Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Electrical

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread Display Modes
Old 01-20-2011, 06:26 AM   #1
Newbie
 
Join Date: Jun 2008
Posts: 26
Rewards Points: 25
Default

50 amp RV service


I have to move my RV plug out another 100'. It currently runs underground 100' from the main panel using 4 - #6 THHN wires in plastic.

My question is can I add another 100' to this run? If so should I now use #4 or will #6 be good? Or will I have to start all over from the main in order to run the entire 200'?

Thanks

hd82 is offline   Reply With Quote
Old 01-20-2011, 08:55 AM   #2
Member
 
Join Date: Nov 2007
Location: Nashua, NH, USA
Posts: 6,964
Rewards Points: 2,024
Default

50 amp RV service


I don't have the calculations but I say it is safe to do this.

Figure out the wire size for redoing the entire run.

Use an equal amount bigger than that for the new extension, keeping the existing section as-is. For example if you would need one size larger (here, #4) wire for the entire run, leave the #6 wire in place and use one more size larger (here, #2) wire for the extension.

(For those eavesdropping, if the extension were longer, yet a larger size would be needed to have negligible added voltage drop while keeping the existing wires in use.)

__________________
Forget super sized fries. The Washington Redskins could promote healthy eating with First Lady Obama by choosing a (red skinned) turnip for a mascot.

Last edited by AllanJ; 01-20-2011 at 09:12 AM.
AllanJ is online now   Reply With Quote
Old 01-20-2011, 09:24 AM   #3
Electrical Supplier
 
Join Date: Jun 2010
Location: Dayton, OH
Posts: 205
Rewards Points: 150
Default

50 amp RV service


By my calculations he should be able to extend his wire to 200 feet with 6/6/6/6 copper and only be at 4.1% Voltage Drop at full amp load. (you want no more than 5%)

I say extend it with 6/6/6/6 Copper THHN to your new location.

Using #2 would be wasteful and unnecessary for this job.
__________________
"Do it right the first time and avoid duplication of effort"

Your AHJ/Inspectors ALWAYS have the final say on ANY electrical code issue.
If in doubt, contact a licensed, experienced, reputable electrician to perform the work.
LyonsElecSupply is offline   Reply With Quote
Old 01-20-2011, 10:10 AM   #4
Electrician
 
Join Date: Nov 2005
Location: Winnipeg, Manitoba
Posts: 1,147
Rewards Points: 510
Default

50 amp RV service


Is it 3% or 5% in a branch circuit. I know in Canada we are allowed only a 3% drop in a branch circuit and I thought the US was the same.
darren is offline   Reply With Quote
Old 01-21-2011, 03:35 AM   #5
Newbie
 
Join Date: Jun 2008
Posts: 26
Rewards Points: 25
Default

50 amp RV service


From the info I get on different wire size calculators to run a new line I would need 200' of #4.
http://www.csgnetwork.com/voltagedropcalc.html

http://www.csgnetwork.com/wiresizecalc.html

If I understand the replys here I should use #4 to extend from the original. Or I can run a new 200' with #4.

The price of #4 varies from $1.02 at Lowes to $0.80 at NOTOCO here in New Orleans. If I go with a new 200' run can I use 4-4-6-8 then add a ground rod at the end? #6 neutral is $0.55 and #8 ground is $0.33, I already have the 1/2" ground rod.

Thanks

Last edited by hd82; 01-21-2011 at 03:39 AM. Reason: added links
hd82 is offline   Reply With Quote
Old 01-21-2011, 05:09 AM   #6
Member
 
Join Date: Mar 2007
Location: Eighty Four, Pa.15330
Posts: 1,281
Rewards Points: 560
Default

50 amp RV service


Are you drawing even 30 amps continually? Then extend # 6 Thwns.
bobelectric is online now   Reply With Quote
Old 01-21-2011, 06:15 AM   #7
Newbie
 
Join Date: Jun 2008
Posts: 26
Rewards Points: 25
Default

50 amp RV service


I don't know what the draw is or will be, this is my first RV and I just bought it 3 wks ago. It has a 50amp plug so I ran a 50 amp service.

It has two A/C units and a full size refrig, ceiling fan, convection microwave, electric water heater. I don't have a clue as to how many amps it will pull in the summer time. This is why I want to be sure I get it right, so I ask the gurus of electric to give me advice.

Thanks
hd82 is offline   Reply With Quote
Old 01-21-2011, 06:18 AM   #8
Member
 
Join Date: Mar 2007
Location: Eighty Four, Pa.15330
Posts: 1,281
Rewards Points: 560
Default

50 amp RV service


You'll be fine.
bobelectric is online now   Reply With Quote
Old 01-21-2011, 07:41 AM   #9
Member
 
Join Date: Nov 2007
Location: Nashua, NH, USA
Posts: 6,964
Rewards Points: 2,024
Default

50 amp RV service


Just redid my calculations and, if you can take a 4% voltage drop at the full 50 amps (voltage drop will be under 3% at 40 amps) then you can go with 6 gauge copper all the way. (using 0.4 ohms per 1000' for 6 gauge)

For under 3% voltage drop at 50 amps you can run #4 for the extension leaving the existing #6 in place back to the house. You would not need to upgrade the latter unless you need more than 50 amps at a later date.

The number of volts dropped in any segment of wire equals the amperes flowing times the resistance of that segment and does not depend on the supply voltage. However you must also follow the wire size/type versus amperes rules for example no more than 30 amps for #10 copper Romex cables.

__________________
Forget super sized fries. The Washington Redskins could promote healthy eating with First Lady Obama by choosing a (red skinned) turnip for a mascot.

Last edited by AllanJ; 01-21-2011 at 07:55 AM.
AllanJ is online now   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Lennox service valve questions leeh1212 HVAC 12 07-26-2013 08:59 AM
Wiring Size Calculations for New Service CorinthWest Electrical 7 12-07-2010 11:36 AM
Service mast options bsperr Electrical 6 12-09-2009 08:48 AM
Remodel - Moving from 200 amp service to 320 amps stevedar Electrical 20 11-29-2009 08:14 PM
Grounding for two service entrances to same house. jogr Electrical 18 09-24-2008 10:31 AM




Top of Page | View New Posts

Copyright © 2003-2014 Escalate Media. All Rights Reserved.