Generator help needed part II

belfert · June 23, 2013, 12:56:56 PM

I have a Powertech 8CSI generator with the quiet enclosure. It provides 120 volt on both legs just fine with no load. I can start one A/C unit just fine and the voltage stays up. If we turn that single A/C unit off and then turn it on again the A/C unit won't start and the voltage drops way down. The same thing happens if we try to start a second A/C unit. We checked the amp draw on both A/C units and they are just fine. Both A/C units work just fine on shore power. They also work fine on a 6,500 watt Yamaha generator I have here.

I had this problem earlier this year and Powertech thought it was the brushes. I bought and installed a new brush assembly from Powertech and the problem still remains.

Could this be a regulator issue? A friend of mine was looking at this today who does lots of electric forklift onsite service work and was seeing some strange things, but without talking to Powertech he wasn't sure if what he was seeing was normal. I will call Powertech in the morning. Thanks for any help on this perplexing issue.

wg4t50 · June 23, 2013, 05:58:07 PM

Sorry I could not get back sooner, my Ipad is not good for sending messages.

As for the brush type generator you have, I would have to assume the voltage regulator is the issue, Assuming it has a regulator, do not think they used the capacitor type regulation, or maybe poor connections between the brushes and the regualtor.
One point to remember, once you have an air conditioner running, stop it and try to restart it within about 3-4 minutes, it has an issue with head pressure, this will most likely stall a generator or trip a breaker. If you can give it a few minutes so the head pressure goes away, it will start much easier, Maybe your a/c units already have this time delay function, older units do not, newer units most likely do.

Anyway, Iwould be checking the regulator, it sounds lazy for sure (defective)
If you can find the part number on it, we can get the correct replacement for it, if you are having a problem with parts.
Good luck
Dave M

belfert · June 23, 2013, 06:43:31 PM

Could an RV dealer diagnose a bad regulator? I would like to be sure the regulator is bad before shelling out $250 for a new one. The only service dealer Powertech shows in Minnesota is a 5 hour round trip. Powertech generators are used in quite a few Class A motorhomes so you would think someone in a metro area of 3 million people could service Powertech generators.

Powertech has the regulators in stock. I would like to see if I could find the part number as I think I could get it for less if I could find that. I see lots of similar looking regulators on Ebay.

belfert · June 24, 2013, 05:57:06 AM

The part number on the regulator is listed as XQW250-S2 U/F It appears the only place one can get this regulator is from Powertech directly. I could not find any other part number.

I talked to technical support at Powertech just now. The guy I talked to wanted to know who said to replace the brushes as he said that is not the issue. He said the regulator or something inside the generator end itself is bad. He gave me a way to diagnose if it is the regulator or something else. I'm hoping just a regulator and not the end for $1600. I will have a motor repair shop look at the end if that is the problem.

luvrbus · June 24, 2013, 06:11:52 AM

I have a ONAN the magnets came loose inside the head and caused the problem it was cheaper for me to buy another generator ONAN wanted 3800 to repair it the new propane generator was 3200 with shipping sad part was ONAN knew they had the problem and never told anyone could be the case with you also

chuckd · June 24, 2013, 06:44:09 AM

B: got the same gen set and the same problem. Will get back to you later today with what I have tried, but pretty sure it is the regulator.

Chuckd
Stillwater Mn
1979 Prevost

belfert · June 24, 2013, 07:55:21 AM

The generator cost me $6,000 so $1600 for a new generator end would be worth it in this case. It would be a lot more than $6,000 for a new generator today.

Powertech told me to disconnect two leads from the regulator and connect one to ground and one to 12 volt positive. (Don't have my notes on which lead goes to positive/ground.) The generator should put out a steady 100 volts with this config. If it puts out a steady 100 volts the problem is almost certainly the regulator. If the voltage wavers the problem is within the generator end. The breakers have to be turned off so no load goes to the generator since there is no regulator during the test.

wg4t50 · June 24, 2013, 08:47:51 AM

The part number, is that a Power Tech # or any idea who made it
?
Dave M

wg4t50 · June 24, 2013, 08:53:25 AM

OK, Just found it, it is available from Power Tech. $215.00
Give em a buzz
Dave M

belfert · June 24, 2013, 09:12:17 AM

Quote from: wg4t50 on June 24, 2013, 08:53:25 AM
OK, Just found it, it is available from Power Tech. $215.00

Yes, I already mentioned I can get the part from Powertech. I think their price is too high, but it is what it is. The generator head is Marathon so it might very well be a Marathon regulator, but it is not labeled as such.

I'm not going to order a regulator until I do the test that Powertech told me to try.

belfert · June 24, 2013, 06:26:53 PM

Okay, I applied 12 volts to the brushes and got a steady 36 volts AC on both poles. Powertech said it should be 100 volts. I tried running it with the brushes disconnected and I only got 3 volts. (I wanted to be brushes are making contact.) Since the voltage stays steady I am wondering if Powertech told me the wrong voltage to look for?

I am leaning towards the regulator, but my friend who works on electric forklifts for a living thinks it might be the head. Time for another call to Powertech in the morning.

belfert · June 25, 2013, 05:52:09 AM

Powertech support is pretty certain it is the regulator. They said they would work with me if it was not the regulator and I needed a head instead. I am going to have them overnight it as ground is $18 and overnight is only $36. I need to get this thing fixed soon as I leave in three weeks.

chuckd · June 26, 2013, 07:19:06 AM

Brian, I have an earlier model of the same gen set. My issue is that it would not start my Cruise Air ac (Clifford said it wouldn't

) but it still acted flakey. Voltage would drop way down on one leg. Suggested it was a bad regulator, got a marathon se350, same darn regulator as the one that did not work. So that is a different regulator than the one you ordered, will call powertech and see what they say about my issue - again.

Chuckd
Stillwater Mn
35 Foot Prevost - Shorty and Porky

belfert · June 26, 2013, 09:33:07 AM

The SE-350 appears to be different than the regulator I have. Mine has terminals for 120 and 240 while the SE-350 has terminals for 50 hz and 60 hz. I suspect Powertech had their own part number attached to a generic regulator so you can't buy it elsewhere.

My new regulator was delivered about an hour ago according to Fedex. I'll give it a try as soon as I get home tonight. My generator seems to drop voltage on both legs so your problem may be different than mine.

belfert · June 26, 2013, 04:44:46 PM

The regulator fixed it! The voltage is pretty high at 132 volts unloaded and 125 volts with the two roof airs running, but I can tweak that yet. I was able to start both roof airs with the voltage not dropping. I'll put it back together tomorrow and let it run for a while to make sure the regulator doesn't die right away.

The regulator seems to be some generic Chinese item as the box it came in has all Chinese writing on it except the model number. I wish it was a Marathon SE-350 regulator as those are common and less expensive.