20A 240V Service Conversion from 40A 240V

Reply

  #1  
Old 07-20-16, 04:37 PM
Member
Thread Starter
Join Date: Jul 2016
Location: North America
Posts: 4
20A 240V Service Conversion from 40A 240V

I am converting a 40A service to a 20A service and keeping the 240V. Now somepne please chime in or tell me if I may be doing something unsafe. Thank you.

As far as I know, from a lot of knowledge and readings, I need to switch out the 40A dual slot breaker with a 20A dual slot breaker, cap the neutral on the wall end, connect the two hot's and ground to the outlet in their respective places on the 20A plug.

For those interested in what i'm wiring, it's a window A/C unit that rated as follows...20A 240VAC 60Hz 4800W. And the plug for it is a standard 20A that looks like a 15A -lug with one of the hot's horizontal.


Any and all help is needed. And I may not be an "Electrical" Engineer but I am a Computer Systems and Networking Engineer, so I'm not completely helpless...hahahahahaha!!!
 
Sponsored Links
  #2  
Old 07-20-16, 04:52 PM
ray2047's Avatar
Group Moderator
Join Date: Mar 2006
Location: USA
Posts: 33,597
Likes Received: 13
So this is a 3-conductor cable? If so use black, red, and bare and cap the white at the receptacle. You can also cap it at the panel if you want to.
 
  #3  
Old 07-20-16, 05:27 PM
Member
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 18,416
Likes Received: 5
A matter of terminology. The term service has a distinct definition in the National Electrical Code (NEC) and it pertains ONLY to the wiring from the point of the utility's connection to the first overcurrent device (fuse or circuit breaker) including the utility's watt-hour meter. In your case what you are dealing with is properly called a branch circuit.
 
  #4  
Old 07-20-16, 07:56 PM
Member
Thread Starter
Join Date: Jul 2016
Location: North America
Posts: 4
Ray, ur awesome bud!!! Seems like you have ur hand in most everything here.

So, it looks like everything went together ok except for the wiring in the walls are way too think to get all the strands into the new 20A/240V wall outlet. The wires were originally for the 40A service outlet that was already there for the range (if my range weren't gas, lol). If you can tell me the best way to connect these wires to this 20A outlet, I would be grateful.
 
Attached Images   
  #5  
Old 07-20-16, 08:04 PM
Member
Thread Starter
Join Date: Jul 2016
Location: North America
Posts: 4
Im just really hate the way it all looks. Most Marines have difficulty accepting shady looking sh*t.
 
  #6  
Old 07-20-16, 08:19 PM
Member
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 18,416
Likes Received: 5
Go to the store and buy three red wire nuts along with a foot each of #12 red and black insulated wire. Connect the #12 to the existing #8 wires with the wire nuts and then the #12 to the receptacle. Use the third wire nut to cap off the now redundant white wire after cutting the copper end flush with the insulation.

You won't need the entire foot of wire but it will be the minimal amount they will cut.
 
  #7  
Old 07-20-16, 08:43 PM
ray2047's Avatar
Group Moderator
Join Date: Mar 2006
Location: USA
Posts: 33,597
Likes Received: 13
You can also by wire nuts with attached pigtails.

Name:  term-a-nut_pigtail_zps8ea7bdfe.jpg
Views: 435
Size:  14.9 KB
 
  #8  
Old 07-20-16, 08:47 PM
Member
Thread Starter
Join Date: Jul 2016
Location: North America
Posts: 4
Thx so much...thats exactly what i'm doing tomorrow, after the store. I was trying to put something together not similar, and would have prob taken more time ������

ray, ty much bud...but do they make guage i would need for this application??

-Semper Fi
 
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