Making some changes to my generator's appearance

[Red Clay Rambler]

Steve,

RV roof air units need a re-inforcement under the opening where they are mounted, usually just 2x4's forming a "box" right underneath the roof hole. If you do it yourself, please talk to a couple of RV shops for tips before you start.

[Rev.Vassago]

I just ordered the Carrier 20,000 btu roof unit. Should be here next week when I get home. Now, where did I put that hacksaw.

Remember - measure once, cut twice. If you cut too big, get the superglue.

Carrier makes a good unit. I was going to get the low profile model if I had the room for it on top of my sleeper. It costs a few hundred more, but the height is a lot lower.

Steve,

RV roof air units need a re-inforcement under the opening where they are mounted, usually just 2x4's forming a "box" right underneath the roof hole. If you do it yourself, please talk to a couple of RV shops for tips before you start.

And make sure you have plenty of home wiring connectors.

(I can't believe nobody has said anything about that to me yet....)


So I now have an in-line fuel filter ($3.50), and an infrared thermometer ($49.99). I stopped at the audio shop where I got the sound deadening material to pick up some more ($40.00 for two sheets), and they pulled the specs on it. It is rated to 400 degrees, so I shouldn't have any issues with it burning(thank goodness).

I think the AC units that the APU companies use are simply inefficient. I've heard of guys with 15,000 BTU APU's who have trouble cooling their cabs, and right next to them there is a guy who has a 12,000 BTU roof mount unit who is freezing himself out of the cab. While I'm sure that 15,000 BTU unit is cooling more, I think they aren't as good at moving that cooled air. That's one of the nice things about where I've got my AC unit located right now - it's blowing right on me, so I'm getting the full effect of it.

[Dispatch_This]

The exhaust runs the entire length of the frame, and exits out the back.


Rev, I would double-check that routing and make sure you don't have exhaust fumes rising up, seeping into the trailer through floor seams, and along the bump rail. Nothing like getting a food-grade load rejected because the trailer is full of exhaust when you open the doors at the receiver.

[Rev.Vassago]

Rev, I would double-check that routing and make sure you don't have exhaust fumes rising up, seeping into the trailer through floor seams, and along the bump rail. Nothing like getting a food-grade load rejected because the trailer is full of exhaust when you open the doors at the receiver.

That's something I never considered, but thanks for the tip. Since I don't haul food grade, that's not much of an issue, but a trailer full of exhaust doesn't sound fun. I suppose I could find another place to have the exhaust exit if it becomes an issue.

[NotSteve]

Steve,

RV roof air units need a re-inforcement under the opening where they are mounted, usually just 2x4's forming a "box" right underneath the roof hole. If you do it yourself, please talk to a couple of RV shops for tips before you start.

Yup, thanks. I read the installation brochure and it needs a 14x14 frame 1" thick which I will have my local machine shop make out of aluminum.

The Rigmaster generator has 2 20amp outputs on it. One goes to your inside cab and the other is used for your engine block heater so that works out well since I won't be using the block heater the same time as the A/C.

[NotSteve]

Remember - measure once, cut twice. If you cut too big, get the superglue.

Measure once, cut twice, measure once, cut twice. Got it.

And make sure you have plenty of home wiring connectors.
(I can't believe nobody has said anything about that to me yet....)

Ya, NO SH**

it's blowing right on me, so I'm getting the full effect of it.

Yup, there is nothing like getting blown directly, can't argue with you there.

[Rev.Vassago]

The Rigmaster generator has 2 20amp outputs on it. One goes to your inside cab and the other is used for your engine block heater so that works out well since I won't be using the block heater the same time as the A/C.

You don't use your block heater and the AC at the same time? What kind of hobby trucker are you?

it's blowing right on me, so I'm getting the full effect of it.

Yup, there is nothing like getting blown directly, can't argue with you there.

I knew that was coming. Get it? Coming? I'll be here all week. Try the veal.

[Doghouse]

Steve also make sure you get the non-ducted model. The one you need has the interior ducting built into to plastic cover. The Ducted unit supplies air through the wall ducts on a class-a rv. So make sure yours in non-ducted.
Putting it in is a breeze, just make sure your hole is as close to a roof support as possible. These units weigh around 80 to 100lbs.

[Kranky]

And yes, I would remove the wing.

That kind of defeats the purpose of installing the generator in the first place, now doesn't it?

Oh yea, one more thing. How long have you had that TV mounted to the wall? I would like to do the same but was wondering about the vibration and bouncing around and just how much abuse those things can take.

It's mounted to a cabinet door, and has been there for about 2 years now. I've never had any problems with it.

It would only be a problem if it was in Peacekeeper's truck.

[Dejanh]

One of the best things i have seen so far in this buisiness, very clean and very nice and just look at how much it ran...


Props up, thats all am gonna say... :!:

[Heavy Duty]

Something else to think about is a automatic transfer switch(RV supply), you can start the generator without turning everything off, the gen runs for about 30 sec and then the power turns on.The transfer switch will also provide for shore power. Didn't notice if you made provisions for a battery charger,also I use a small 1500 watt ceramic heater to heat the sleeper and a second one to keep the cab warm and windows clear.

not Steve, you can get a roof mount AC with the vents and controls on the ceiling panel and then buy a wall thermostat that plugs in to the unit so you can adjust the thermostats and fan from the comfort of your bed.You can also put a heat strip in for heat if you use the wall thermostat.

[Rev.Vassago]

On my way home this evening, I stopped at the local auto parts store and picked up some exhaust heat shield tape. I taped up the first 2 feet of exhaust (about 4 inches past where it exits the box). Hopefully that helps keep the temps lower inside the box.

One thing I've been thinking about all day is - I have an infrared thermometer to tell me what the temp is inside the box, but what is the ideal temp for the inside of the box? How hot is too hot? Since the unit wasn't originally inside of an enclosure, the manual states nothing on the subject.

Any thoughts? :?

[ironeagle_2006]

Most engine oils break down at around 250 degrees. With that one being Air Cooled you want to keep the temps as low as Possible. Also you will need to watch out for Vapor locking also Yes it is a Diesel however it does Evaparate like any other liquid does and if you get an air pocket in your lines they are a PITA to get out.

[Rev.Vassago]

Most engine oils break down at around 250 degrees. With that one being Air Cooled you want to keep the temps as low as Possible.

That doesn't really answer my question. If the temps inside the box got as high as 250 degrees, I'd have more problems on my hands than engine oil breaking down.

[ironeagle_2006]

Sorry Rev misread your question. If I was running this setup I would try and keep temps less than 160 or so. My bad on that one. I cheated I measured the temp on a aircooled Diesel engine here and it was right around 140 with full airflow. You should be ok in that area.

[arky]

Steve, if you look at the top of your sleeper, does it have rivets in it? If so, you should be able to see pretty quickly where your roof supports are. As already mentioned, I would get the unit as close to one of these supports as possbile. You might even want to add a new support on the opposite side if there isn't one within a couple of inches of the unit on that side.

If your sleeper is put together with rivets and your looking for a support, look for the one that has two rows of rivets probably 2-1/2" to 3" apart. That will be your stronger support. It's made as sort of a channel with flanges where the rivets go through. In other words, both rows of rivets are fastening to the same support.

In the end, just make sure that the weight of the unit isn't going to flex the roof enough to cause a leak later on. There's a good chance you'll end up pulling the headliner, all the supports will be obvious at that point. I would probably hold off having the aluminum plate built until you see what your working with. You might be better served with just adding another piece of factory support. I can probably help you out with finding that if you decide that's what you want to do.

I like the roof mount a/c units and would like to install one myself some day.

Arky

[arky]

I'm also wonderinf if anyone has actually measured the fuel usage of their generator..or APU under load. I have talked to several people, even some who claim to run the APU off a seperate fuel tank, but for the life of me, I can't get a straight answer on how much fuel their generator is burning under load. Personally, I don't believe the claims of the APU salesmen.

Example: http://www.cumminsonan.com/rv/produc...e?gensetId=133

If you read through the specs of this Onan 6kw RV generator ( a very popular brand), it plainly states that under half load it burns .4/gal per hour and at full load it burns .7/gal per hour. I can't see spending the money for no more savings than that.

I also can't believe that anyone else is building a generator that provides comparable wattage without burning at least somewhere near the same amount of fuel?

Any comments?

Arky

[Red Clay Rambler]

Sorry Rev misread your question. If I was running this setup I would try and keep temps less than 160 or so. My bad on that one. I cheated I measured the temp on a aircooled Diesel engine here and it was right around 140 with full airflow. You should be ok in that area.

I agree with ironeagle, that temp range is what you want. Over about 175 you could damage the windings in the gen head.

Rev, when I was messing with gen enclosures I would point my thermometer at the gen head in the same spot every time to consistently track results. Also even parking with the gen in the shade will help when possible, even the shadow of the tractor or trailer, anything to keep direct sun off of it.

[RostyC]

And make sure you have plenty of home wiring connectors.

(I can't believe nobody has said anything about that to me yet....)

Rev----->
Don't forget to tape everything real good, a nice big wad of tape at every connection should do the trick. Totally impenetrable!

Good luck with your set up Rev.

[Doghouse]

When I first tested my single cyl. diesel genset, I used the test system (1 gal. fuel tank, and a small radiator) for my motorcycles. The unit used 1 gallon of fuel for 9.5 hrs of run time. It is a single speed engine (2400 rpm.) no matter what the load is.

Right now I am replacing the gen head capacitor and changing the water pump to 12 volt.
This unit has potential, but was designed poorly by the place who went out of business (A-Trans).
I have changed everything on this unit, if I get it to work reliably,..I will be amazed.

BTW most new rooftop A/C units come with a wireless thermostat/remote control, and a heat pump function. The heat pump only works down to like 35 degrees, then its time for the ceramic heater.