spliting the load on shore line

[jlaney]

hello from tyler

just wondering if anyone has split their shour line on their coach. i had some bad days and nights
where the incoming power was so poor that i could not run the a/c . you could count the rpms
of the fan . flea markets are the worst.  lucky to have more than a 20 amps service.
so i run the back unit on a seperate 12 guage to the 20 amp pole receptiable and a 50 amp
shore line to run the rest of bus . if everything fails i still can have a/c . have any thought on
this type of hook up. thanks j.t. laney

[NCbob]

With my 240VAC shore line (50 Amp) I'm putting the front air on one leg and the real air on the other.  If and when I ever add a third AC I might have to move some of the lighter loads around in order to keep the load balanced between the two 120 V legs.

That's the secret whether working with your shore line of a generator...keep the loads as balanced as possible...that way you don't end up running to the 'post' in a torrential downpour to reset the campground breaker all night.

NCbob

[Dallas]

JT,
I too have dealt with flea market 'Bargain' wiring.
Two years ago I took off the rear Coleman 13.5KBtu and the front 13.5KBtu Carrier roof tops. They were noisey, dripped on the side of the bus and pulled lot's of power. I could run both of them on 30A if the fridge didn't come on.
I also had a hole in the curve of the rear roof on my 4103. Being my dumb self, I looked at it and thought to myself, "Self. We can fix this".
I ended up putting an 8KBtu window air in that hole and putting a 4KBtu Window air in the front. Total amp draw is 11.4 amps when both are running.
Right now it's 93° outside with humidity of close to 90%. the front door is open and so are some of the curtains. Inside temp is 79°.
With the roof airs I drew almost 23A,(I think), and didn't get nearly as much cooling.
I think I'm going to mout the front window air in the front of the bus, down by the drivers heat and cover it over with a nice aluminum grill. The rear A/C will stay where it is, but I'll fibreglas over the ratty box I built around it to make it more pleasing to the eye.

[Ross]

Put the rear and middle AC on one leg and the front AC and the inverter on the other.  Basically, everything else that is 120V goes through the inverter.  My reasoning there was that while on a PP I would probably only be able to run two AC's, so I can either run the middle and front which are on different legs or the rear and either the middle OR the front....Or, I can run them all on the genset.  I figure at night, I can close the bedroom door which makes the rear AC perfectly adequate even on low for that area.

[jjrbus]

 If I were to redo my bus, I would not use 2 13.5K A/Cs again. I have a well insulated coach with thermopanes and am sure that these A/Cs are too large. Dallas pulled off 2 13s and replaced them with 12k!!! and he says it works well. Coleman sells 8,300btu roof units that pull 8 amps.  I do not know what the locked rotor amps are, but I think two would work on 30 amps. If my ACs go bad, Ill put the 8's on and let you know the results.
                                                               Work?/Play safely Jim

[jlaney]

thanks for your help
having one of the top a/c on a seperate line is good when im close to another power sourse at a
bluegrass festival or in a trades day park. most of these only give you a 20 amp service and i
can run one off another plug close by. my coach is not a trillion dollar rig. thanks j.t. laney

[belfert]

If I were to redo my bus, I would not use 2 13.5K A/Cs again. I have a well insulated coach with thermopanes and am sure that these A/Cs are too large. Dallas pulled off 2 13s and replaced them with 12k!!! and he says it works well. Coleman sells 8,300btu roof units that pull 8 amps.  I do not know what the locked rotor amps are, but I think two would work on 30 amps. If my ACs go bad, Ill put the 8's on and let you know the results.

You can hardly ever have too much A/C unless it is all in one unit.  My 31 foot travel trailer had a single A/C unit that I think was 15k.  It couldn't come close to keep up boondocking in a field at 113 degrees.  (We burned 45 gallons of gas in the genny that trip and put 72 hours on the generator)  I am putting two 15k units in my bus since it is a lot longer and has the glass in front.

Brian Elfert

[TomC]

Being one for simplicity, I have a 50 amp land line but only use one leg since the bus is wired for straight 120.  That works out to be 6,000 watts.  I can run two roof airs and have some left over.  Most of the time when parked, one roof air will suffice.  I don't have to worry about balancing the load on the two legs.  Since I don't like being hot and don't have an engine run A/C (didn't want to run 40ft of freon line), I have three roof airs.  I usually run the front and back going down the road and the middle one when stopped.  But it's nice to have that choice for meat locker cold if I want.

As far as being in a situation where the PP is iffy, the next inverter I get is going to have the power assist feature where the inverter will automatically kick in in the event of a brown out to help keep the voltage up at 120v.  Also most of these recent inverters also have true sine wave (the only really true sine wave is created by the generator. These new true sine wave are really a modified sine wave where they have made the hertz steps [as viewed on a oscilliscope] finer with many more of them, so the electrical loads don't really know the difference).  That's what I have and what I will do.  You'll do it your way.  Good Luck, TomC