New subpanel?

Printable View

04-11-2009, 06:51 AM
Zenman

New subpanel?

In the near future I'm planning to add some electric to my soon-to-be workshop in the basement which is about 50 feet away from the main panel (new 200 amp panel). I have a bunch of toys... um... I mean tools. Your basic wood working tools plus an arc welder and my wife's kilns... They all run on 110v, but who knows maybe I'll get some 220v tools soon. ;)

So my question is; is it worth installing a new subpanel in my workshop or run several new lines as needed from the main panel? How many amps for the subpanel? Also what type of wire and\or conduit would be needed to be run to the subpanel?

Thanks!
04-11-2009, 07:08 AM
jwelectric

First if you are going to be doing a lot of cutting and sanding in your basement lets hope you have one hell of a dust system.

Second if you are planning on welding where there is a lot of wood dust in your basement let’s hope and pray that you have one of the best homeowners insurance polices out there.

Third the size of the remote panel will depend on the load imposed.

Fourth the method in which you wire this remote panel is a design issue.

I hope I have helped in some way but with the information given it is the best I have to offer.
04-11-2009, 07:26 AM
Zenman

1. Dust collection system is planned.

2. Actually I haven't done any welding in the past 20 years, but thought I should mention it since I still have it.

3. I guess I should figure out the maximum number of tools\appliances that could actually be running at the same time. For now lets just say one lighting circuit, and four 20 amp circuits all (possibly) being used at the same time. (lights, sump pump, dust collector, table saw, kiln)

4. Yes, this is the main question, wire type and design.
04-11-2009, 10:01 AM
jwelectric

Quote:

Originally Posted by Zenman

1. Dust collection system is planned.

Not just a dust system but a damn good dust system. Remember you are in your house and wood dust is flammable.

Quote:

Originally Posted by Zenman

2. Actually I haven't done any welding in the past 20 years, but thought I should mention it since I still have it.

Again wood dust is flammable.

Quote:

Originally Posted by Zenman

3. I guess I should figure out the maximum number of tools\appliances that could actually be running at the same time. For now lets just say one lighting circuit, and four 20 amp circuits all (possibly) being used at the same time. (lights, sump pump, dust collector, table saw, kiln)

This would have to be known in order to give you any more information. It is very possible that you will exceed the limits of your service which could mandate a new service

Quote:

Originally Posted by Zenman

4. Yes, this is the main question, wire type and design.

This would by your choice. You are the only person that can answer this question
04-11-2009, 10:29 AM
Zenman

OK thanks, I'm just in the planning stages and wont start on this for a while. I'm just trying to figure out costs right now, and comparing different options. Once I spec out a dust collection system I will be better able to define the loads. I do have another question if you don't mind...

The cable will be run inside the basement, and assuming the subpanel will be 100 amps. Which type of cable can I use - NMB or do I need SE or ...?
04-11-2009, 12:59 PM
jwelectric

The amount of money you have to spend on the project will determine the methods used.

Personally I would install aluminum SER (4 conductor) cable as it will be the cheapest method and just as safe as any other.

On a side note, I did a little shop for a friend a few years back and he ended up having to do a service change from a 200 to a 320 continuous to accommodate the equipment he installed. After his kilns and turn tables were added with the lighting his service wasn’t large enough for the added loads. He also added heat and AC to this area which was a fairly large load. This was an expense that he wasn’t expecting and almost stopped the installation. When I eat supper tonight I will be eating from one of his plates.

As far as finding what the project will cost all you have to do is get a couple of electricians to bid the job. Just because you get a bid doesn’t mean they have to do the work and you will have the estimated cost of the installation.
04-11-2009, 02:10 PM
Zenman

That sounds like good advice. I will get some electricians in for a bid or two. But first I need to get all my loads figured out. I'm good on heat and A\C. Thanks again.
04-11-2009, 02:49 PM
jadnashua

Many of the motors on stationary tools can operate at either 110 or 220vac with an internal wiring change and a proper plug. I'd consider making those changes - the tools tend to run cooler and thus last longer.
04-12-2009, 07:03 AM
killavolt

Code changes now require sub panels to have their own ground rod(s) seperate from the main load center (panel). If you have enough room in your new main load center run it from there. 12/2 and 14/2 wire is pretty reasonable now and you can get at least 4 homeruns with a 250' roll of wire.
04-12-2009, 07:36 AM
Zenman

Thanks Killavolt - I know a subpanel has different rules than a main panel (ie separate neutrals and grounds...) but the separate grounding rod is news to me... What (code) year was that instituted? I wonder if my town has adopted that code.

Since I have room in the main panel, its starting to look like that will be cheaper and easier up front, but possibly less convenient down the road - like if I ever wanted to add a new circuit in the workshop in the future. It will be more work and money up front to add the sub panel especially if I need to add a grounding rod.

I definitely will have to make a list of all the pros and cons.

Oh and Jadnashua, thanks for your input too.
04-12-2009, 08:45 AM
jwelectric

Quote:

Originally Posted by killavolt

Code changes now require sub panels to have their own ground rod(s) seperate from the main load center (panel). If you have enough room in your new main load center run it from there. 12/2 and 14/2 wire is pretty reasonable now and you can get at least 4 homeruns with a 250' roll of wire.

Do What??????????? Which code????

Can you show this in the NEC????????

Just Where did this come from????????

What if each load is 80 feet from the panel, can you still get four home runs from one 250 foot roll?
04-12-2009, 09:58 AM
killavolt

Quote:

Originally Posted by jwelectric

Do What??????????? Which code????

Can you show this in the NEC????????

Sorry, read the question too fast. Ground rod is not needed if main panel and sub are in the same building or attached like a garage.

Just Where did this come from????????

Quote:

Originally Posted by jwelectric

What if each load is 80 feet from the panel, can you still get four home runs from one 250 foot roll?

You don't have a wire stretcher? The OP said the location was about 50 feet from his load center. I was just coming back to correct this when you posted.