How much romex in 2" PVC conduit from 1st floor to 2nd floor?

Thanks JW.

And yes, LED lighting is for real IMHO. I like the new Cree bulbs sold in some HD stores. My entire bedroom now uses less than 25 W with everything on max. By insulating, putting in a new furnace and windows, LED lighting, etc, I've cut my power and gas usage by about half -- and have a more comfortable environment.

When it comes to a workshop, more is better -- to a point. The average usage is actually quite low, but the peak can be high...

Steve Zerby said:

In these older houses it is often impossible for me to run a skilsaw and and anything else at the same time (dust-collecting vac, halogen work lights, compressor plugged in and happens to kick on while I'm making a cut on the chop saw, etc, etc.) I've made far too many trips to the fuse panel. And virtually every tool I use now has to be connected to a dust-collecting HEPA vac for the lead paint rules.

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I have been doing electrical contracting work for over 44 years and have yet to see a saw service installed for the construction of a home that would carry every electrical tool on the market today.

It is not a case of installing a circuit big enough to handle all these tools at one time but it is instead a matter of managing the tools being used at one time.

Any dust collector of any size to control lead dust should always be on its own circuit with no other tool. Should your air compressor be of any size at all it also should be on a circuit of its own and not shared with any other motor load.

A half horse power 120 volt motor for a tool when just running and not cutting will draw ~ 10 amps but lock the motor and it will draw ~ 59 amps. In order to start the motor to turning without any load at all it will for a nanosecond draw 59 amps.

Knowing this and then trying to saw while a dust collector and air compressor is plugged into the same circuit is doing nothing but burning out the motors.

It is not a matter of bigger circuits but a tool management problem. Do the math to see for one self just what motor tools do. Multiply the full load amps by 6 to see what the maximum amp draw of the motor will be. A 1/3 hp motor draws 7.2 FLA (full load amps) a ½ hp draws 9.8, a ¾ hp draws 13.8 and a 1 hp draws 16 amps. You will find they draw a LRA (locked rotor amps) of 43.2, 58.8, 82.8, and 96 amps respectfully. To check my numbers one can reference Tables 430.248 FLA for 120 volt motors and 430.251(A) LRC of the NEC.

Installing a larger circuit just so we can operate two or more of these appliances at one time just means that there is more heat energy available when we have other problems.

Edited to add:

It has also been my experience that shop tools just don’t do very well plugged into a 15 amp circuit. It is illegal to use the general purpose circuit of a home for renovations purposes unless the tool being used if protected by a GFCI device.

I don’t know of the times that I have been called by a remodeler to look at the circuits in someone’s home because the breaker kept tripping during construction. A smart contractor will have a temp service installed for any remodel work instead of trying to use the premises wiring of the home they are working on but alas it continues to be done none the less.

Should you try to use the premises wiring for your tools then learn how to manage the tools being used at one time and the problem will diminish

JW, thanks for stepping in there and explaining the drawbacks of 20 amp circuits as general lighting circuits. I just don't explain it the way you do.

Steve, sorry if I sounded snotty, but I did say I was confused, and then you acknowledged that you were joking. I have seen several 1000 sqft bungalows from the '40s have a second story put on them, a standard sized lot around here is 6000sqft and often it makes more sense to go up. But I know that the floor must be torn out and all the foundations reinforced. So if you want to joke about going to a third floor, you will trip me up.

Back to your concerns about load demand. Yes, once upon a time 60 amp services with four fuses were common in the bungalows around here. I have replaced a few of them, but there are not many that were not updated decades ago. And those updates are getting replaced.

But efficiency is king. You were positing the demand of dozens of halogen lights. And now you acknowledge that LEDs are available and obviously are more efficient.

The CURRENT code demands that you provide 3 va per sq ft, which works out to 42.5 amps, in general lighting circuits. You don't get to round down.

So you can install three 20 amp circuits and deliver 60 amps, or three 15 amp circuits and deliver 45 amps, or take my advice, and put in four 15 amp circuits and have 60 amps available, which is about 30% over the minimum requirement. Quicker, cheaper, easier, and as JW illustrated, SAFER.

And shop around for some more efficient TVs please, the ice caps are melting. While you are wiring the room, you can put a switch on the wall that turns off all the power to the entertainment "vampire" load. That stuff is deadly on your electric bill. There is no need to have it on when it is not in use, is there?

You mentioned the idea of a new kitchen addition. When I work up such a project, I assume six circuits or so. Two 20 amp counter circuits. A 20 amp dedicated circuit over the stove for the inevitable microwave range hood (my inspectors really push that one, and I don't currently push back). The garbage disposal and dishwasher get another dedicated 20 amp circuit, and both of them have cords that plug into an outlet, that is the latest code.

The refrigerator I always put on a dedicated circuit when working from scratch, why not? 15 amp is sufficient unless it is big enough to hang sides of beef in.

If the laundry is anywhere near by, it gets a dedicated 20 amp circuit. And the lighting for the kitchen is on none of the circuits described.

On one occasion it made sense for me to just put in a 50 amp subpanel for the whole kitchen, that ended up saving lots of wire. Most of the time, the original plan has the service panel near the kitchen for obvious reasons, so that was the exception. What you describe may be another exception.

Sorry, duplicate

bluebinky said:

Thanks JW.

When it comes to a workshop, more is better -- to a point. The average usage is actually quite low, but the peak can be high...

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Obviously, a workshop is a horse of another color compared to the general lighting circuits in the house.

My experience has been that a 30 amp service feeding four 20 amp circuits gets the job done for most of my clients.

Many guys are pretty optimistic about how much time they are going to be out there and how many tools they are going to run.

JW is quite right: a dedicated circuit for the dust collector, another for the air compressor, another for the various power tools that one is only going to be working one at a time anyway, another for the AC, and find some way to get lighting in there.

The AC can be 240v, which helps balance the load down the service feed.

Or make it 40 or 50 amp. I'll deposit the check all the same.