Electrical Upgrade

[ANG0225]

My 2012  Coachmen Chaparral periodically trips the 30AMP breaker on the park service.  We've had it for 2 years and it trips  primarily in the summer.  I am a Master Electrician but my experience with RV Electrical is limited.  I certainly don't want to fry anything.

Here is my proposed upgrade

• Run a 50 amp cord from the RV Parks pole to a new breaker panel that I will hang under RV.  This panel will be easily removable so that when we hit the road again we can pull it out easily.
• Attached to that panel will be a 30Amp receptacle that the existing RV cable will plug in to.  It will be fed from a 30 amp single pole breaker in the panel.
• From that Panel I will run a 12/2 with ground up to my existing panel inside my RV.  I will then disconnect the AC circuit from it's circuit breaker inside the RV and splice it to the new 12/2 with ground that I installed.

Here is my thinking.  My breaker is tripping on the park service because something else is on with it, or the breaker is weak.  I have actually put an ammeter on the service with my AC is on and it is around 25-26amps.

The 50 amps from Park Service will then be split up between the AC and the rest of my coach.

 

Any critiques or warnings?

 

[oldjohnt]

WARNING those who don't like long deep discussions and theory you don't have to read this !

Wow a Master Electrician, I certainly respect that profession and much of my professional career (Power Distribution Design Engineer) I spent working with such and electrical technicians, we got along great and worked well together. I learned a thing or two from them along the way and likewise, they from me.

Okay you ALREADY know all this, but for the benefit of some who may not, the thing different about an RV is that unlike the main panel in a home, in the RV panel the Neutral Buss and Equipment Ground Busses are separate and electrically insulated and isolated from each other. The tub/frame, of course, is bonded to the Equipment Ground but NOT the Neutral. The RV panel is treated like a "sub panel" (which it is) fed off a main panel and complies with single point grounding theory and there be ONLY ONE Neutral/Ground BOND.  

Your proposal to use the 50 amp two leg park power so you can run the rest of the RV off one leg and your AC off the other leg sounds fine to me in theory at least, provided all overcurrent protection and grounding is proper which you are well qualified to undertake.

LET ME WALK MYSELF THROUGH THIS to see if were on the same page ?? Your new 120/240 volt single phase three wire 50 amp panel is fed by 6/3 w/ground rubber cord, it has separate Neutral and Ground Busses, and it has a 30 amp 120 volt single pole breaker (leg A) to feed your 30 amp 120 volt RV receptacle into which your existing power cord will be plugged. Is it correct that NEW panel ALSO has a 120 volt 20 amp single pole breaker FED OFF THE OTHER LEG FROM WHICH THE RV RECEPTACLE IS SERVED which you're going to use to power your AC ??????????  

So far that above still sounds okay to me HOWEVER that splicing of your AC circuit in the existing RV panel seems different although, sure, it will "work"  but I need to "sleep on it and ponder"  There are other ways to accomplish what you intend but I wonder about the use of or removal of the new panel you spoke of above ??? Maybe some sort of dual receptacles or a transfer switch so you can switch the AC feed from one source or another ??  It's more the mechanics, logistics and any switching of this I'm not sure of for now, but the idea of RV on one leg and AC the other sounds fine.

As you know its the Thermal portion of a 30 amp Thermal Magnetic Circuit Breaker that is heating up and tripping due to a long sustained 25 amp draw or a weak breaker as you mentioned 

Some folks use a 50 to 30 amp dogbone adapter to feed their 30 amp RV via the 50 amp service ya know (not an answer to your problem exactly but can help some situations), but absent correct and proper overcurrent protection its NOT something I'd recommend !!!  

Enough for now, theory sounds fine but not sure of the wiring and connections and methods and "removal" you spoke of?? 

 

John T

[Dutch_12078]

Our previous motorhome was 30 amp and had two air conditioners. On shore power, there was a selector switch that let us choose which A/C was in use, but on generator power, we could run both at the same time. To get around the single A/C shorepower limit, I isolated the line to one of the A/C's and inserted a 20 amp standard plug/socket set in the line, with the socket on the hot side. When plugged into shore power, I could then break the connection and plug the A/C into a 20 amp rated extension cord that was in turn plugged into the 15/20 amp outlet at the shorepower stanchion. That setup worked quite well for us, even on sites that only had 30 amp and 15/20 amp outlets. In those rare situations where only 50 amp and 30 amp outlets were available, I used a 50/30 adapter for the 30 amp cord, and a 30/20 adapter for the 2nd A/C. In the 6 years we owned that coach, we never blew a 30 amp breaker on a park stanchion, but we also knew what appliances we could and could not use at the same time.

[Chad Heiser]

What you propose to do is electrically ok, as long as you heed old john's warning about keeping the neutral and ground bus bars separate.  

Dutch's solution is essentially doing the same thing you are talking about with fewer modifications to your rig and less out of pocket expense.

If I were in your situation and had your background, I would probably just rewire the whole coach to a 50 amp coach.  The parts to do this would essentially be the same as you would need to do your described fix and it would not have to be removed when you are ready to move.

[oldjohnt]

Yo Good Dutch Man,

 When you say " even on sites that only had 30 amp and 15/20 amp outlets. In those rare situations where only 50 amp and 30 amp outlets were available, I used a 50/30 adapter for the 30 amp cord, and a 30/20 adapter for the 2nd A/C."

 Not being there I cant say, but WONDER if a pedestal has ONLY a 30 amp receptacle and 15/20 amp receptacle if there happens to be BOTH legs available (depends on how many wires they ran  DUH) in there with each receptacle on their own leg orrrrrrrrrrrrr if they only ran one 120 leg to the pedestal, depends on the park and its age Id guess   ??? Of course if it has all three, a 50 amp and a 30 amp and a 15/20 amp receptacles, hopefully the 30 and 15/20 are on separate legs. FWIW That's how I would design it.

 Your method sounds cheap easy and simple, a country boy can survive !!! I have some small "heartburn" with a 50 Amp Male to a 30 amp Female dogbone to plug in the RV's 30 amp power cord BUT FOR DARN SURE IT WORKS and I see it done all over.

Fun sparky chattin with yall. Now the OP a Master Electrician can do as he well pleases, he's certainly qualified. 

John T  

 

 

[Pat & Pete]

I'd agree with John T .

[Bob A]

Why not upgrade rv panel and power cord to a 50 amp and split loads at the new panel 

[Kirk W]

10 hours ago, ANG0225 said:

My 2012  Coachmen Chaparral periodically trips the 30AMP breaker on the park service. ......................... .

I have actually put an ammeter on the service with my AC is on and it is around 25-26amps.

 

I think that I would first try using a 50a/30a adapter to connect to the parks 50a outlet if there is one in the box that you now use. If your RV is wired like all of the ones that I have owned, the RV power cord enters your distribution box through a master 30a breaker which would open if you exceed 30a and still protect your RV even if you are plugged into a 50a outlet. There is a possibility that you would still trip the 30a breaker, just now the one inside of your RV, but it is so easy that I would at least try that first. 

[Dutch_12078]

3 hours ago, oldjohnt said:

Yo Good Dutch Man,

 When you say " even on sites that only had 30 amp and 15/20 amp outlets. In those rare situations where only 50 amp and 30 amp outlets were available, I used a 50/30 adapter for the 30 amp cord, and a 30/20 adapter for the 2nd A/C."

 Not being there I cant say, but WONDER if a pedestal has ONLY a 30 amp receptacle and 15/20 amp receptacle if there happens to be BOTH legs available (depends on how many wires they ran  DUH) in there with each receptacle on their own leg orrrrrrrrrrrrr if they only ran one 120 leg to the pedestal, depends on the park and its age Id guess   ??? Of course if it has all three, a 50 amp and a 30 amp and a 15/20 amp receptacles, hopefully the 30 and 15/20 are on separate legs. FWIW That's how I would design it.

 Your method sounds cheap easy and simple, a country boy can survive !!! I have some small "heartburn" with a 50 Amp Male to a 30 amp Female dogbone to plug in the RV's 30 amp power cord BUT FOR DARN SURE IT WORKS and I see it done all over.

Fun sparky chattin with yall. Now the OP a Master Electrician can do as he well pleases, he's certainly qualified. 

John T  

 

 

John, while it's certainly likely the 30 and 20 amp outlets are on a single leg feed, as long as the feed is large enough to support the total current load and the outlets are individually breakered, there's no problem with that set up. And it is code compliant...

[ANG0225]

18 hours ago, oldjohnt said:

WARNING those who don't like long deep discussions and theory you don't have to read this !

Wow a Master Electrician, I certainly respect that profession and much of my professional career (Power Distribution Design Engineer) I spent working with such and electrical technicians, we got along great and worked well together. I learned a thing or two from them along the way and likewise, they from me.

Okay you ALREADY know all this, but for the benefit of some who may not, the thing different about an RV is that unlike the main panel in a home, in the RV panel the Neutral Buss and Equipment Ground Busses are separate and electrically insulated and isolated from each other. The tub/frame, of course, is bonded to the Equipment Ground but NOT the Neutral. The RV panel is treated like a "sub panel" (which it is) fed off a main panel and complies with single point grounding theory and there be ONLY ONE Neutral/Ground BOND.  

Your proposal to use the 50 amp two leg park power so you can run the rest of the RV off one leg and your AC off the other leg sounds fine to me in theory at least, provided all overcurrent protection and grounding is proper which you are well qualified to undertake.

LET ME WALK MYSELF THROUGH THIS to see if were on the same page ?? Your new 120/240 volt single phase three wire 50 amp panel is fed by 6/3 w/ground rubber cord, it has separate Neutral and Ground Busses, and it has a 30 amp 120 volt single pole breaker (leg A) to feed your 30 amp 120 volt RV receptacle into which your existing power cord will be plugged. Is it correct that NEW panel ALSO has a 120 volt 20 amp single pole breaker FED OFF THE OTHER LEG FROM WHICH THE RV RECEPTACLE IS SERVED which you're going to use to power your AC ??????????  

So far that above still sounds okay to me HOWEVER that splicing of your AC circuit in the existing RV panel seems different although, sure, it will "work"  but I need to "sleep on it and ponder"  There are other ways to accomplish what you intend but I wonder about the use of or removal of the new panel you spoke of above ??? Maybe some sort of dual receptacles or a transfer switch so you can switch the AC feed from one source or another ??  It's more the mechanics, logistics and any switching of this I'm not sure of for now, but the idea of RV on one leg and AC the other sounds fine.

As you know its the Thermal portion of a 30 amp Thermal Magnetic Circuit Breaker that is heating up and tripping due to a long sustained 25 amp draw or a weak breaker as you mentioned 

Some folks use a 50 to 30 amp dogbone adapter to feed their 30 amp RV via the 50 amp service ya know (not an answer to your problem exactly but can help some situations), but absent correct and proper overcurrent protection its NOT something I'd recommend !!!  

Enough for now, theory sounds fine but not sure of the wiring and connections and methods and "removal" you spoke of?? 

 

John T

Very thoughtful advice.  Thanks!

[oldjohnt]

Dutch, Thanks for the feedback

Looks like we agree and are on the same page. If the pedestal ONLY has 30 Amp and 15/20 Amp receptacles they "probably" only ran a single (one leg) Hot, Neutral and Ground to the pedestals. Indeed, sufficient ampacity feeders and proper overcurrent protection and perhaps even the "tap rules" may come into play making it all code compliant. Obviously in years past long before the behemoth 50 amp RV's, 30 amp and single leg distribution was adequate. 

 

ANG,

You're welcome.  

John T  Long retired and rusty on this but still enjoy the topic and try to help if I can

 

[ANG0225]

Thank you all for the well thought out responses!