Kerstner A/C amps?

[CaptnALinTiverton]

How about running the rooftop AC on the alternator instead of the generator in lieu of running the engine AC for heavy load hill climbing? I wonder what would be the difference in engine loading?


AL

[onemanvan]

My best guess would be the Kerstner roof A/C probably only consumes 5 to 10 horsepower. However - that is not my concern. My concern is how HOT the alternator positive output terminal/stud gets. From a cold engine start the stud on my alternator got hot enough to burn my finger. That was after only 10 minutes of running the roof A/C. Anytime an electrical connection gets that hot I'm thinking something's not right...

[discus]

I always wondered why they used small diameter cables at the alternator. A 200A alternator needs at least a 2/0 AWG preferably a 3/0 AWG cable and this is way smaller than that. Probably a 1AWG.


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[onemanvan]

Good point - the cable[s] look undersized to me as well. Couple that with a potentially bad crimp on the ring terminal[s] and excessive heat build up is unavoidable at such high currents. Maybe it's an OEM cable sized for a smaller stock alternator? Replacing it with a better/larger cable has been on my list of 'fun things to do' for a long time. Meanwhile I've been avoiding running the roof A/C off the alternator.

[CaptnALinTiverton]

Cable length has a lot to do with it too. It's ohms per foot so for short runs, less diameter is required, but connection resistance is important. However just because a connection feels hot, the heat felt is not an accurate indication of loss; it needs to be measured, best by measuring the voltage drop across the connection. In the case of a ring-tongue terminal, measure inside cable at lip of terminal to stud center. Divide voltage by current clamp reading to get resistance of connection. A great source for wiring info is on the West Marine website.

AL

[OldWest]

Thinking aloud.

Dr. A suggested that the harmonic balancer may be prone to breakage/tears on the Sprinters with a factory rear AC unit. Apparently, there is a second drive belt on the engine for that factory engine driven rear AC unit, so more wear and tear on the harmonic balancer (think that was the issue). Think the recommendation was to inspect/replace at 85,000 miles?

Guessing--but I wonder if our larger 200 amp alternator works harder and puts more wear/tear on the harmonic balancer if the Westy 12 V Kerstner AC is being used? If so, OneManVan's idea of running rear AC off generator may be a good idea (offset by the everlasting debate about propane tank valve not shut and using propane when in motion).

Non-mechanic's understanding: The harmonic balancer is the rubbery mount for the crankshaft pulley--it holds the outer metal circumference of the crankshaft pulley to the turning shaft in middle of pulley. The problems are the middle keyhole retaining part breaks or the rubbery part near the circumference/outer rim cracks and breaks--so the pulley falls off.

[tneuer]

I've got 2 power supplies if you or anyone else needs them.

Tom

[Riptide]

I might take you up on one, Tom. I gotta find another day off to get back in there.

[512Westy]

Re-reading this string and see Old West's comment about sourcing the belt. A couple of us have bought them. i looked up the info in the yahoo database for replacement parts. This doesn't look familiar but i'm not home this summer to check what i bought. But there is a write up by vince i think on the model number and source we both bought from...

Rooftop AC

Compressor belt

PK-630 belt

Kerstner Scott Carter 1-972-418-6444

[Riptide]

Funny you should bring up the belt; I recently contacted PIX North America to see if they could find me a new belt. I gave them the info off the my current belt, and this was their reply:

>>>>>>>>
I am looking for information on how to source replacement belts for a rooftop air conditioning unit. I, and about 250 other owners, have a camper built by Westfalia, in Germany. These campers were equipped by an aircon unit made by Kerstner.
The units use a ribbed belt with the following markings: (a picture is attached)
PIX ‘X’power - K 630 G jg 51
As our units are over 10 years old, we Westfalia owners are having some difficulty finding OEM belts.
Can you assist?

>>>>>>

Good afternoon Pat,

Our apologies for taking several days to get back to you on this belt. We had to do some digging back in our records to figure out which belt this was. Fortunately we were able to come up with the answer this morning. The belt you’re after is going to be a PIX X’ceed P060630E. Would you like us to find a dealer close by to you who can get this belt for you?

Have a great weekend.

Regards,

Julius Cook
O-217-516-8348
julius@pixnorthamerica.com