220 to 110 wiring question

Reply

  #1  
Old 04-23-09, 11:09 AM
Member
Thread Starter
Join Date: Jan 2008
Location: Texas
Posts: 123
Received 0 Votes on 0 Posts
220 to 110 wiring question

The wire running from my load center to my 1.5 hp 220v water well pump is 10/2 w/ ground, i.e., it doesn't have a neutral wire.

I want to take 110v off of either the contacts on the pump side of the pressure switch or in the control box, so that I can have a 110v circuit with a single outlet box that is only hot when the pump is running. The circuit will be used to power a 110v AC to 12v DS wall wart, which will be input to a relay.

So...my question is how do I get a neutral conductor to to the outlet box, or do I need one? If not, exactly how is the outlet wired?

In case it makes any difference, the circuit breaker for the well pump is in a subpanel that has a floating/non-bonded neutral.

Thanks,
Ira
 
Sponsored Links
  #2  
Old 04-23-09, 11:57 AM
ray2047's Avatar
Member
Join Date: Mar 2006
Location: USA
Posts: 33,597
Received 13 Votes on 11 Posts
Use a relay with a 240v coil instead of a low voltage coil and wall-wart. Run the relay coil off the pump contactor. If you tell us what the relay will control someone may have an even better idea.
 
  #3  
Old 04-23-09, 12:49 PM
Member
Thread Starter
Join Date: Jan 2008
Location: Texas
Posts: 123
Received 0 Votes on 0 Posts
I already have the relay, so I would rather use it.

I know the way I'm doing it sounds kinda wierd, but using a plug-in wall-wart also allows me to easily remove voltage to the relay (it's a wall mounted, self-contained/enclosed relay) without having to shut down the well pump or remove the wires running from the pump switch or control box.

Ira
 
  #4  
Old 04-23-09, 12:55 PM
ray2047's Avatar
Member
Join Date: Mar 2006
Location: USA
Posts: 33,597
Received 13 Votes on 11 Posts
You would need to change the two conductor wire to your pump to three conductor wire. That to me seems a lot more work and cost then just using a relay with the right size coil. You can always turn off the relay with a switch.
 
  #5  
Old 04-23-09, 01:02 PM
Member
Join Date: Sep 2000
Location: United States
Posts: 18,497
Received 0 Votes on 0 Posts
my question is how do I get a neutral conductor to to the outlet box, or do I need one?
Yes you need one. The only way to get one it to run one.

Overcurrent protection is also an issue. You need the right level of overcurrent protection. You didn't say what size the breaker was so we have no way to tell with the information we have now.
 
  #6  
Old 04-23-09, 01:11 PM
Member
Thread Starter
Join Date: Jan 2008
Location: Texas
Posts: 123
Received 0 Votes on 0 Posts
Originally Posted by John Nelson View Post
Yes you need one. The only way to get one it to run one.

Overcurrent protection is also an issue. You need the right level of overcurrent protection. You didn't say what size the breaker was so we have no way to tell with the information we have now.
It has a 20 amp breaker.

It's actually pretty easy to run wire thru the conduit to the pump house. Can I just run a single 12ga. wire from the neutral bus to the wall outlet?
 
  #7  
Old 04-23-09, 01:12 PM
Forum Topic Moderator
Join Date: Feb 2005
Location: Near Lansing, Michigan
Posts: 10,944
Received 42 Votes on 40 Posts
It has a 20 amp breaker...Can I just run a single 12ga. wire from the neutral bus to the wall outlet?
It has to follow the same path as the hot, but yes that is what is needed.
 
  #8  
Old 04-23-09, 02:02 PM
Member
Join Date: Sep 2000
Location: United States
Posts: 18,497
Received 0 Votes on 0 Posts
It has a 20 amp breaker.
That's good. It eliminates that issue.
 
  #9  
Old 04-23-09, 02:23 PM
Member
Join Date: Apr 2004
Location: Ontario Canada
Posts: 1,767
Received 0 Votes on 0 Posts
One option is to find a power supply that can run off of 240V, and plug into a 6-20 receptical, or get a 240V to 120V transformer.
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes
 
Ask a Question
Question Title:
Description:
Your question will be posted in: