View Full Version : Hard Wire or Pig Tails

03-07-2004, 08:12 PM
I am having the local electric folks put in a new 100 amp service to my shop, this is 220VAC single phase. Should I hard wire the power into the machines or just have pig tails? Three 220 vac circuits in the shop will be machine dedicated, while one be pig tailed for my welders and cutters.


03-07-2004, 08:39 PM
What I did,

I set a distribution panel, put breakers for each machine, ran romex circuits for each.

My welder table is a roll around. I put a arm on the back and a roll of cable. I plug in the welding table, the 4 conductor cable feeds a box in the table, a 120 circuit breaker allows a small drill press or grinder to be plugged in to the table. I also have a 12 inch brake mounted to the table and two vises. It is grounded. I know this cause a VSR drill shoots a spark to it.

The roll around welding table is the best way to take the mig, gas bottle, vise, and stick machine to the welding.

My mill, I recently moved it again. I have another distribution panel fed off a 50 amp breaker in the first panel, it has the 3phase convertor wired into a breaker. Turning on the breaker feeds the 3rd phase to a isolated bar. Setting 2 pole breakers for each 3 phase motor, (cheap) and the 3rd leg wires direct to the bar.
Really works well. the more motors that are running the smoother it gets since one feeds the others, each smoothes the wave. Label the inside of the box, the outside and still tell anybody else who works in the box. WHile the 3 phase motors are running it is hot. Stupid people think the extra bar is a neutral or ground bar.

I'd at least put conduit drops to the machines and run the romex down it. *(if you are running romex) if not run pipe. Emt is easy to run. PVC is easy..

Line of sight is the ruling on the local dissconnects on the machines. If you can see the breaker box, well that is alright.

My shop is pretty small. I wish it was larger.


03-07-2004, 08:56 PM
We wired my garage with romex and then had to rip it all out. Would have been ok if I didn't have to have an inspection when I had a separate meter for the garage (200amp service). Code required either metal or plastic pipe on exposed wiring, and since the garage isn't finished in... it was easier to just rip it out and replace it with plastic pipe,etc
The upstairs is still wired in romex since the inspector didn't bother to climb the stairs to see if I redid that part.
David from jax

03-07-2004, 09:15 PM
I am planning on using 6-3 wire inside plastic conduit for the internal wiring to the machines and 12-3 for anything else that is 120 service.

Mike P
03-07-2004, 09:39 PM
It's a good idea to wire a recepticle for each machine and actually plug the machines into the wall, or floor, or post mounted outlet. This lets you have a certain disconnect, at the machine, that no-one will power up by accident.

I know we're mostly in our shops by ourselves, but safety first!!

As a side note...Since I have an older house with a 100 amp service for the whole house, I've got one, 30amp, 220 single phase outlet in the garage. It's a four wire (two hots, neutral and ground) that has a three prong outlet right next to it with a 2' long pigtail coming out of the bottom. the pigtail has a four wire plug on it that plugs into the four wire outlet.

When I want to run the welder or lathe, I plug the machine into the three wire plug, then plug the pigtail into the 4 wire outlet. If I want to run the phase converter to run the mill, I plug it's four wire plug right into the 4 prong outlet on the wall. (The three proger can't get power, because it's unplugged from the 4 wire outlet).

Farmer Joe
03-07-2004, 10:28 PM
Put in the biggest pannel you can to have the most circuits. You can have a 200 amp pannel fed by only 100 amp. At Home Depot, a Square D 40 circuit 200 amp plus Breakers is only around @ $130. You'll need extra circuits for inside lights, outside lights, heat, radio, refridgerator, welder, work lights, battery charger, engine block heater, power washer.....

03-07-2004, 10:42 PM
Ditto Farmer Joe!

If you don't have recepticals at each machine, you'll need shutoffs. Recepticals are cheaper.

By the way, why only 100amp service?
It doesn't take long to use that up. Compressor, Heater, Air Conditioning, Exhaust Fan, Wife's new Freezer, ... Won't leave a lot available for tools.

03-07-2004, 10:45 PM
The lighting and the frig are already wired to the main house circuit. Where my compressor, the 3 new machines and a couple of other things need to be independent.

I do plan on using a large box and will wire each machine on a separate breaker.

I do know safety is first and fore most, that is why I am asking these questions.

03-07-2004, 10:47 PM
It is my understanding that the electrical code requires every machine to have a disconnect within a certain range of the machine. A plug meets the requirement for a disconnect and that is usually less costly than a disconnect blade switch. We have it both ways. Fused disconnects on air compressors and vacuum pumps, plugs on drill presses, bridgeports and small lathes. Straight unfused 100 amp disconnect on welding machine.

J Tiers
03-07-2004, 11:25 PM
AS IBEW says, running EMT is easy. I think it is easier than PVC stuff. And there is the advantage that it is tougher against silly things that tend to happen. (and easier to change later. Way easier)

I don't know what you mean by "pigtailed", but I wouldn't think you had anything that couldn't be plug connected.

At our old woodshop we had everything on drops from a busway, but that was for overall convenience, not because the stuff wasn't mostly plug connectable. (The CNC router wasn't pluggable....)

03-08-2004, 01:02 AM
In canada, by law, pigtailing is hardwired, if this is dione they have to have an emergency power disconnet switch near the equpment for safety reasons that can be locked out by a padlock this is in the NEC. Other wise the equipment must be on code sized CSA certified disconnects (plugs & outlets).

I do not know what US code requires.

03-08-2004, 01:03 AM
A pig tail is the cord from a machine or an appliance that goes to an outlet. Such as your dryer has a cord to the wall out let, some have different prong shapes or placements.


J Tiers
03-08-2004, 09:47 AM
<font face="Verdana, Arial" size="2">Originally posted by Thrud:
In canada, by law, pigtailing is hardwired,
I do not know what US code requires.</font>

So your radios are hardwired to a box by law? Electric shavers too?

New TV, call the electrician?

I am obviously missing something here. What's wrong with a properly rated plug and socket?