Electrical Wiring Question

Nice,
I have a friend that found a wired up extension cord in his wall when he was remodeling his house. The stuff people do....

 

I was doing a job in a hospital and found some romex ran through conduit. Needless to say , I was quite surprised.

 

I wish I could say I haven't.

I've pulled runs of wiring out of old Greenfield, only to find chunks of lamp cord TAPED onto the end because the wire was too short to make the run.

Here is one of the more "interesting" installations I discovered...

 

C'mon dude, do you really need the sheathing on such a short run?

 

Wow, I also liked the non accessible junction box.

 

LMAO, I'm only reminded of my good friend Steve-O at the track trying to fill up his tires with my air tank.

Steve: "What the hell, is this thing on reverse?"
Me: "No dumbass, it's not on the valve correctly"

 

Sounds like you have everything taken care of. I'm also a big fan of twist-lock connectors for high-power loads and for things like compressors and other tools where if the plug comes loose or falls out, things can get dangerous/difficult. That would be a L6-20P / L6-20R
Twist-Locks are required on construction sites here in Chicago for that reason.

Dear God!

Can't say I haven't found the same. Also, renovation contractors love to cover up junction boxes with drywall, plaster, or simply mud. Nothing like hunting down a run with a problem and discovering there's a junction box you can't get to without hacking into the ceiling or wall.

 

I will start off by saying this is totally my fault, but I had the compressor running for about 30 seconds and went to close the water drain and got zapped. So I shut everything off and pulled the cover off of the switch box where the wire was going into the compressor and found that the white wire was going to ground and the green and black wires were going to the motor. I thought green was supposed to be ground and white was supposed to be marked with black tape and was a hot wire in a 220 system. Anyway, I got that straightened out and all was well, but that is the exact reason I double checked what I was doing on here.

 

You got more problems than that.

If the motor was properly grounded, but through the wrong conductor, the breaker should have tripped from a direct short to ground.

Also, if the motor was running on 120v and you're wired for 240v, you should have noticed a very weak motor start and it may have damaged the motor. Before you run it again, check the placard on the motor for wiring schematics for 120/240v installations.

 

Once I switched the two wires everything seemed to run fine, so I think I got away without damaging the motor. However, what you said about grounding has me concerned. There are only three connections on the compressor itself. Two for the power wires and one for the ground. I have the two power wires connected to the breaker and the bare ground wire connected to one of the grounding bars in the breaker box. What checks should I do to make sure i have it grounded properly now (other than the obvious that I don't get shocked). Is it possible that there is a diode in the system that kept the electricity from flowing from the ground to the motor?

 

Like Darren said, look for and check the rating plate which is mounted directly to the motor.

It will tell you if this is really a 120V motor or a 120/240V motor or a straight 240V motor, and also it will indicate how to wire the motor connection terminals. Better yet, take a pic of said rating plate and post it.

If you have a standard pressure-switch driven compressor, you've been looking in the switch connections. Take a look at the MOTOR.

 

Ok, I checked the name plate on the motor again. Unfortunately it is difficult to see and I don't think I could get a clear picture of it. It says 208-230V, 15A, singe phase. There is also a wiring schematic that shows three wires, one labeled "L1 or Black," one labeled "L2 or White," and one that simply says ground. The L1 and L2 are shown going to the motor the ground is shown outside the motor going to ground. So in the switch box the black and white wires from the motor are attached to the contact terminals and the green wire is connected to a ground plate (I have no reason to believe that these have been changed since it came from the store). Coming from the breaker box, my black wire is connected to the terminal that goes with the black wire from the motor and the white wire from the breaker box is connected to the terminal that goes with the white wire from the motor. The bare wire is connected to the terminal bar in the breaker box that goes to the ground wire going outside and the other end is connected to the ground plate in the switch box that the green wire from the motor is connected to. I think I have it right. Am I missing something, or are there any continuity or voltage checks I could do to make sure? It did run fine yesterday. It filled the tank and cycled a few times while I was using the impact wrench.

 

Ok, time to dig this one back up. So, now that it is getting colder out and I have lots of work to do in the garage this winter I am looking for a way to get some heat out there. I am thinking of getting this http://www.northerntool.com/shop/tools/product_200362124_200362124

but I am thinking I would need a 30 amp circuit for it. A 20 amp 240 volt circuit is good for 3600 watts right? Would 4000 watts overload it too much?

 

Maximum load on a circuit is 80% of it's rating.

So 240V @ 20 A = 4800W x 0.8 = 3840 Watts max. The heater is listed at 4000 watts. While it will likely not trip the 20A breaker, if I were installing it, I'd use #10 wire and a 30A breaker.

You might be better off with a propane heater.

 

Thanks. That is pretty much what I thought but I couldn't remember the % for calculating the maximum load. I am really looking for something just to warm it up to sweatshirt temperature. I looked at Kerosene first, then propane second and electric third. Forced air Kerosene heaters are not cheap enough. Propane probably is really the best choice, but I would rather not have anything that actually has a flame. Probably the biggest reason I am thinking electric is there is a virtually unlimited supply of energy right there in the wall. No running out of propane when I am at a point in a job where I can't leave to get more. I will probably get a 3k watt 240V electric forced air heater. This would be a whole lot easier if the person that built our house had put natural gas in.

 

Depending on your locale, that heater may be completely satisfactory, or totally inadequate.

I just got this, http://www.northerntool.com/shop/tools/product_200485167_200485167 , for occasional use in the garage. With the temp in the 20's recently it warmed it to mid 50's in about 10 minutes. This is a non-insulated 2.5 car garage. That was with 60k btus of heat. I am wishing I went with the 75k model.

Electric is plentiful, but EXPENSIVE when used. Saw the energy bills for an electric Sauna, scary with minimal use. Enjoy your heated work space.:up:

 

I looked at that exact propane model too and really considered it. I am in southern Ohio and am attempting to take the chill off of an R19 insulated attached 24X24 garage. I doubt I will be able to heat the garage with it, but I am thinking it should at least warm it up. I do realize it won't be quick but it should help. If not I can get the propane to heat it up and use the electric to maintain it. I did the math and including all of the fixed charges I pay roughly 10 cents per kilowatthour, so a 4k watt heater should cost me roughly 40 cents per hour. If I work out there and have the heater on full blast for 10 hours thats $4, so not too bad. Propane around here is roughly $1 per pound, so overall the electric should be cheaper. Per BTU propane would be a bit cheaper. I calculated 29 cents per 10,000 btu per hour for electric and 23 cents per 10,000 btu per hour for propane at 10 cents per kilowatthour and $1.00 per pound of propane.

I ordered the electric one today so I should find out sometime next week.

 

I HIGHLY recommend you hire a legitimate, licensed electrician before you kill yourself and your family.

 

I have a very similar one in a 14x24 1 car workshop. Wired it with a 30amp Breaker and #10 wire. My garage has R13 walls and r38 ceiling. The ceiling is where I was losing all of my heat. Now I keep the temp at around 45-50 degrees out there all the time and never have to change out the water wetter in the race bike. :up: When I go out to work I turn it up and its 65 degrees in there in no time. YMMV

 

Man the truth is, doing renovations some times it's easier to rip it all out and start over!