Safely run long 220v *temporary* service

Reply

  #1  
Old 09-30-17, 07:08 PM
U
Member
Thread Starter
Join Date: May 2004
Location: USA
Posts: 145
Received 0 Votes on 0 Posts
Safely run long 220v *temporary* service

I'm in the midst of a project, and need power out at my barn. I have a 100' #10 extension cord running lights and a vacuum. I need to run a planer - 3HP motor, 220v.

Ideally, I would be able to do the following:

wire a permanent outdoor 220v 20A (or 30A) outlet
run an extension cord for the 220v machine

Now, can this be done safely? I looked at some charts (length / current / voltage) and if I'm consuming 20A, then a #12 would be sufficient. For 30A #10.

However, I have some concerns since the setup would be:

circuit breaker -> 10' wire -> outlet -> plug -> 105' cable -> socket (in metal box) -> plug -> 5' wire -> planer

Do all of these connections add resistance to the assembly? Is there a difference between solid and stranded #12 when it comes to current carrying capability?

I priced out wire - pretty expensive. I would like to be able to reuse whatever I purchase, and will only have it out for a week. I could move the planer up to the house, but it is very heavy and I would also have to move all of my wood.
 
Sponsored Links
  #2  
Old 09-30-17, 07:15 PM
U
Member
Thread Starter
Join Date: May 2004
Location: USA
Posts: 145
Received 0 Votes on 0 Posts
Would something like this work for the extension? I'd prefer to make my own, but #10 is $1.89/ft so this is priced better.

https://www.amazon.com/dp/B000GAQG7U/
 
  #3  
Old 09-30-17, 07:23 PM
I
Forum Topic Moderator
Join Date: Feb 2005
Location: Near Lansing, Michigan
Posts: 10,944
Received 43 Votes on 41 Posts
A 3HP motor at 240V draws about 9 amps, so you should be OK with a #12 or #10 cord. The problem with voltage drop will be worst when the machine first starts up and when the motor bogs down under load. Either of these could cause a stall and the breaker will trip. I'd suggest to not work the planer too hard -- take light passes. If it seems like the motor is overheating or the thermal breaker pops, you'll need a heavier cord.
 
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
 
Ask a Question
Question Title:
Description:
Your question will be posted in: