How do I install a Generator not designed for an RV?

[LVLFNXS]

Sent: 3/12/2004

I am looking at getting a 5kw Generac generator.  Is it a rough job installing it in my Coach?  What should I do to hook it up properly, both gas and electrically?  Thank you for your help in advance.

Erik

[denisondc]

Sent: 3/12/2004

Mine just has a rubber line feeding from the main tank via a Tee fitting where the pickup tube from that tank emerges: With a mechanical shut-off valve in the genset box, and an in-line fuel filter, which I should probably change. An important consideration is blowing the hot air and exhaust away from under the RV.
Before you install it I would give the inside of the genset space a check for structural integrity, then a good coat of rustoleum.
I have no idea about the electrical hookup.
Gonna Take pictures?

[LVLFNXS]

Sent: 3/12/2004 10:05 PM

Of course I am going to take pictures.  Also, I was talking to one of my managers today at work.  He sas talking about a sound sheild, and heat sheild that they sell there at the dealership.  Its a little spendy, but, its multi layered stuff that does both heat and sound dampening.  Is there anything you all have seen that does that too, that doesnt cost $5 a square foot..  geez.  Also, does the genny charge the coach battery at all, or does the engine alternator?  Also Denison, is there any need for a fuel pump for the genny? Thanks again.,

Erik

[LVLFNXS]

Sent: 3/15/2004 

OK guys,  Ive got the generator.  NOW, I was looking in the Generator Compartment and saw the gas line, no problem.  Then there was a Black 2 or 4 Guage Wire.  Whats that?  And then White and Black wireset, about 6 Guage wire.  The genny I bought isnt set up for MH use, but itll work.  I wanted to keep some of the receptacles available on the Genny face for power resources, should I tap into the power cord from the genny and split off of it, or what?  I should post some pics of what I am look at so you all see what I see.  Let me get those today, if you have any words of wisdom for me before that, feel free to write.  Thank you all for your advice in advance.

Erik

[denisondc]

Sent: 3/15/2004 11:45 AM

1.  A genset would probably have the fuel pump as part of it.  But they do get old like any fuel pump, so check that this thing runs before you install it. 
2.  The following may be of no help at all: The black and white wire of the same gauge (6 gauge) are the hot wire (black) also known as the "line", and the return wire (white),  also referred to as the neutral  or "load".  In your house and in your RV the white wire should be at ground potential, relative to the ground wire.  Its job is completing the "return" part of the circuit between the supply of electricity, like your genset, and the consumer of electricity, like the things connected to the breakers in your breaker panel. The black wire is the supply of energy from the genset to the breaker panel.  All the black wires in your breaker panel should connect to circuit breakers.   The white wires in the breaker panel might all connect to a junction strip, except the white wire coming from the genset Might connect via a breaker that is linked to the breaker for the black wire coming from the genset.  If there is a heavier gauge wire (2 gauge?) coming out of the generator, it might be the ground wire, or it might be the 12 volt connection for whatever battery starts the genset -2 guage is about the usual auto battery cable size.   There would have to be such a wire of some color, and of course a ground connection for that 12v starting current.  They might depend on the frame the genset mounts for the 12v ground.  I would run a separate ground cable though.  If your rig ever had a genset there should be corresponding wires in it for connecting to the breaker panel.  The other colors for a ground wire are green insulation, or bare copper.  I would assume connect black to black and white to white.   I prefer using red, orange or yellow for my 12v wires.
3.  Words of wisdom:   Have your affairs in order. 

[LVLFNXS]

Sent: 3/15/2004 

Denison,

Here we go.  I have some before pictures of the Genset to start with.  Thanks for all the words of wisdon so far.  It made me chuckle when you said "Have your affairs in order".  It sounded like I was passing away or something.  Anyways.  I havent looked at the wiring from the generator yet, probably will tomarrow once it is off jackstands.  I will get some pictures of the wiring so you know what I got in front of me.  Thanks for your words again,  talk to you later.

Erik

[denisondc]

Sent: 3/16/2004

The rectangular hole is where the cooling air was blown out and away.  The round hole behind it is for the exhaust pipe, and the small hole closer to the door is right below where my crankcase drain plug is.   The heavy black wire would be coming from one of the batteries, so is the 12v source for starting the genset.  And I would add my own 12v ground wire, not depend on the metal framework for that.

[LVLFNXS]

Sent: 3/18/2004

Denison,

I was thinking, since I am not using the electric starting option, since the genny is pull start, Should I just put a 15amp male plug end on the Black and White wires and plug it in to one of my receptacles that are already there?  Would that be OK?  I dont really want to open the wiring from the genny if I dont have to.  I was going to mount that receptacle panel with resets/220/110 anyways to have more options from the outside anyways.  I was also thinking of using the stock gastank for the genny, and mounting it to the ceiling of the genset.  What are your thoughts on these ideas?

Erik

[Ksnarf]

Sent: 3/18/2004

why do you want to use the stock gas tank? hooking up to your main (or aux if you have it) would seem to make more sence as you could fill everything at once.

[DaveVA78Chieftain]

Sent: 3/18/2004 2:51 PM

He is not using a standard MH Gen Set.  Tanks are typically mounted above the engine with them.  I would not be surprised that he has a gravity feed fuel system.

Dave

[denisondc]

Sent: 3/18/2004 3:05 PM

If you are using a gravity feed fuel system from the tank that came with it, I imagine you may need to fill it at inconvenient times; and in inconvenient places like a campground where no-body will want to smell any spilled fuel. I would want a fuel pump that ran when the genset did, and pulled from the big tank. Thats just me. Once at an antique car event we ran the genset for about 18 hours a day, 3 days in a row, it being in the upper 90s and humid. I think it burned just under half a gallon per hour, and used 20 gallons of fuel - and it was worth it.
I also like being able to start and stop it from the dashboard, but that is a minor convenience. Weve never wanted to start it in a drenching thunderstorm storm yet.

[LVLFNXS]

Sent: 3/19/2004 

If I put a small fuel pump on it, should I install a small regulator at the fuel pump in the genset so I dont give it more pressure than its used to? 

Erik

[denisondc]

Sent: 3/19/2004

There are fuel pumps that provide low pressure, like 2 to 3 psi, or high pressure, like 5 to 7 psi. You could buy either type, but unless you knew what the carburetor was expecting, you wouldnt know where to set the adjustable regulator either. If it had a gravity feed fuel system before, I would start with a low pressure pump, one of the 2 -3 psi kind, and see if it ran okay, had a good beige plug color when running under a load, gave no black smoke under low or heavy loads. You could add a regulator later. 

[LVLFNXS]

Sent: 3/20/2004

Thanks denison for your words.  I am going to start tearing the genny apart(separate the frame/gas tank/splitting the wires on sunday.  I will be sure to get pictures of the event.  I am going to mount the present receptacle "face" of the genny in the genset so I may plug into it when I need accessory power, is it a good idea to mount it IN the genset or outside of the genset behind a access door near the genset?  I was thinking because of the heat or whatever.  Do you know what I am asking?  Talk to you soon

Erik

[denisondc]

Sent: 3/20/2004

I would probably leave the outlets that are a part of the genset mounted on the genset, inside the door. This will cut down on weathering of those contacts a little.
Earlier, I think, you had talked about connecting your coach wiring by plugging it into an outlet. The outlets arent designed for permanent connections, nor for vibrations. So I would make the coach wiring connection to the genset at whatever terminals they provided internally for the purpose. I would think those terminals would have to be fairly accessible, since a 5kw genset could provide lots more current than any single outlet could handle without overheating. And in my use of the genset I would plan on perhaps %25 derating; i.e. dont plan for continuous loading of more than 31 amps. The starting load of the roof a.c. wouldn't count, just the running load

[LVLFNXS]

Sent: 3/20/2004 12:33 PM

Well, thank you for your response of that earlier question.  I had already decided to hard wire the genset in to the coach, via a piece of advice from one of my managers at work.  But, as for the genny, its 5000w continuous and 6250w peak it says I believe.  Also, I have multiple voltages there, 110vac(both 15 & 30 amps), and 220vac.  Each rececptacle has a reset(breaker) for it.  Should I tap into the 11vac 30 amp system before or after the breaker for that receptacle?  Also, is the "crossover" for the power separation IN the generator or outside the genny. Meaning, somewhere there has to be a crossover to separate the different types of power, should that be IN the genny, or outside it. Because I have to tap into the 110vac power after that, so I am not getting a default of 220, or a various source. Anyways, I will get pics up here asap.  Thank you for your help.  Last question, has this been done?  Converting a House genny into a hard wired Motorhome genny?  Do you know anyone that has done it?  Talk to you soon.

Erik

[denisondc]

Sent: 3/20/2004 

Erik: You are going to be the expert on the topic of using a non-Rv genset in an RV. A lot of the gensets that are intended for outdoor use don’t have the exhaust and cooling air flowing in directions that lend themselves to being enclosed on all sides. I have to believe there are gensets that Were made to work in either type of environment - with minor changes, i.e. the design took being closed-up into account.
I would presume the "split" for the 110v/220v is outside the actual generator, but inside some part of its housing. I also presume it generates 110v, in two phases 180 degrees apart, using separate windings. If you hook those windings in series one way you get 220v. Hooked in series with one winding reversed, and voila - you have 110v, at double the current. I would expect there is someplace inside its housing where this can be arranged,unless you bought a genset that required an external terminal connections box.
To hook it to your RV wiring, I would make the connection before any of the internal breakers in the genset. This would mean that the (hopefully) existing breaker panel in your RV was the only circuit breaker in the circuit for your lights, you’re a.c., etc. Any circuit breakers that were in the circuit for the outlets that are part of the genset I would leave as they are. No electrician wants to have multiple circuit breakers in series that have the same current ratings.
I would still figure on derating. That 5000w rating is probably based on a power factor of unity. About the only thing consuming power with a power factor of -1- is an electric heater. Anything with an alternating current motor in it has a phase angle between the supplied voltage and current, due to its inductive reactance. 100volts times 30 amps is 3000 watts at a unity power factor, but at a .75 power factor it is only 2250 watts. So your genset is getting as warm as it would be providing 3000 watts, but the energy your roof a.c. gets to consume is 2250 watts. I don’t know what the power factor is for your roof a.c. it would depend on its design and the air temperature - but most of the time I will bet it is lower than .85.
Im sure that converting a stationary genset into a mobile one has been done, but don’t know how well it worked. Like I said, you will be our expert.
You said that it has a rope starter. I presume you have been able to start it that way? I have tried the rope start with my little one-lung 2.5kw genset, and am definitely glad it also has the 12v starter!!!

[LVLFNXS]

Sent: 3/20/2004

Denison,

Well, first of all, I am going to put a "scoop" on the bottom of the genset to ram air up into the genset.  Secondly, I am going to change, extend, and greatly muffle the exhaust.  I am also going to put a small muttler on the intake/air filter to quiet it down.  I am then going to run the tail pipe after the small car muffler out the bottom of the genset and to the rear.  As for the A/C unit, I dont have a roof top one.  I dont have any at all.  So I am not concerned at this point of my max Voltage output.   Thank you for the words so far, I know that this will be a learning time for me and you all.  I will get pictures, and if I have any questions more so, I will ask.. Thank you, talk to you soon.

Erik

[4DWUDS]

Sent: 7/18/2004

Also be aware that some "Job site" generators have a "motion sensor" (if it gets tipped at the work site it turns off, bad idea for a moving RV) and also a overheat sensor.(they dont want you puting it in a bathroom and closing the door to keep the noise down while you run your saw to build the fireplace, also bad idea in a RV genset cubby hole.)

[LVLFNXS]

Sent: 7/19/2004

Hey,

Thanks for your consideration, BUT, its already IN, and configured and working GREAT.  Thanks though

Erik