Generator will not stay running

[Robert Mathis]

Thanks Ed, I went out this afternoon and it cranked up and ran fine. I suspect the slip rings and/or the brushes had gotten so corrosion on them and the Genset just wasn't runniing long enough the clean them off until I tripped the breaker and let it just run without generating any electricity.

[Roland DuBree]

Had similar problem in 2001 Contessa. Thought it to be generator problem. Generator tech ran long battery cables direct from batteries to generator and all ran fine. Had been getting low oil, etc alarms but real cause was voltage drop between batteries and generator due to loose and bad terminal connections at major fuse blocks on engine compartment fie wall. Voltage at generator terminals read 12.5 volts but when tried to start and was running for the short time it dropped to 7 - 8 volts.  Not enough to keep generator running! Over the years the heavy duty battery terminals worked loose and corroded in spite of plastic ring lock nuts.  I replaced all terminal connections top and bottom of heavy duty fuses with washes and nuts. If I remember correctly 7 all together between house and engine batteries.   No problem since, but it drove me nuts for months trying to find and fix terminal points.

Good Luck!

[Jeff Watt]

Finally had mine diagnosed and the conclusion is that the house batteries are not at sufficient capacity to start/run the genset. I have 4 Lifeline 4D house batteries; tech checked two - one bad, the other poor. Didn't bother to check  the other two. They are original so I guess it is time. Going to add this battery monitor from Magnum so I can better see battery status.

http://magnumenergy.com/battery-monitor-kit-me-bmk/

If sitting the magnum remote panel shows good v but as soon as used it drops quickly, I.e. if using a slide. Running the fridge overnight will drop them a lot. So I guess they are not good. Of course we usually plug in so it hasn't been an issue, but was a cause of concern on the way home from Texas especially with inoperable genset.

I'd like to change from house to chassis for the genset as if the house get to low, then genset won't start unless the battery boost is used and secondly the auto genstart can't work as it will only try to start if batteries get to 11v (maximum setting) which is well below what the genset needs to start.

Has anyone with a similar year coach done this? I don't suppose it's as simple as changing the cable at the batteries from the house bank to the chassis bank?

Jeff

[Jeff Watt]

A follow-up to the previous post re. Diagnosis.....

Diagnosis from large rv dealer in texas was completely wrong !!!!

I took the coach to Cummins Western Canada branch in Winnipeg where they determined that the code 13 meant low/no voltage. From the service department:

"Test run - shutting down on code 13. Perform troubleshooting. Excitation field not energizing. Check excitation wiring. Remove panelling from generator. Remove intake assembly. Check brushes - wiring on brush block folded over. Straighten wiring and inspect brushes. Check slip rings. Reassemble and test generator. Good. check AC output, good."

So while at Cummins, I asked whether the generator will run with low battery voltage as that is what I was told was the reason it would not stay running. Essentially the generator has its own power source called the Quadrature windings and this provides power to the control board.

From a Tech: "once the unit is started, it should keep running as the quadrature windings should provide power to the control board. This should be independent of the DC Power."

I know in a related post there was discussion if these generators have an alternator and while I don't know about other types, apparently mine does not.

So although I need to replace my house batteries (they are what starts my generator) as they are long in the tooth and a bit weak, I am glad I didn't by new ones at the dealer and THEN still not have the generator work. I guess I am concerned about the mis-diagnosis as either they didn't  know what the problem was and since it wouldn't start with just house batteries they assumed that was the reason OR, more disconcerting, they new batteries weren't the main reason but wanted to sell me batteries at an inflated price and then still perform tests etc to get the generator to run. The service manager and tech wanted me to stay an extra day or two so they could bring in batteries from another source.

Maybe it doesn't apply in all cases, but in this case it paid to take the problem to a qualified expert. I hope this helps others.

Jeff

Ps. Regarding the diagnosis this is what was provided to me:

"Under voltage - code 13
(After voltage regulation was enabled Output Voltage fell to less than 108VAC (90% of rated) for 5 seconds)

Corrective action:

1. Push the line circuit breaker to Off, start the genset and measure output voltage. If output voltage is normal, the problem is in the circuits external to the genset. If there is no voltage, test for and service a grounded or shorted main, field or quadrature windings (p.10-1) or grounded or shorted voltage sense transformer (p.11-5).

2. Replace the control board (p.11-1).

As your unit is appearing not to be producing voltage, this can be from several area:

        1.  Control Board is Non-Serviciable;

        2.  Issue with Stator:
                a.  The Quadrature windings provide power to the control board;
                b.  Main windings - AC output power; and
                c.  Field windings - create rotating magnetic fields

        3.  Brush Block or slip rings. "