Workshop Subpanel Amps

[Fly-by-Night CC]

And DL when you get to the point of installing new lighting, do a newsgroup google search with Lew's name as author - I followed his advice and am quite pleased with the brightness in my shop.

[DL]

Duane,

I will have to get the information on the brand (I think S&S) for you as it is stored currently while I am doing the buildout. The unit has a 7.5hp Baldor motor that I purchased based on an original thought that I would purchase older 3-phase equipment and restore it for use in my workshop since I am unable to get 3-phase service. Primary reason for this one was capacity and price. I bought it used in ebay for a good price IMO.

I am rethinking the need for the rotary phase converter at my current location. Having a somewhat longer term goal to move where I should be able to get the 3 phase power brought in directly into a dedicated workshop building, I will hold off on purchasing anymore 3 phase equipment. For the

3 phase lathe I have, I am strongly considering moving to a variable frequency drive that will convert the single to 3 phase, thus obviating my current need for the phase converter at all. The rotary phase converter I have not is way over spec for the lathe alone, but wouldn't be for a 7.5hp DeWalt RAS or other larger machinery that I want to delve into at some point.

David

[DL]

Thanks, it is next on my list...

David

[Doug Miller]

I'm sorry, but that's not true, not completely, anyway. No, it doesn't require a professional to install aluminum wire [and I did not say that it did], but it *does* require special knowledge, if not special skills, and tools that are not in the average homeowner's toolbox.

To install aluminum safely, connections must be coated with anti-oxidant compound. This is not necessary with copper. And not everyone knows about the difference.

Lugs holding aluminum wire must be tightened to a specific torque. Too loose, and the wire arcs, or comes out - but too tight, and it cold-flows away, and arcs. Again, not everyone knows this. And the average homeowner does not have a torque wrench in his toolbox.

No, it's *not* "just a connection". It's a connection that needs to be made with substantially more care than connections involving copper wire. And not everybody knows this.

I never said that the average homeowner was not *capable* of possessing the requisite skills and knowledge. I do claim, though, that the average homeowner possesses neither those skills, nor a torque wrench.

I'm not trying to make mysteries out of anything. Just pointing out that installing aluminum wire correctly is not as simple as installing copper wire correctly - and since *any* incorrectly installed wiring presents potentially lethal hazards, Joe Homeowner is better off using copper simply because it's harder to screw up.

-- Regards, Doug Miller (alphageek at milmac dot com)

Nobody ever left footprints in the sands of time by sitting on his butt. And who wants to leave buttprints in the sands of time?

[Duane Bozarth]

...

OK, thanks...it's been a low-level "onna-these-here-days" for some time now. I want the shop in the barn loft and would like a couple larger pieces such as a 4-side moulder and thickness sander that could be in the present shop area where the low ceilings aren't such an issue...haven't found that bargain as yet (but haven't really searched seriously yet, either)...

If one should wander off to SW KS sometime and were in need of a home, I'm sure something could be arranged... :)

[DL]

I agree with Mike that it is not a overly complex connection to install as long as someone has the proper knowledge, tools, and respect for the potential dangers of not doing it correctly. I also agree with Doug that the are inherent issues with the Al connection that don't arise with the copper installation. When I added an addition on our old house, I needed to redo a significant amount of the wiring the previous owner did when he added a small addition on the house because it was installed wrong.

Also, the fact that I would need to go to #00 Al to get the same load capacity, it as the #2 copper, going with the cooper will just be easier to handle when I am routing the cable from the main to the subpanel.

It's great to know that I am not an average "Joe" homeowner. Not only do I have a torque wrench and know how to use it, I have three of varing sizes :D

David

[Backlash]

Dang, Lew, I've got ONE welder I'm gonna install that the data plate says requires a 95 amp circuit.......One of the best things I ever did was install a 200 amp main just for my one man shop.

RJ

[Electric Stu]

I installed a dedicated subpanel for my shop when I built it a couple of years ago. I did a fair amount of research in preparation for the shop wiring and ended up using a 10/20 125amp Siemens panelboard with a copper bus. I had only a 10 foot run from the main service panel to the subpanel. The electrical supply store I went to had 25' of already cut

2/3 w/ground copper that someone never picked up, so he gave it to me for 40 cents/foot and he threw in a 90 amp DP breaker, so that's what I used (even though the ampacity of the cable conductors is much greater). I installed ten branch circuits using 12/2 w/ ground NM cable with 220V and 110V Twist-Loc receptacles (Hubbell - ridiculously cheap @ $2.50/each by the box on eBay at the time) generously spaced around the shop for flexibility in tool placement. Next to each Twist-Loc, I also installed conventional 110V receptacles (industrial grade Hubbell's, once again dirt cheap on eBay). I installed industrial fluorescent T8 electronic ballast fixtures as well, divided into two zones, controlled by 3-way switches at each of two doors. There are both 4' and 8' dual bulb fixtures with a total of 22 4' bulbs. I made certain to wire the lighting into the main panel on its own 20A circuit instead of into the subpanel, so the lights wouldn't go out if the subpanel breaker tripped (e.g., while I was ripping a narrow piece of maple). All in all, I used about 600-700' of 12/2 NM for all of the wiring, but it came out beautiful and works like a charm.

To minimize accidental use of any tools by unauthorized people (i.e., kids), I habitually flip off the subpanel breaker in the main service panel when I'm finished in the shop.

I did make sure that I pulled appropriate permits and had everything inspected, not because I wasn't confident in my wiring skills, but for insurance reasons, in the event of an unexpected catastrophe. The electical inspector turned out to be a woodworker, so for the rough inspection, he spent more time talking to me about woodworking than actually inspecting. He said he normally scruntinizes homeowner's wiring, but said the wiring job was better than most professional jobs he inspects. We both agreed that this likely relates to the attention to detail inherent to woodworkers.

Good luck.

Stu

[Brian Elfert]

I installed 100 amps, but I doubt I'll ever need that much. I could envision the 220V dust collector, 220V Unisaw, and the 220V air compressor all running at once, but they would take 40 amps or less.

My local Home Depot has wire plenty big enough to handle 100 amps. It is THHN and has to be run in a conduit. I used three seperate wires to feed my subpanel.

Brian Elfert

[Lee Cobb]