this circuit enough to wire the room. there would be 3 ceiling fans with lights, 2 can lights, & 5 outlets. more than likely there would never be more than 2 outlets used at the same time.

The NEC does not limit the number of lights/receptacles you can have on a residential branch circuit. You just need to size the circuit to match the maximum anticipated load.

A ceiling fan motor is roughly equivalent to a 75W light bulb and the 20A branch circuit is adequate for the load you describe.

If you intend to use the space as a kitchen, breakfast, or dining area it must have a minimum of two 20A branch circuits sized for small appliances ( e.g. toaster) and the circuits can also be shared with the lighting.

TOH
 
I would just remember what you have for wiring, install low current LED lights, and if you ever put something out there that draws alot of current, add another circuit..
 
You should be fine, the circuit is "fused" for 20 amp which matches the 12 GA wiring. It has been brought up that a kitchen needs 2 20 amp dedicated circuits.

Your local building codes and inspector over rule anything we say.
 
(quoted from post at 19:57:23 10/13/14) Here a kitchen must have at least 2 20 amp circuits. Lighting can not be on them.

My first thought was the prohibition against lighting loads on the small appliance circuits must be a local code but a double check says otherwise. It is prohibited by the NEC. Obviously the local inspector and his code book have the final say on all of this ;-)

TOH
 
(quoted from post at 07:51:15 10/12/14) for some reason the previous owner of my house ran a dedicated line for an outdoor receptacle. it's a 30' run from the main panel using a 12/2 w/gr romex in a conduit. it's on a dedicated 20 amp breaker. I just built a sun room where the outlet was. I moved the outlet to the outside of the new room. my question is: is this circuit enough to wire the room. there would be 3 ceiling fans with lights, 2 can lights, & 5 outlets. more than likely there would never be more than 2 outlets used at the same time.

Code rules all of course...
but sure, with that light load.
But, if you are going to leave that 20amp breaker in the panel to feed it, all wiring after the panel must be 12 minimum.
(You might not be the last owner of your house...)
outside outlet means a GFI in the circuit is common sense mandatory. I hate getting sizzled.
best advice was already given. know your house.
I live in an old house, that had the panels upgraded to breakers before I bought it.
I've physically traced and looked at every wire in my years here.
I know which circuits I can plug heaters, air conditioners, even vacuum cleaners into and which ones I shouldn't even though all are rated enough on paper.
 
Rule of thumb, receptacles and ceiling lights should be on separate breakers.
You need to continue to run 12 guage wire on that 20amp breaker.
Just cause its a 20 amp breaker and 12 guage wire doesn't mean that you can run a 20 amp draw continuously. Old timer told me to stick to a 75% rule and you'll never go wrong.

Also you need to look at the possibility of having all of your lights on and having something plugged into all of your outlets at the same time. Yes you say you wont but it could happen. Dont know where you are geographically but my sun room turns cold when there is no sun and the 1500 watt oild radiator comes out that draws 15 amps alone.

All this aside you got bigger fish to fry. Your 100 amp sub panel with all those breakers and fed by only a 10/2 wire which is rated for 30 amps needs to be fixed first. The allowable draw is way too much. That s a disaster just waiting to happen. An electric range if used normally requires a 50AMP source and rated receptacle and plug.
 
(quoted from post at 08:07:21 10/15/14)
All this aside you got bigger fish to fry. Your 100 amp sub panel with all those breakers and fed by only a 10/2 wire which is rated for 30 amps needs to be fixed first. The allowable draw is way too much. That s a disaster just waiting to happen. An electric range if used normally requires a 50AMP source and rated receptacle and plug.

Maybe, maybe not. Code may not allow it but if the 10/2 feeder circuit is protected by a 30 amp overload device it doesn't matter what the load rating of the sub-panel is. If the sub-panel draw ever exceeds 30 amps the overload device will disconnect the loads at the main panel. No different than plugging too many devices into the receptacles on 15A branch circuit.

TOH
 
(quoted from post at 09:32:08 10/15/14)
(quoted from post at 08:07:21 10/15/14)
All this aside you got bigger fish to fry. Your 100 amp sub panel with all those breakers and fed by only a 10/2 wire which is rated for 30 amps needs to be fixed first. The allowable draw is way too much. That s a disaster just waiting to happen. An electric range if used normally requires a 50AMP source and rated receptacle and plug.

Maybe, maybe not. Code may not allow it but if the 10/2 feeder circuit is protected by a 30 amp overload device it doesn't matter what the load rating of the sub-panel is. If the sub-panel draw ever exceeds 30 amps the overload device will disconnect the loads at the main panel. No different than plugging too many devices into the receptacles on 15A branch circuit.

TOH

Very true and I agree. But I read and reread his thread about the sub-panel. Maybe I don't see it where it is stated that he is running a 30 amp main. I assume since he said it was a 100 amp sub that he is running a 100 amp main.

I see that he has 3-15 amp, 1-20 amp and 1-40 amp breaker in that sub panel. If he is running a 30 amp main which I assume is at the main panel, then he can potentially overload the 10/2 wire back to the main panel with a 40 amp breaker in the sub. The 30 amp at the main will blow before the 40 amp at the sub on an over draw.

Also if 10/2 is used to feed the sub than I am assuming 10/2 was used to feed the 40 amp breaker in the sub. Again a potential for an over draw.
 
(quoted from post at 09:01:43 10/15/14)
(quoted from post at 09:32:08 10/15/14)
(quoted from post at 08:07:21 10/15/14)
All this aside you got bigger fish to fry. Your 100 amp sub panel with all those breakers and fed by only a 10/2 wire which is rated for 30 amps needs to be fixed first. The allowable draw is way too much. That s a disaster just waiting to happen. An electric range if used normally requires a 50AMP source and rated receptacle and plug.

Maybe, maybe not. Code may not allow it but if the 10/2 feeder circuit is protected by a 30 amp overload device it doesn't matter what the load rating of the sub-panel is. If the sub-panel draw ever exceeds 30 amps the overload device will disconnect the loads at the main panel. No different than plugging too many devices into the receptacles on 15A branch circuit.

TOH

Very true and I agree. But I read and reread his thread about the sub-panel. Maybe I don't see it where it is stated that he is running a 30 amp main. I assume since he said it was a 100 amp sub that he is running a 100 amp main.

I see that he has 3-15 amp, 1-20 amp and 1-40 amp breaker in that sub panel. If he is running a 30 amp main which I assume is at the main panel, then he can potentially overload the 10/2 wire back to the main panel with a 40 amp breaker in the sub. The 30 amp at the main will blow before the 40 amp at the sub on an over draw.

Also if 10/2 is used to feed the sub than I am assuming 10/2 was used to feed the 40 amp breaker in the sub. Again a potential for an over draw.

The question of what size breaker he has in the main panel was never addressed but certainly should be. And I don't know if code allows you to use a reduced capacity feeder like that.

Of course he can create an overload condition at the shed just like I can do by shorting out a lamp cord at my house. But [u:f1190c6d7f][b:f1190c6d7f]if[/b:f1190c6d7f][/u:f1190c6d7f] the feeder circuit is protected at 30A (or smaller) NOTHING connected at the sub-panel can "overload" the feeder OR any additional downstream 10 gauge wiring. It does not matter what size breakers are in the sub-panel - they could be 200A and it wouldn't matter. The [b:f1190c6d7f][u:f1190c6d7f]instant[/u:f1190c6d7f][/b:f1190c6d7f] (or close enough) the draw on the feeder circuit exceeds 30A the main panel breaker disconnects the feeder and the sub-panel with all of it's breakers and loads. The sub-panel and it's attached loads CANNOT "overload" the feeder circuit.

I actually had a similar setup in my shed for several years. I ran a 10/2 above ground feeder from a 30A breaker in my house mains to a 100A sub-panel in the shed, I put the 100A panel in because I wanted to wire multiple circuits in the shed and had plans for burying a 100A feeder in the future. It took juuuust a little longer than I planned but ultimately the 30A feeder got upgraded to 100A ;-) It only lasted a few years before it got torn out when the big shop got built :roll:

TOH
 

I think we are both saying the same but said differently.
I have installed many 100 amp subs and a few 200 amp subs. And yep you have to match the main breaker to the feeder cables and branch circuit breakers to the branch wiring.

My Dad was religious about the fact that he couldn't care what you were going to do in the future. He was was going to wire you up based on what you were capable of running at the moment.
You could either wait to upgrade or call him back when you were ready to do the entire job correctly.
 

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