Electrical Conduit- what's the code?

[BigguyZ]

I'm running new electrical to my kitchen. Currently, all of the power for my kitchen, my living room, a bedroom closet and my bathroom are all on the same circuit! I have plenty of free spot on my panel, so I want to run at least two new lines to the kitchen when I rennovate.

As far as I know, the fridge needs to be on it's own circuit. Can anyone confirm this? If so, should I have one more circuit for the dishwasher, disposal, oven (gas), range hood (non-vented, recirculating), and the 4 or so outlets? That seems like a lot on one circuit (though comparitively it isn't). Or, would you say fridge, disposal, and dishwasher is OK on one circuit and the rest on another? Or do I need three lines added there? I'm fine going with three new lines, But I don't want to do so unless it's necessary.

Also, I'm running these new lines up a floor. I was told that romex is fine in conduit for a short run and that THHN isn't necessary for only 12 fee or so. Is that correct? And with 2 or 3 lines, what size conduit am I looking at? I got 1/2", but I'm thinking that's going to be a bit too small if I run three lines, and close for two lines...

Thanks!

[woodturner]

I was told that romex is fine in conduit for a short run and that THHN isn't necessary for only 12 fee or so.

My advice is to go to your local library and read the relevant sections of the NEC. It should only take you an hour or so and you will be able to answer your own questions. In addition, read any local additions to the NEC.

Why do you want to run NM-B in conduit? Is there a local requirement that you use conduit?

You may want to consider hiring a licensed electrician - your NEC questions are very basic and suggest you may not have the experience to do this work safely.

[BigguyZ]

My advice is to go to your local library and read the relevant sections of the NEC. It should only take you an hour or so and you will be able to answer your own questions. In addition, read any local additions to the NEC.

Why do you want to run NM-B in conduit? Is there a local requirement that you use conduit?

You may want to consider hiring a licensed electrician - your NEC questions are very basic and suggest you may not have the experience to do this work safely.

The new lines are going from the basement to the second floor. I'd rather not open up walls to run the NM-B in them, so I figured I'd do a run of conduit where it goes through a closet, right next to the water and gas lines that are run in the same way.

I have the skills to do this safely, I'm just not familiar with code when it comes to conduit specifically. Most of my wiring has been with accessable areas, so it hasn't been necessary.

Anyways, if someone who knows could answer, that's be great, as I don't have much free time in my day to try to find the right information in the NEC.

Thanks

[LJR]

Kitchens require the most circuits of any room in the house. Each kitchen is required to have two 20 amp appliance circuits to feed the counter top receptacles only (NEC 210.52). Those are calculated at 1,500 VA each, therefore 1,500VA x 2 = 3,000 VA. (NEC 220.82)

Other loads in the kitchen are electric range, typical 7,500 VA (each range is different, all ranges will have a name plate with the maximum load specified in Watts which can be as high as 15,000 watts or VA). Dishwasher, typical 1,200 VA, clothes washing machine, typical 1,500 VA, clothes dryer, typical 5,000 VA. (NEC 220.82)

A separate 20 amp circuit is needed for the refrigerator and if you have one of those whole house central vacuums installed, that should be on its own 20 amp circuit as well. (NEC 220.82) Those two loads are 1,500 VA x 2 = 3,000VA. Those circuits are heavy loads. Other appliances that require separate circuits are garbage disposal, built in microwave oven, trash compactor, stand alone freezer, and anything with a 1/2 HP or bigger motor. When they are run on separate circuits it will prevent circuit breaker trips and dimming lights when the appliance turns on.

As far as running the romex inside conduit, yes it is possible - but. Romex has to be installed in such a manner that it is protected from physical damage. If you put it in conduit you satisfy that requirement, however your conduit fills up very quickly and you run into a problem of not having enough space in the conduit, especially if you are thinking of future runs.

If I were doing it I would:
1. Fish the romex in the wall. There are fish tapes and long drill bits available and techniques that don't require taking the drywall off or cutting holes in it.
2. If fishing a wall isn't possible I would go ahead and do the conduit run. Run the romex to a junction box. Run conduit from that point to another junction box, run THHN in the conduit and then run romex from the second junction box out to the desired locations. Remember that junction boxes have to be left accessible.

[BigguyZ]

Kitchens require the most circuits of any room in the house. Each kitchen is required to have two 20 amp appliance circuits to feed the counter top receptacles only (NEC 210.52). Those are calculated at 1,500 VA each, therefore 1,500VA x 2 = 3,000 VA. (NEC 220.82)

Other loads in the kitchen are electric range, typical 7,500 VA (each range is different, all ranges will have a name plate with the maximum load specified in Watts which can be as high as 15,000 watts or VA). Dishwasher, typical 1,200 VA, clothes washing machine, typical 1,500 VA, clothes dryer, typical 5,000 VA. (NEC 220.82)

A separate 20 amp circuit is needed for the refrigerator and if you have one of those whole house central vacuums installed, that should be on its own 20 amp circuit as well. (NEC 220.82) Those two loads are 1,500 VA x 2 = 3,000VA. Those circuits are heavy loads. Other appliances that require separate circuits are garbage disposal, built in microwave oven, trash compactor, stand alone freezer, and anything with a 1/2 HP or bigger motor. When they are run on separate circuits it will prevent circuit breaker trips and dimming lights when the appliance turns on.

As far as running the romex inside conduit, yes it is possible - but. Romex has to be installed in such a manner that it is protected from physical damage. If you put it in conduit you satisfy that requirement, however your conduit fills up very quickly and you run into a problem of not having enough space in the conduit, especially if you are thinking of future runs.

If I were doing it I would:
1. Fish the romex in the wall. There are fish tapes and long drill bits available and techniques that don't require taking the drywall off or cutting holes in it.
2. If fishing a wall isn't possible I would go ahead and do the conduit run. Run the romex to a junction box. Run conduit from that point to another junction box, run THHN in the conduit and then run romex from the second junction box out to the desired locations. Remember that junction boxes have to be left accessible.

Thanks! This helps. I was trying to avoid the cost of buying THHN, but If you think that makes sense that's what I'll go with.

It sounds like I'll need at least 3 lines. It's a very small kitchen, so there's only going to be four receptacles. I think then one line for the fridge, one for the wall outlets, and one for the future dishwasher/ disposal.

Thanks!

[master53yoda]

The code since the 80's has required 2 GFCI circuits for the receptacles in the kitchen. You have said that you will only have 2 receptacles. You could put 1 circuit that would hit one receptacle and the fridge. The other could hit the other recedptacle. If it was me I would use double gang boxes provideing 2 resceptacles per location. If you anticipate a a dishwasher or garbage disposal run a separate circuit to them. A dishwasher and a coffee pot could very well trip a breaker. the same with a frig and a coffee pot or electric frying pan. Both the Refrigerator and the dishwasher use electric heaters that are close to a full circuit load by them selves.

Romex- should only be run in conduit for about 5 ' max due to heating inside the conduit.

You said that there was piping etc in the back of the closet. Run the Romex along side the piping and then get a sheet of the 3/16 or 1/8" paneling and box in the corner. If its boxed in with the paneling it provides the protection that the code requires and can be accessed latter for additional work

Please bear in mind that watts and VA are not the same thing. VA is the rating of inductive loads (Motors) and the votage and current are not in phase with each other. Watts is the rateing of work (heating elements) and is normally produced in heat . The watt formula is I squared R or Volts x amps x power factor.(power factor varies with the inductive load between as low as .05 and 100%.) The VA formula is Volts x Amps and does not take into consideration the inductive loads.

[woodturner]

Anyways, if someone who knows could answer, that's be great, as I don't have much free time in my day to try to find the right information in the NEC.

With respect, if you don't have time to learn the correct way to do the work, you don't have time to do the job safely. To do electrical wiring safely requires reading and understanding NEC.

That's why I didn't answer your question - I don't want you to hurt or kill yourself, and don't want to be a party to that.

[tseavoy]

Your question is what does the code say regarding (metal) conduit. My answer is that I don't know. I could go to my Sears Practical Wiring book (c. 1960) to see what it says.
In my experience there are two classes of home wiring -- inspected, where current code compliance is necessary, and uninspected, where deviations may be taken as long as they are safe. In fact, for old work deviations are often allowed by code.
Here are some observations with an opinion or two thrown in.
1. My refrigerator draws 3.5 amps and is on a household lighting circuit. I see no reason to change.
2. The two required kitchen circuits can be wired so that one circuit powers the top receptacle of duplex receptacles and the other circuit powers the bottom. This is done by cutting out the jumpers between top and bottom.
3. A dishwasher requires a separate circuit, especially if it one using an electric heater for drying. Mine doesn't but still has its own circuit.
4. My shop (uninspected) has NM wire run in 1/2" metal conduit mostly.
5. Kitchen GFI requirement is a new one on me. When I wired my house GFI was only required for bath and outdoors. No big deal I guess since GFI breakers are not all that expensive nowadays.

No recommendations here, just observations.


Tom on Marrowstone

[crokett]

What is code is whatever the inspector in your area says it is. So if you truly want to know what code is, call your inspector. If this isn't getting inspected, then as was said, there are ways to do it safely that don't quite meet code. The problem is 'safe' is different for everybody.

In your case I would put the fridge, disposal and dishwasher each on their own circuit and have 2 circuits for the appliances. The only one I'd consider sharing is disposal and appliance outlets. As far as running the cabling, I would use PVC conduit and not metal, that way you don't get into grounding issues. I have a quick and dirty fill calculator that says 3/4" is minimum for what you need. Since grounds take up physical space, I would go with 1" to make it easier to pull. I would do romex or NM to a junction, conduit and THHN to another junction then romex or NM the rest of the way.

[woodturner]

In my experience there are two classes of home wiring -- inspected, where current code compliance is necessary, and uninspected, where deviations may be taken as long as they are safe.

There is a small but non-zero chance that uninspected wiring will cause problems down the road, no matter how well it is done.

The two areas where typically people run into issues if they did uninspected work are:

1. Insurance claims - house burns down, insurance company wants proof of inspections, denies claim if not provided. Had a friend who had this experience. Eventually won, only because the insurance company realized continued ligitation was going to cost more than settling.

2. When selling the home, the buyer's inspector notes the absence of inspections and the buyer asks for proof of inspections. Most savvy buyers will now ask for this - and the agents know to advise them to ask. If the inspections cannot be produced, the work must either be removed or inspected. If inspected, there may be fines as well, and work may have to be redone. Worse yet, the seller is now "on notice" and can't sell the house to someone else without disclosing and remedying the defect.

P.S. IANAL and this is not legal advice

[crokett]

There is a small but non-zero chance that uninspected wiring will cause problems down the road, no matter how well it is done.

There is a small but non-zero chance that inspected wiring will cause problems down the road, even though it was inspected.

Insurance companies insure stupidity. Everybody has a 'friend' who was denied coverage. This might actually have happened to your friend. At work there is an eclectic bunch of folks on my team. One is a former insurance agent. I asked him about uninspected work a while back and his answer was that insurance companies insure stupidity. Taking off my moderator hat for a moment, and asking as a simple member of this forum, please don't trot this out again. I hear this on every DIY forum I am on and have yet to have anyone state that it happened to them, personally. I'm not saying don't get it inspected, I'm saying I've never met anyone who was personally denied coverage because of uninspected work. It was always a friend. In a city here a few years ago, a guy was doing plumbing with no permit and didn't have a backflow preventer on his house. He backfed bacteria into the city water. Water was shut down for several hours. He had to pay fines and costs of city finding the contamination source, but guess what? His insurance co paid at least the cleanup costs.

My county requires a permit for replacing a water heater. Do you suppose that a) the average homeowner really knows this or b)if it is done without a permit and something happens coverage will actually be denied?

Like I said, what is deemed acceptable risk is different for everyone. So the OP needs to make his own determination.

[BigguyZ]

Thanks for all of the replys everyone. I wanted to avoid the cost of buying THHN for the conduit, but it sounds like that's the way to go. I don't want to bother with making a vertical shroud around the wiring or anything, as it's in a closet of my renter and I don't want to bother her more than necessary.

And I'll say this- I'm no electrician, but I think that 90% of home wiring can be done safely by a homeowner as long as he or she knows what they're doing. If I pulled a permit, I'd need a certified electrician to do the work because Minneapolis is insane when it comes to permits and inspections. And I can't afford that. However- what's more dangerous- me leaving the electrical over-loaded as it was when I bought the place, or updating the wiring for the kitchen to that it's done as-close-to-code as possible?

And in general, I agree that a LOT of inspections are subjective. There was some work that was required by the city prior to my buying the house (with plumbing). The seller had the work completed, and it needed to be re-inspected. I tried to ge the same inspector back in to sign off on it, but I got another inspector instead. As a result, the new inspector added a half dozen things that she felt needed to be fixed. Of course, the plumbing works perfectly fine and it's all arbitrary. But it's still something I'll have to go through if I ever want to sell the place... But as it is, the city's a bunch of incompetent morons who get/take/steal enough of my money as it is. I have no intention on involving them in updating my place.

Again- thanks everyone for the help!

[phi1l]

But what do you really think?

[BigguyZ]

But what do you really think?

What? Are you saying I'm a little bit opinionated? ME?

BTW, I dropped by Menards last night and picked up some 12 gauge solid THHN. I opted for the 3/4" conduit, as non the the boxes has a knock-out for a 1" line. Now the fun begins!