Help with 220V Ceiling drops

[Frank Trinkle]

I am in the middle of completely updating my woodshop. New tools, new house, dedicated three-car 960SF garage for my shop.
Next in the long line of tasks is the electrical system. The original owners of the house clearly used the garage for only cars and it is severely lacking outlets...and no 220V.

I am getting ready to pull the trigger with a highly rated electrical contractor to install 15 110V outlets, both wall mounted and ceiling mounted (for lights and air filtration system). Then adding 9 220-240V outlets. One dedicated to a 3HP Cyclone DC, another dedicated for an HVAC system to be installed later in the spring. The others can share breakers as only one machine will operate at a time.

I want to install four 220V ceiling drops on 10-3 wire to power my machines central in the workshop. I seem to remember seeing a thread that had pictures of how some of you have done it...safely...but I can't find the thread(s). Obviously, 10-3 is heavy, and I plan to use twist locks, but I would love to have some recommendations and pictures of how you mount from the ceiling, and what products or mods you use to secure the outlets. I want to get with my contractor and show pictures of what I want, and would greatly appreciate the help any of you can give.

Final note. We WILL be pulling permits from the city, and will be subject to inspection, so whatever solutions are offered will have to meet Florida specs.

Thanks in advance for any suggestions.

Frank

[Michael W. Clark]

Hi Frank,
I remember the thread you are referencing but I am no good with the search. Seems like SO chord and strain reliefs were used.

Do you need/want 10-3 or will 10-2 work (should be much less expensive)

If you have/plan for an Air Compressor, you may want to consider a dedicated circuit for it since it can run at any time.

[Frank Trinkle]

Hi Frank,
I remember the thread you are referencing but I am no good with the search. Seems like SO chord and strain reliefs were used.

Do you need/want 10-3 or will 10-2 work (should be much less expensive)

If you have/plan for an Air Compressor, you may want to consider a dedicated circuit for it since it can run at any time.

I plan for 10-3 throughout. I know 10-2 is cheaper, but some machinery will require 10-3 and I'd rather not mix. Ultimate safety is the primary consideration as well, not cost.

As for compressors, I will be primarily using air for a simple blower, and pin/brad nailing with some of my glue-ups. I have a 110V, 20gallon Kobalt Oil-less that is loud as hell, but once filled, it's pretty much done for the day for my needs. Additionally, I'm buying a super-quiet Rollair JC-10 that may ultimately replace the Kobalt due to my very limited air requirements.

Still looking for Ceiling drop options and suggestions.

[Dan Blackshear]

Maybe contact these people http://www.reelcraft.com

It's a pricey solution but very slick and would easily pass code I'm sure.

Looking at their site I would think maybe this one http://reelcraft.thomasnet.com/item/...0-5000/l-7000? but it may be overkill.

[Michael W. Clark]

You are right, if you have some machines that require the 3rd conductor, it is better to have it and not need it, than to need it and not have it. That's the same reason I ran a separate circuit for the A/C. Currently, I have a 1HP older unit, but will want/need to upgrade in the future. It was much easier to run the service with all the electrical work than trying to retrofit later with a shop full of equipment.

You may already be doing this, but put your lights on their own circuit(s). A tripped breaker from an outlet put you in the dark. If you put them all on one circuit, at least use more than one switch to operate them. This way you can isolate part of them for maintenance if necessary and still have some light.

This is an example of what I recall others using for the strain relief.
http://amtecgrips.com/products/strai...d-nps-fittings

You probably also want a twist-lock plug suitable for the ampacity and conductors. I used a 30A twist-lock 4-prong for my 3ph TS connection. Good thing you are not concerned about the price, as they are not cheap, but are definitely worth it in the right application.

Mike

Edit:
Maybe a more accessible supplier.http://www.mcmaster.com/#cord-grips/=ok6gnb

[Rick Potter]

I kept mine simple, and installed twist lock plugs in the ceiling with short extension cords hanging down, and twist locks on the ends of those. It has worked fine for 7 years so far, and if I am not using one, I can just unplug it at the ceiling till needed.

Rick Potter

[Buck Williams]

Probably the most cost effective strain relief is something like this
http://www.amazon.com/Arlington-LPCG...cord+connector

A rubber grommet tightens around the cord jacket and insures that your cord is not hanging by the copper conductors. You'll have to size the grommet range to your 10/3 cord (10/3 is correct, in rubber cord the "3" refers to 2 conductors and a ground). You can Google the cord diameter for 10/3 SO cord to find the proper diameter for the grommet. The connector will probably require a 3/4" knockout to attach the end opposite of the cord to the box in the ceiling.

[Phil Thien]

I kept mine simple, and installed twist lock plugs in the ceiling with short extension cords hanging down, and twist locks on the ends of those. It has worked fine for 7 years so far, and if I am not using one, I can just unplug it at the ceiling till needed.

Rick Potter

That is probably how I'd do it. I'd actually eliminate the short extension cords and run a longer cord on the tool right up to the box on the ceiling. I'd kill the power at the breaker for blade changes, etc.

Of course, if you plan to frequently move tools, the short extension cord probably makes a lot of sense.

[Jim Andrew]

Before he moved, my neighbor was an electrician, so I got advice from him on how to do the wiring in my shop. For 220 drops, he said to put a box in the ceiling, and buy a piece of heavy cord, cut it the right length for my hanging plug, and tie a knot in it and put the knot in the box with the cord hanging down.

[David L Morse]

P1060774_M.jpg
Crude? Perhaps, but not random, some thought has gone into this. The loop doubles the cable where the tie wire wraps around it helping to prevent a tight bend. The tie wire is 12G Copper and holds the cable with friction. A tug of more than about 50lb opens the tie wire and allows the straight blade plug to disengage. To me anything hanging from the ceiling that could get tangled in material or some body part is a safety hazard without the breakaway feature.

[John Lifer]

The problem with putting box with outlets in ceilings (except for lighting) is that if you you want to disconnect the plug, you have to get up on a ladder. I put box and dropped cords down. Used a cable to relieve the strain.

[Scott T Smith]

I kept mine simple, and installed twist lock plugs in the ceiling with short extension cords hanging down, and twist locks on the ends of those. It has worked fine for 7 years so far, and if I am not using one, I can just unplug it at the ceiling till needed.

Rick Potter

This is how I did my shop as well.

In commercial facilities that I have been in, the Amtec strain reliefs referenced by Michael is the accepted norm.

[Charles Lent]

The kellems type cord grips are the only strain reliefs that, the electrical inspectors that I've worked with, will accept for pendant type drop cord strain reliefs. Knots tied in the cord, the clamp type strain reliefs and other home brew forms of strain reliefs are not acceptable for ceiling drops. Ask your inspector what he wants to see before you start.

Having a 100 amp sub panel installed in your shop to supply all of the 120 and 240 volt requirements of the shop would be the best way to go. Multiple long 12 ga wire runs to the main house panel can frequently cost more to install and will not allow flexibility for unforseen new tool installations in the future. A 100 amp 240 volt panel (get the one with the most breaker positions) should be more than adequate for any one person woodworking shop and a new tool would only require wiring back to this panel. I would install a sub panel in the shop even if the main house electrical panel was located on the other side of the wall, because it separates the shop circuits from the house circuits.

Charley

[Ethan Melad]

for my 220 and 3-phase drops, my (former) electrician used ceiling mounted junction boxes that had clamps built in/fitted to the knockout where the cord came through. he used a heavy cord; then a hook to give it some slack (i think the hook is actually a clamp so the cord wont slip). I have some fitted with outlets and some with female plug ends. The cords also have "chinese finger toy" strain relievers at both ends. Now that I'm writing this, it seems like overkill...but seems to work well.

[Michael Dunn]

I just had some 220V ceiling drops installed by professional electricians. They installed boxes and had strain relief drop them down. I believe they were water tight connectors with a rubber bushing that compresses around the cable.