Upgrading electrical panel to 50 amp.

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Jim Shuff

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Sep 2, 2018
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    I am upgrading my 5th wheel to 50 amp before we had south in January.  I have purchased a 50 amp panel with more circuits available for both 110 V and 12 v dc and plan to rewire a lot of the circuits to isolate them.  I have the new 50 amp outside connector for the power cord to attach to the trailer.  What I need to know is the size of the wire that I need to run from the outside connection to the new panel.  One question that I have is the electrical post at the campgrounds labeled 50 amp are these made up of two 25 amp circuits or is each side 50 amp.  If they are 25 amp each side, I can use 10/3 with ground from the connection to the panel.  If, they are an actually 50 amp both sides that 8 gauge entrance type cable is needed.  Can someone clue me in on this?  We are upgrading our 2000 unit for both clothes washer and dryer.  Last winter, without these, the post breaker, 30 amp, would kick off with the A/C going and using just about anything else 110.  Thank you.
 

HueyPilotVN

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Maybe this will help.

Skip the Photobucket pictures, the pictures are posted in reduced size in the second post.

http://www.rvforum.net/SMF_forum/index.php/topic,66762.msg947194.html#msg947194
 

grashley

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May 7, 2015
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Western Kentucky
The 50A is actually 50Amp @ 240 Volts.  When the power comes inside, the main breaker splits this into two 50A 120V feeds.  Typically, the main breaker is in the middle of the split buss, and circuits to the left  feed from the left 120V feed, and those to the right...

8 Ga is what you need - nothing smaller!

This is also a great time to add a hard wired EMS like the Progressive HW50C.  It protects your hard work and the camper from low voltage, high voltage, spikes, and more.  Really cheap insurance for poor quality camp shore power.
 

Gary RV_Wizard

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A standard 50A shore power cord is 6 gauge, not 8 gauge.  8 gauge is sufficient for certain types of wire (e.g.THHN) but not for the more common NM or UF wiring (which are rated at 40A for 38).  If in any doubt about the actual ampacity rating of the wire type you are using, go with 6 instead of 8. Those rating are for an 86 F. ambient temperature too, and that's borderline for an RV's working environment.

You mentioned service entrance cable - those are often higher rated and have superior insulation and jacketing.  #8 might be ok.
 
S

sightseers

Guest
RV's are electrically strange.

I was taught that you are not supposed to use solid copper wire in a motor vehicle.

But every branch circuit in my whole rig is wired with 3 wire #14 Romex.  ???
 

John From Detroit

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Davison Michigan
I too believe in over-sized wires.. if 8ga will do than 6ga will do better.  for the distance you are running cost is not much different so go for the bigger wire. 
 

xrated

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"Murvil", E. TN.
Jim Shuff said:
    I am upgrading my 5th wheel to 50 amp before we had south in January.  I have purchased a 50 amp panel with more circuits available for both 110 V and 12 v dc and plan to rewire a lot of the circuits to isolate them.  I have the new 50 amp outside connector for the power cord to attach to the trailer.  What I need to know is the size of the wire that I need to run from the outside connection to the new panel.  One question that I have is the electrical post at the campgrounds labeled 50 amp are these made up of two 25 amp circuits or is each side 50 amp.  If they are 25 amp each side, I can use 10/3 with ground from the connection to the panel.  If, they are an actually 50 amp both sides that 8 gauge entrance type cable is needed.  Can someone clue me in on this?  We are upgrading our 2000 unit for both clothes washer and dryer.  Last winter, without these, the post breaker, 30 amp, would kick off with the A/C going and using just about anything else 110.  Thank you.

8 ga would suffice if you use conduit and THWN wire, but the NM-B (Romex) and UF will require 6 ga....as in 6/3cond with a ground.
 
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