Electrical question

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tattooedfreak

Steel mutilater is more like it.
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Mar 12, 2010
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I posted on here a few weeks ago about my motor and received a number of helpful responses but based on what I would have to do, I held off and tried to think of another way to do it. I have a 50a outlet in my shop that was used for a kiln by the previous owner, the rest of the outlets are only 15a. While the shop was made specifically for a clay worker, I doubt that any of the outlets are wired with 12g wire so it isn't feasible to swap an outlet for a 20a outlet. My 1hp motor is currently wired for 120v but draws 13.8a at its peak, this tripped the breaker at my old shop but doesn't trip it here (well, at the one outlet I tried) that doesn't mean it would trip once I started putting load on it. Responses to my original question gave spot on advice to swap out the 50a breaker for a 20a and just run the motor off that. My issue comes as the pigtail I need to use is for an oven and has 8g wire making connection to the switch I have extremely difficult. Also, if I wanted to use an oven or kiln in the future, I would continually have to swap out the 20a and 50a breaker.

My thought was to use the pigtail and wire it to a 60a sub (pony) panel and put in a double 20a (for 220v) a single 20a (120) and a single 15a (120). This would effectively make a sub panel with 3 breakers and enabling me to just unplug it and run an oven off the original 50a (when I get one). I would then wire each breaker with appropriate wiring and plug ends for the particular motor or equipment I was using at the time. I was at the local hardware store and ran it by the guy in the electrical section and he said it would work but he isn't sure about code. I'm not really worried about code as it would only be plugged in when I was using the outlet and actually in the shop.

My question is (finally, I know) while it sounds good in my head and to the guy at the store, is it doable and safe? It seems as if it should act like a sub panel and as long as I keep the usage below the 50a main it should be fine but I'm not an electrician. Oh, the breaker is a 50a double 220v, my main panel is a 200a panel and has no extra spaces or I would put another breaker in. Thanks.

sean
 
I guess the question is what is your panel in the shop? You do not mention it, only your 50A receptacle. You might also pull a face plate off and check to see what gauge wire you have running to the 15A receptacles. Depending on how old it is, it very well might be 12ga. A lot of people buy the 15A receptacles despite having 12ga. wire. This would be my first step. If you don't have 14ga wire and do have 12ga., just swap out your receptacles and replace them with 20A recep's. Also if this is the case be sure to swap out the breakers as well to 20A.

If you do have 14ga wire and the 15A receptacles are fine for most of your work, you could put in external conduit with a few steel 4x4 boxes, i.e. one that holds two sets of receptacles, around the shop walls. This might be a good option if you don't want to pull wire to the existing receptacles.

Just something to think about.

Greebe
 
What you need to do is install a sub panel. Install a sub panel. Take out the 50amp breaker and Install a 100amp breaker in its place. Then out of the new sub panel run 10 wire to a new rec to where you want it but install a spec 20amp rec instead of a normal one.
 
richard thurman said:
What you need to do is install a sub panel. Install a sub panel. Take out the 50amp breaker and Install a 100amp breaker in its place. Then out of the new sub panel run 10 wire to a new rec to where you want it but install a spec 20amp rec instead of a normal one.
Click to expand...

I like yours better... that is how we would do it at work but it would require a small amount of electrical know how.
 
richard thurman said:
What you need to do is install a sub panel. Install a sub panel. Take out the 50amp breaker and Install a 100amp breaker in its place. Then out of the new sub panel run 10 wire to a new rec to where you want it but install a spec 20amp rec instead of a normal one.
Click to expand...

So, take out the 50a outlet and install a sub panel instead? That defeats my purpose of leaving the outlet to use an oven later.

Grebe, I don't have a panel in the shop and putting in the panel would allow me to swap my motor out to 220v (instead of 120 as it is now) and to use other equipment that requires 220 but less than 50a.
 
Your 50amp plug in sub panel will work fine. Totally safe. Make sure your sub panel is grounded. Is the 220v/50amp outlet a three prong or four prong.
 
Your 50amp plug in sub panel will work fine. Totally safe. Make sure your sub panel is grounded. Is the 220v/50amp outlet a three prong or four prong. Also check the breaker at the main panel that feeds the 50amp outlet. I think you said it had 8 gage wire which means it is probably a 40amp circuit. Keep in mind a circuit breaker is only meant to carry 80% of its rating under continous load.
 
Odog27 said:
Your 50amp plug in sub panel will work fine. Totally safe. Make sure your sub panel is grounded. Is the 220v/50amp outlet a three prong or four prong.
Click to expand...

Sorry my mistake, 40a and it is a four prong oven outlet used for a kiln and I have the pigtail to go with it.
 
So,you are golden! By pigtail I assume you are talking about the cord and plug off the kiln. Make sure it is also 8 gage wire. If it is factory you should be fine. Use that to feed your sub panel. Wire appropriately from the sub to branch circuits. Unplug and use 50 amp plug when needed. Not exactly code but perfectly safe.
 
richard thurman said:
What you need to do is install a sub panel. Install a sub panel. Take out the 50amp breaker and Install a 100amp breaker in its place. Then out of the new sub panel run 10 wire to a new rec to where you want it but install a spec 20amp rec instead of a normal one.
Click to expand...

the bad thing about this is breakers are not only there for safety reason of the house but also to protect your equipment and you always want your breaker to pop before you kiln pops lol going to a 100amp breaker probably not a good idea unles you are always running a lot of stuff :)
 
Your plan is fine. Sure, re-wiring the existing fuse box with a sub-feed, and the shop with new wires and outlets would be a permanent solution, but making a plug-in sub-panel is also a viable solution.

The set-up would go like this:
Existing 50Amp/220 VAC socket.
Pig-tail from new panel box. The plug will match the existing outlet.
New small breaker box with breakers as stated.
Wiring from breakers to new receptacles.

All wiring should be of a gauge suited to carry the current of the breakers:
Pig tail should be 8 gauge.
Wiring to receptacles should be 12 gauge.
All wiring from the new box should be run inside the walls or in conduit.
All circuits and boxes should have grounds. Assure that the ground to the existing outlet is functional.
 
Thanks guys, Stacy that is exactly what I was thinking. This is only a temp solution for now, when I eventually get the money, I plan on upgrading my main panel and at that time I will upgrade the shop wiring a little as it is right beside the room with the panel. Thanks again for all your input.

sean
 
tattooedfreak said:
So, take out the 50a outlet and install a sub panel instead? That defeats my purpose of leaving the outlet to use an oven later.

Grebe, I don't have a panel in the shop and putting in the panel would allow me to swap my motor out to 220v (instead of 120 as it is now) and to use other equipment that requires 220 but less than 50a.
Click to expand...
your sub pannel is going to have more than one breaker slot in it. just install another double pole breaker for your oven
 
chad2 said:
the bad thing about this is breakers are not only there for safety reason of the house but also to protect your equipment and you always want your breaker to pop before you kiln pops lol going to a 100amp breaker probably not a good idea unles you are always running a lot of stuff :)
Click to expand...
the 100 amp breaker is a main to feed the new sub pannel. in the sub pannel you put the right breaker to feed your gear.
 
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