electrical question

[randy41]

the cable is 10/2 and the suggestion to install a sub-panel in the greenhouse seems to be the easiest solution. do you guys think the frost free hydrant i have in the greenhouse would be a suitable ground?
i did all the wiring in my house so i have electrical work experience. how would i use a disconnect box to do this that is different than using a sub-panel? is it wired the same way but the equipment is cheaper?

 

[ray66v]

I believe I already answered these questions.

If you have 10/2, 220 volts, you have no neutral wire. Unless your planning to run one, you should stop.

Whatever your using for a sub panel, needs to have the grounds, and the neutral wires isolated from each other, rather than connected, (bonded), together as they are at the main panel.

The only thing considered a suitable ground, is a properly driven, (as per code in your area), ground rod.

 

[tommu56]

I believe I already answered these questions.

If you have 10/2, 220 volts, you have no neutral wire. Unless your planning to run one, you should stop.

Whatever your using for a sub panel, needs to have the grounds, and the neutral wires isolated from each other, rather than connected, (bonded), together as they are at the main panel.

The only thing considered a suitable ground, is a properly driven, (as per code in your area), ground rod.

I second the vote you are setting your self up to get shocked
Electrician for 30 years
tom

 

[hitekcountry]

I strongly recommend you not violate the electrical code, It is very much designed around safety. I've seen things that were done that do work but that are very unsafe. It isn't hard to do the job correctly.

 

[ray66v]

I second the vote you are setting your self up to get shocked
Electrician for 30 years
tom

It's nice to have someone agree.... for a change.

 

[Iplayfarmer]

I have to concur with the others if you have 10/2 wire. There's no good way I know of to wire it without a neutral. Like Hitekcountry suggested, there are ways that will work, but it's not a good idea. Your options at this point are...

1) Follow Craig's advice and run a whole new 120 volt line to your greenhouse. (I'd recommend using 12 gauge wire so you have the option of a 20 amp circuit.)

2) Run new 10/3 wire and do the subpanel idea.

3) Re-configure your heater to 120 volt and run the whole circuit out there on 120 volt. (This depends on how much heat you need and whether your heater is convertable.)

If it were me I'd just run the extra wire for a separate 120 volt circuit.

 

[ruralNearDallas]

I have a similar situation running to my barn. We ran 10/3 with ground in UF. I would have run 6 or 8, but we got a great deal on the 10/3.

We will be putting a panel out there, soon.

We also have a 30A breaker protecting the UF and the barn.

Remember, the breaker protects the downstream equipment.

One issue you will have: I can't find a 110V receptacle that will accept 10 guage wire. You will need a pigtail or something to convert.

Also, each leg (not technical, but I am going to talk color) will allow 30 amps. That means the red will do 30 and the black will do 30. If the heater is really drawing 23 on 220, then both the red and black are already using 23A. Note that the label is for the maximum, not what it truly does.

That means you can have two 110V circuits that can supply 7A per--assuming the heater is running and drawing 23A.

Also, I certainly agree with the other posters who like the sub panel idea.

Also, I agree with the person who said that sometimes appliances are expecting to be protected with a 15A breaker, so they could burn up using your original plan. Solution: buy an inline (comes in various ways including power strips and extension cords) 15A breaker.

I hope I helped.

By the way, I am planing to go with the flexible conduit with wire already in.

 

[ray66v]

One issue you will have: I can't find a 110V receptacle that will accept 10 guage wire.

My understanding is, you can't legally put 30 amps, to a normal 20 amp duplex receptacle.

However, I do occasionally use #10 wire on them, I have never seen a receptacle that would not allow a #10 wire on the screw terminals. Which is the only way you should wire one.

 

[mmurphy]

It's nice to have someone agree.... for a change.

There is others who agree with you.

My question is, why not run another circuit to the green house?

 

[tommu56]

I have a similar situation running to my barn. We ran 10/3 with ground in UF. I would have run 6 or 8, but we got a great deal on the 10/3.

We will be putting a panel out there, soon.

We also have a 30A breaker protecting the UF and the barn.

Remember, the breaker protects the downstream equipment.

One issue you will have: I can't find a 110V receptacle that will accept 10 guage wire. You will need a pigtail or something to convert.

Also, each leg (not technical, but I am going to talk color) will allow 30 amps. That means the red will do 30 and the black will do 30. If the heater is really drawing 23 on 220, then both the red and black are already using 23A. Note that the label is for the maximum, not what it truly does.

That means you can have two 110V circuits that can supply 7A per--assuming the heater is running and drawing 23A.

Also, I certainly agree with the other posters who like the sub panel idea.

Also, I agree with the person who said that sometimes appliances are expecting to be protected with a 15A breaker, so they could burn up using your original plan. Solution: buy an inline (comes in various ways including power strips and extension cords) 15A breaker.

I hope I helped.

By the way, I am planing to go with the flexible conduit with wire already in.

as long as it is 10/3 with ground (4 wires) and on a double pole breaker this is OK.
If you put it on the same leg the neutral could be loaded with the sum of the total current.
After seeing many neutrals burnt up after some one rearranged the panel and put both wires on the same leg I always recommend separate neutrals.

tom