Transfer switch - Page 2

D&MAKAFUN · 07-11-2015, 11:46 AM

OK.....here is the FOLLOW UP on not having AC with the generator running in our 31 UL:
Diagnosis revealed the generator was only putting 46 VAC to the transfer switch. The tech then traced the wiring. There is a junction box located behind the generator. I believe it is mounted on the frame or between the frame and the drive shaft.
A bad connection on the neutral wire was found.
Once secured, the generator puts out 120 VAC and all is cooling perfectly.
For those of you who have had off again, on again with AC power on the road with your generator on, I would certainly start with that junction box and connections.
Hope this helps,
Darrell

Wilcut · 07-12-2015, 07:36 AM

Thanks Darrell, I have a folder where I'm putting all this good stuff for latter reference.

Thanks again.

Don

D&MAKAFUN · 07-12-2015, 07:46 AM

You are welcome Don. It sometimes seems a bit overwhelming when "stuff" just keeps malfunctioning. I was once told by a certified tech that our systems are basically experiencing a tornado and earthquake each mile they travel down the road. I was also told "80% of the things that go wrong with an RV are simple fixes with the vast majority fixable by DIY".
I have a folder too..............it has become quite large. LOLOLOLOLOLOL
Keep on keeping on and have fun as you go,
Darrell

Wilcut · 07-12-2015, 07:48 AM

Same to you and yours!!!!
Don

JoeMazz · 07-13-2015, 01:59 PM

Anybody know how much stuff you can run with the generator while driving. I don't know the math. Can both ac's run off the generator with the fridge and micro? I had the generator issue on my trip out west. everything would kick off while the generator was running; fridge would trip to gas; then come back on later. Didn't know if it was because I was running too much stuff, but breakers never popped.

Jacobsnc · 07-13-2015, 02:25 PM

I would think that running all you mentioned at the sane time would be at the limit or above what the generator can handle. In the On an book is a load chart you can check. I normally run both ac units and the fridge with no trouble.

AugerN · 07-13-2015, 02:36 PM

I know that we've traveled with the gen running. Both AC's, fridge running, and intermittently used the microwave with no problems. But I haven't done the math!

JoeMazz · 07-13-2015, 02:56 PM

I didn't try to run both ac's again after the first time it went down. 1 ac wasn't enough to combat the heat during tge many 8 hour drive days heading out west. It was 80 something in the RV the whole time.

D&MAKAFUN · 07-13-2015, 06:30 PM

Joe, The generator experience is all new to me so the manual is my only source.
The spec page indicates 5500 watts @ 3600 rpm. To me that means max output.
Then in a few spaces it states 2400 rpm. So would 2400 rpm be normal operating speed?
If that is the equation.....3.7 Loading the Genset, Table 2....typical appliance loads lists the sppliances & load in the manual.
So using that table, if you have 2 ACs on & the fridge, you could possibly be using 5000 watts of power or real close to max output.
I have operated 1 AC, fridge & a box fan going down the road.
Is my math right?
Any insight would be appreciated.
Darrell

D&MAKAFUN · 07-13-2015, 06:43 PM

Also, we don't rely solely on the ACs blowers and use our box fans to move air. When on the road we also shut all ceiling vents except 1 in the hall & 2 closest to the cockpit. That helps force the majority of air to the front.
Our equation with only 2 days exception, is there are only the 2 of us on board.
More people generate more heat. We have also been really fortunate to travel in mostly under 92 degree temps....NOT driving directly into the sun.
A lot of variables

JoeMazz · 07-15-2015, 05:32 AM

My dash ac is pretty much useless when the engine is hot. Between the heat from the windshield and the engine heat I get very little from it. Anyone else find this to be true?

AugerN · 07-15-2015, 07:19 AM

Mine works well. I keep it on coldest setting with Max AC and rarely turn the fan beyond the first or second setting. Kept cool driving in mid 90 ambient temps. Keep in mind however that we always run the gen and roof AC's while driving as well.

D&MAKAFUN · 07-15-2015, 12:16 PM

Yep anything above 85* dash air can't keep up. Like AugerN said...using the gentec & rv air keeps it very comfortable. Prior to leaving in the mornings we run the rv ACs to try to lower the coach temp. Then as soon as we start the motor, the dash AC goes on. Any stops during the day we turn on the gen & house air while we are away. That way the dash AC isn't trying to catch up. We also pull shades to meep the suns rays from heating the interior.

McGarrett50 · 07-16-2015, 07:46 PM

Good discussion everyone. Thanks. Before departing on a trip, we plug in our Precept and run the A/C and Fridge overnight. Typically we'll leave in the morning and the coach is cool inside and as Darrell said, the Dash A/C just blends in and we stay cool.

We live in Florida and manage heat reflection as much as possible.

Going to incorporate the vent management Darrell shared. That should help even more.

Cycledoc675 · 07-16-2015, 09:37 PM

I noticed on my recent 2000 mile trip in my 29UM that when both air conditioners were running after a long leg in hot weather, I would have trouble. One would turn off after reaching desired temp. But when it tried to restart, it seemed it couldn't overcome the inrush startup demand, causing the converter to click and kill power to both air conditioners. once I cut them both off then started only one of them, all was fine. Now I had previously installed hard start capacitors to both AC units. I bet if I didn't have them, I would probably not been able to start either. There seems to be a lot of heat building up under the coach during extended hot weather driving from a combination of the road, engine, and generator that is evident when you run some cold water...and it comes out piping hot. My total guess as a non-electrician that this heat is effecting the ability of the generator to run both AC units.

AugerN · 07-17-2015, 06:01 AM

Tell me more about the hard start capacitors. What's the need/benefit? And is it something the dealer did or you did?

D&MAKAFUN · 07-17-2015, 02:26 PM

Quote:

Originally Posted by Cycledoc675

I noticed on my recent 2000 mile trip in my 29UM that when both air conditioners were running after a long leg in hot weather, I would have trouble. One would turn off after reaching desired temp. But when it tried to restart, it seemed it couldn't overcome the inrush startup demand, causing the converter to click and kill power to both air conditioners. once I cut them both off then started only one of them, all was fine. Now I had previously installed hard start capacitors to both AC units. I bet if I didn't have them, I would probably not been able to start either. There seems to be a lot of heat building up under the coach during extended hot weather driving from a combination of the road, engine, and generator that is evident when you run some cold water...and it comes out piping hot. My total guess as a non-electrician that this heat is effecting the ability of the generator to run both AC units.

Sounds very logical Cycledoc. I would also be interested in the capacitors.

Cycledoc675 · 07-18-2015, 06:11 AM

Installing Hard Start Capacitor into my RV Air Conditioner
RV Air Conditioner Hard Start Capacitor | ModMyRV
Hey guys. The AC units on our Precepts are basically Coleman Mach 3 units distributed by AirXcel. If you were to buy the unit off the shelf, you would likelyi have the hard start capacitor. But OEMs tend to eliminate them to save a few dollars. The good news is that they are CHEAP and VERY EASY to install. I was trying to see if I could start and run an AC unit off of a 2500 watt inverter generator as a backup, but I could still never get it to work....I suppose because the Progressive Dynamics IntelliPower converter in our units simply would not respond fast enough to the surge demand to ramp up my generator fast enough. Look at the 2 links and see what you think. There is an "E" type and a PTCR type as well. I installed the E in the front unit and the PTCR resistor type in the rear unit....can't tell the difference. They both anecdotally seem to start easier.

**norty1** · 07-18-2015, 06:21 AM

Safety tip from an old electronic tech, CAUTION : Never put your hand across the terminals of a large capaciter. They store energy and can give you a Start too!

AugerN · 07-20-2015, 06:42 AM

Again pardon my lack of knowledge but what is the benefit of the capacitors and what is the downside to not installing them? Is it just that repeated hard starts are bad for the overall longevity of the units? And what conditions might cause a hard start? All I notice is that the AC units kick on. I have not noticed any difficulty starting up.

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