Replace old Onan 5000 with box store portable

[colonelcorto]

I have a 1996 Fleetwood Southwind with a non-functioning Onan 5000. It has a fuses B winding, and a burnt up voltage regulator. I know this because, luckily, Inlive with 5 miles of an Cummins/Onan dealer/service center. For $120 they were able to tell me that the cost to repair is estimated at $1,800. I can afford to burn up a cheap off-brand portable every couple of years for that price. Let me be clear, I am not interested in spending the $1,800 to repair a 23 year old generator. A newer Onan 5500 is $4,000 installed; also out of the question.

My unit has 30 amp service and two roof mount AC units. I believe one is a 12.5k btu and the other is a 15k btu unit. The dead Onan was a single phase 120 volt system that was rated for 41.5 amps. There are two separate input lines running to the transfer switch: a 20 amp and a 30 amp line. I know this because the circuit breakers on the side of the dead Onan were labeled as such. I am almost certain the 30 amp ran the entire motorhome except the rear AC unit (12.5k) which is ran by the remaining 20 amp circuit.

I am aware that My motorhome cannot use the 30 amp 240 volt plug that is in most portable generators, it’s 120volts only. However, can I spit 240 volts into 2x 12 volts and energize those two input lines that run to the transfer switch? Each line would see 120 volts, right? There would be no danger of 240 showing up anywhere, right?

I would like to be able to use my motorhome in the hot summer months and do the occasional boondocking. This requires a functional generator. I would also like to not set myself or my family on fire.

Thanks!

[Passin_Thru]

Why do you ask when you've already made up your mind?

[crawford]

My friend has a winnie has 2 air units and some kind of control unit which controls the ac so not to come on at the same time. It's the damest thing I ever seen on a 30 amp system wondering if this is the same thing?

[hipower]

It seems defeatist to do what the OP is thinking when the result is far less convenient than the original generator installation. Remote start, on board fuel supply, use of all existing wiring, etc is worth much more than saving a few hundred dollars by adapting something that may be acceptable, or not.

I might check some of the RV salvage places for a replacement ONAN if the repair cost is prohibitive. Possibly find one for about equal cost as the contractor models.

[wa8yxm]

IF you want a "Road" generator.. YOu might re-locate your power inlet to the REAR of the RV and put a cargo tray on a dual hitch adapter..

A "rise/drop" type hitch adapter doubles as the Drop (most likely) hitch adapter for your towed car and a 2nd 2" receiver ABOVE that. Make sure it is high enough and you mount a Cargo Tray (Harbor Freight, CW, Most Bigger RV places) and attach the portable generator there, Fully open air, and make sure exhaust points to the rear (Away from RV) then simply plug in

Do use locks to secure.

DO NOT run in a campground Even if power is lost (i've had to use my ONAN on site a few times due to lack of "Shore" power.. Little storm (Hurricane Matthew) for example, was one such case.

[10forty2]

colonelcorto wrote:
........ The majority of the use would be while driving so I could run the roofmount.

If htat's really your main goal, then I doubt that a portable unit is going to fit the bill for you, for all the reason stated previously about heat dissipation, fuel supply, exhaust routing, etc.

Just a thought.....poke around on Craigslist and see if anyone might be parting out a junker and have a good on-board genset you could pick up for a song....

[DrewE]

MrWizard wrote:

I have heard my onan run, it's quiet. I've also had a portable, it's loud - I get it. The majority of the use would be while driving so I could run the roof mount

A/C ?

then the portable genny in the OEM compartment is a bad idea
for all the reasons i mentioned in my previous post

I entirely agree with Mr Wizard in this. Electrically, what you suggest is entirely workable, which was your initial question; but running a portable generator in the built-in compartment would be a big safety and logistical challenge, at the very least. Contractor generators are designed to run in the open air, and don't have provisions for routing exhaust, cooling air, etc. out of an enclosure, nor for pumping and using fuel from a remote tank.

It might be possible to mount and use the generator on a hitch-mount cargo rack extending from the back of the motorhome if you ran appropriate wiring to that area and don't need the hitch for other (i.e. towing) uses. I would not recommend it still, but it would be less unsafe in my opinion than trying to jury-rig a setup to use it in place where the built-in generator sits.

[MrWizard]

I have heard my onan run, it's quiet. I've also had a portable, it's loud - I get it. The majority of the use would be while driving so I could run the roof mount

A/C ?

then the portable genny in the OEM compartment is a bad idea
for all the reasons i mentioned in my previous post

[hilldude]

My 4000 watt quit, bit the bullet and had it repaired.$1600.

[colonelcorto]

wa8yxm wrote:
You mentioned a "Box Store Portable" and from other things I am fairly sure you are talking about "Contractor Grade" generators.

Do me and everyone else a favor

Listen to another RVer's Onan as it powers his RV

Then LIsten to a Contractor's generator under half load.. (Ear plugs may be recommended).

Then consider your poor neighbors.

NOTE a pair of Honda Eu-2000i's or even a pair of 3000I's (that will run most 50 amp rigs no problem) No ear plugs needed.

I have heard my onan run, it's quiet. I've also had a portable, it's loud - I get it. The majority of the use would be while driving so I could run the roofmount.

[wa8yxm]

You mentioned a "Box Store Portable" and from other things I am fairly sure you are talking about "Contractor Grade" generators.

Do me and everyone else a favor

Listen to another RVer's Onan as it powers his RV

Then LIsten to a Contractor's generator under half load.. (Ear plugs may be recommended).

Then consider your poor neighbors.

NOTE a pair of Honda Eu-2000i's or even a pair of 3000I's (that will run most 50 amp rigs no problem) No ear plugs needed.

[wildmanbaker]

I believe there is a point that is being missed here. The 240 volts is two legs of 120 volts, but each is 180 degrees out of phase with each other, and a common ground. To get this to work, you would need a 50 amp service in the MH which has to separate supply bars in it. Without this, you would be looking at most of the electronics being cooked inside the MH.

[Mile_High]

I would have to have my air while traveling. Portable type generator would not be an option for me.

[colonelcorto]

Teacher's Pet wrote:
I see you are in Elkhart. Why not visit one of the "Amish" power plant sales and service companies in the Shipshewana area. They may be able to fix it for way less than Onan Indiana/Coach Care or might remove/buy it from you for parts if the repair is beyond your budget.

This is a really good idea. Going to try it.

[Teacher_s_Pet]

I see you are in Elkhart. Why not visit one of the "Amish" power plant sales and service companies in the Shipshewana area. They may be able to fix it for way less than Onan Indiana/Coach Care or might remove/buy it from you for parts if the repair is beyond your budget.