Converting 30 amp system to 50 amp

[wow]

What is involved in converting a 30 amp motorhome to a 50 amp? Can it be done? Re-wire?

Thanks

WOW

 

[Water Dog]

A minimum of changing out the breaker panel to a 50 amp panel, the service cord, and tarnsfer switches. Any circuits that would be split would require additional wiring.

 

[Icemaker]

A minimum of changing out the breaker panel to a 50 amp panel, the service cord, and tarnsfer switches. Any circuits that would be split would require additional wiring.

Would you be able to keep existing inverter/charger and the same generator??

George

 

[Ned]

The inverter and charger would be fine, but the generator may be a consideration.  It's certainly a single phase model and while it could be used to power both legs of a 50A load center, it would be better to upgrade it to a model with 2 outputs.  Depending on the generator location, that may not be an easy job.

 

[Just Lou]

The inverter and charger would be fine, but the generator may be a consideration.  It's certainly a single phase model and while it could be used to power both legs of a 50A load center, it would be better to upgrade it to a model with 2 outputs.  Depending on the generator location, that may not be an easy job.

Onan 5K (actually 5.5K) generators installed in most 30amp coaches in the last 10/15 years already have two outputs.  One 30amp and one 20amp that could be utilized in a conversion from 30 to 50 amp service.

 

[Ned]

If that's what he has that would work.  Even our 50A coach has a generator that supplies only 30A per leg from the generator.

 

[Wizard46]

WOW, What unit do you have.

I converted mine, only had to but breakers and wire, not that difficult a job. Would be glad to share experience with you if it would be applicable to your unit.

My generator has 30/20 amp output, works good for me but can't run everything at the same time like a true 50amp service.

 

[wow]

Thanks for the replies.

Mine is an Onan Marquis 5000 with a 30 and a 20 amp breaker. It is rated at 41.7 amps. My service cord is a 10/3 all the way. Any help, Wizard, would be appreciated. There are occasions when I would like to run both A/C units at one time. That is all I am concerned about.

Thanks, again,
Will Walker

 

[Wizard46]

My Winnebago had 50 amp as an option that was not installed. See this link http://www.rvforum.net/SMF_forum/index.php?topic=39870.msg370337#msg370337

Winnebago has all necessary wiring diagrams online.

 

[Ron from Big D]

You could run both a/c units as long as each is wired on a separate leg of the 50 amp service.

 

[Lou Schneider]

There are occasions when I would like to run both A/C units at one time. That is all I am concerned about.

Then the easiest solution is to bring the second A/C out on it's own 20 amp cord, not rewire the coach.

You could bring the second A/C to a 20 amp plug in a utility bay, with a dedicated outlet to plug into so it draws power from the rig's distribution system like it does now.  When you want to run both air conditoners from shore power, you unplug the second A/C from the rig socket and power it from a 20 amp extension cord running to the 20 amp outlet in the park pedestal.

 

[John From Detroit]

If it is a trailer with no generator you need only change the power cord (including the internal cord from the inlet, if any, to the breaker box)  and the breaker box (Which often is also the fuse box and the power converter).

If it has a generator you also need change the Transfer Switch, and as above all the wires from inlet to breaker box.

Now, if all you want is the ability to run TWO Air conditioners at once try this.

"Break out" (Technical term) the rear AC,, By that I mean pull the power lead for it out of the breaker box and using a proper junction box and extension wires, Extend it to the outside of the rig, either a basement compartment or a "Access hatch" (I put in an access hatch)  Optionally (And I do recommend this) you can run a cord from the original breaker to the same hatch or compartment, I used a 12ga extension cord, cut in in half, Used both halves (The outlet end connects to the breaker)

There is a company (or you can make your own) that sells a 50 amp plug that "Splits" to two 30 amp outlets

Get the adapter that lets you plug in a 15/20 amp cord to a 30 amp outlet.

Get a 12ga extension cord (Sears, K-mart, have ones with a lock-on outlet end, I like those)

Plug your RV, save for the one A/C into one of the 30 amp "legs" and the remaining A/C using the 12ga cord, to the other.

NOTE> with this configuration you should put a 20 amp breaker in that junction box where the cord meets the original A/C power line.

Major advantage.. When parked on a 30 amp site,, Plug the 2nd A/C into the 20 amp outlet using the aforementeioned cord.

 

[wow]

Thanks, Lou and John,
I understand about bringing one A/C unit to a bay I will do that. I know that will work for shore power, but what about with generator power? Should I change the 20 amp reaker to a 30 amp? Will the 5000 Onan carry both units?

Thanks, again,

Will Walker

 

[Just Lou]

Thanks, Lou and John,
I understand about bringing one A/C unit to a bay I will do that. I know that will work for shore power, but what about with generator power? Should I change the 20 amp reaker to a 30 amp? Will the 5000 Onan carry both units?

Thanks, again,

Will Walker

Search the Onan 5K generator model number that you have.  Chances are, you will see a note that the generator is really a 5.5K with enough power to run both ac's.  Mine does, and it's a 1997 unit in a 30amp coach.

My two air units are controlled by an Intellitec ECC (Electronic Climate Control) system that includes a dual control, dual thermostat, wall mounted control.  The ECC can be viewed and explained here.  This system attempts to run both ac units on 30aqmps via a load shedding technique.

The two diagrams attached explain how I modified the coach wiring to be able to selectively run the second air conditioner from an extension cord to a separate 20amp service when on shore power.

 

[Just Lou]

Then the easiest solution is to bring the second A/C out on it's own 20 amp cord, not rewire the coach.

You could bring the second A/C to a 20 amp plug in a utility bay, with a dedicated outlet to plug into so it draws power from the rig's distribution system like it does now.  When you want to run both air conditoners from shore power, you unplug the second A/C from the rig socket and power it from a 20 amp extension cord running to the 20 amp outlet in the park pedestal.

Lou, this is all  exactly the only thing that I wanted to do with the process described in my previous reply.

I haven't had occasion to try it lately, but during my initial testing, I seemed to have some conflict between the ECC thermostat controls and the ac unit being operated from the extension cord.  Have you, or anyone else following this topic, experienced this?  Could there be some validity in (after separation of 120ac sources) that a conflict exists between the 120 source driving motors and compressors and the 120ac source fed to the controls?  Should this matter?

I'll get a chance to check it later in July.  Right now, I have no separate 20amp source.

 

[Jammer]

Lou

Some EMS check for the presence of 50a service by looking for voltage between the two hot legs.  With a "break out" configuration that won't exist and so the EMS will impose whatever limits it usually does with 30a service, possibly including a limit of one air conditioner running at once.

If no other loads are present it may be possible to run both air conditioners at once with 30A service.  It depends on the size of each air conditioner and the supply voltage, since they will draw more current at lower voltages.  If I have good power at 120V or more the air conditioners draw 26 amps combined on high fan, a little less on low fan.

 

[Gary RV_Wizard]

You can do with a 50A shore cord what is probably now done with your generator - one 30A "leg" to run the main house circuits plus a second 20A "leg' to power the rear a/c. The second hot leg of the 50A shore cord in effect becomes the "extension cord" suggested above. However, if you stick with a separate 20A extension cord rather than integrating it into a 50A shore cord, you retain the flexibility to use it on a 30A site that may have a secondary 20A outlet avail;able with an independent power source. Note that most 30A RV sites piggy back the 20A outlet onto the 30A, so that you only have a combined 30A total anyway.

 

[John From Detroit]

An Onan 5000 should take both A/C's no problem, a 5500 here runs both A/Cs the water heater, fridge, and microwave all at the same time, (And an entire Field Day multi-operator radio set up as well)

Each Air Conditioner needs to have it's very own circuit breaker, and if you go 50 amp one is on L-1 and the other on L-2 (The two legs)  Thus no need to change the breaker,  Just add one.

If you do the Rear AC like I did (Run the outlet end of an extension cord out so I can plug it in to the normal system) Then on generator.. IT works as designed.

IF you do not upgrade to 50 amp,  But just add the 2nd line, Then the genrator has a 20 amp breaker (usually) and a 30,  Feed the 20 to an outlet near the plug.

 

[Just Lou]

Lou

Some EMS check for the presence of 50a service by looking for voltage between the two hot legs.  With a "break out" configuration that won't exist and so the EMS will impose whatever limits it usually does with 30a service, possibly including a limit of one air conditioner running at once.

If no other loads are present it may be possible to run both air conditioners at once with 30A service.  It depends on the size of each air conditioner and the supply voltage, since they will draw more current at lower voltages.  If I have good power at 120V or more the air conditioners draw 26 amps combined on high fan, a little less on low fan.

None of what you describe has any relevance to my coach as it is (as previously stated) a 30amp coach.  It does NOT have an EMS, it does have an ECC unit that does the same thing ONLY where the ac-units are concerned.

 

[Just Lou]

JFD and Gary B., I'm not sure if you were responding to my post or the original, so I'll apologize  for thread theft and leave this topic to develop in response to the OP.