Electrical questions

Electrical questions · 10-03-2009, 08:46 PM

One more coat of paint and I can start wiring! A couple of questions:

(1) To wire the fluorescent lights, I plan to run the wire in EMT conduit to a strategically located box on the ceiling, and from there use 3/8" flexible aluminum cable ("fixture whip"). Since I will use the EMT conduit as the ground (vs. running a separate wire), I believe I have to add a ground wire at this point. Does that wire need to have green insulation, or can it be a bare wire?

(2) Does a ceiling box _have_ to be octagonal? I believe it can be square, but I'm having a hard time finding a reference. Side question - what's the advantage of having an octagonal box to begin with?

(3) Is there a place where I can buy 10 gauge solid wire? The BORGs and Ace only sell it stranded? I can order it online, but I only need 50ft.

Skymaster · 10-03-2009, 09:40 PM

Square boxes are normally Junction boxes, octagonal boxes normally are fixture boxes because the round bases will cover the oct box. Also there is more room in square for wires to be joined whereas normally to a fixture there is only one or two wires if things are in series. IMHO
For grnd wire bare will do just make it a very solid connection. Stranded wire will work fine, actually better than solid since it is way more flexible.

scsmith42 · 10-03-2009, 09:53 PM

Originally Posted by Bas

One more coat of paint and I can start wiring! A couple of questions:

(3) Is there a place where I can buy 10 gauge solid wire? The BORGs and Ace only sell it stranded? I can order it online, but I only need 50ft.

Personally I prefer stranded; however the best local place that I know of for electrical supplies is City Electric Supply (CES). They have several local branches; I use the one in Cary. They sell wire by the foot so you only have to buy what you need.

Douglas Robinson · 10-03-2009, 10:19 PM

Bas:

I have a large roll off wire I used to wire my shop. Large grade my electrician friend recommended.

Gotcha6 · 10-03-2009, 11:12 PM

(1) To wire the fluorescent lights, I plan to run the wire in EMT conduit to a strategically located box on the ceiling, and from there use 3/8" flexible aluminum cable ("fixture whip"). Since I will use the EMT conduit as the ground (vs. running a separate wire), I believe I have to add a ground wire at this point. Does that wire need to have green insulation, or can it be a bare wire?

The fixture whip, (aka MC cable) if connected properly to the EMT and the fixture, will act as a grounding device. No other grounding is required beyond this method provided the EMT is connected properly from the panel box to the fixture or device.
As for switches & receptacles, you will need to use a grounding screw & pigtail (green wire) to the device. These are available ready to go from the BORGs.

Bas · 10-04-2009, 11:02 AM

Originally Posted by Skymaster

Stranded wire will work fine, actually better than solid since it is way more flexible.

I only have to go 20 feet or so, with one 90 at the end, so in my case flexibility isn't that important. But yeah, I looked at some 10 gauge solid wire and that stuff is tough...I would not want to pull that around 3 or 4 bends.

Originally Posted by scsmith42

Personally I prefer stranded; however the best local place that I know of for electrical supplies is City Electric Supply (CES). They have several local branches; I use the one in Cary. They sell wire by the foot so you only have to buy what you need.

Thanks Scott!

Originally Posted by Douglas Robinson

I have a large roll off wire I used to wire my shop. Large grade my electrician friend recommended.

Expect a PM coming your way. I've been meaning to come check out your shop and ooh and aah over your J/P, now I really I need to get my behind in gear!

Originally Posted by Gotcha6

The fixture whip, (aka MC cable) if connected properly to the EMT and the fixture, will act as a grounding device. No other grounding is required beyond this method provided the EMT is connected properly from the panel box to the fixture or device.
As for switches & receptacles, you will need to use a grounding screw & pigtail (green wire) to the device. These are available ready to go from the BORGs.

That makes sense Dennis. To clarify, I'm making my own fixture whip using the MC cable and wire. The premade armored cable I saw at the BORG had a separate ground wire, which is why I assumed that was needed. But that's probably because some people will connect it to PVC (NMT).

I think I have every connector, screw, cover plate, strap and fitting I need at this point

BTW, I saw something at Home Depot I had not seen before, grounding clips. You stick the ground wire in the clip, then slide the clip over the box wall. No screw. I suppose the cover plate will hold the clip in place, but I've never seen a box wired that way before.

Thanks for the help everyone.

Skymaster · 10-04-2009, 12:21 PM

Bas; tension and friction hold those grounding clips to the side of the box. I am not an electrician but have done a bit and I never got comfortable with them. I believe in a really tight connection either wire nutted or to a grounding screw, I dont like loose grounds :}:}

DaveD · 10-04-2009, 03:16 PM

For the #10 solid you can go buy it in romex/nm form and just strip off the outer cover

jlwest · 10-04-2009, 04:44 PM

You must have some big equipment. 10 gauge will do 30 amps or enough to do a electric stove. I'm curious as to what you are running on the circuit.

Jeff

Bas · 10-04-2009, 10:56 PM

Originally Posted by Skymaster

I believe in a really tight connection either wire nutted or to a grounding screw, I dont like loose grounds :}:}

Same here. They were marked down from $7 to $2 for 100, but even at that price I just couldn't see myself securing the ground wire. I've never had a connection come loose (knock on wood) and I'm not about to start either!

Originally Posted by jlwest

You must have some big equipment. 10 gauge will do 30 amps or enough to do a electric stove. I'm curious as to what you are running on the circuit.

Well, so far - nothing

! But I'm looking to upgrade pretty soon. One of the items I'm considering is the G0441 dust collector, which draws 22 amps @ 240V. The rest of the equipment should run just fine on 20A circuits, but you never know what you run across. This will save me some time rewiring if I do need 5HP, all I'd have to do is swap out the breaker.

jlwest · 10-05-2009, 09:10 AM

That is a lot of amps at 240v. Grizzly has traditionally used Chinese motors which are notorious power hogs because of the cheap copper they use in the windings. That will be one nice dust collection system. Did you check out Onieda? Probably more initial cost but cheaper operational cost.

Jeff

jrevans · 10-05-2009, 06:25 PM

Originally Posted by Bas

One of the items I'm considering is the G0441 dust collector, which draws 22 amps @ 240V.

That's a heck of a lot of power for a "3HP" dust collector. 22A @ 220V = 6.5HP!

McRabbet · 10-06-2009, 01:33 PM

A ClearVue CV1800 Cyclone is equipped with a Leeson 5 HP motor that draws 20.8 Full Load Amps. I'm using #10 wire on a 30 Amp breaker and a 30 Amp contactor for the on/off control for mine.