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Two Generator Questions

Two generator questions — and I'll add the caveat here I saw in another post about generators: "I am not an electrician."

    • Our generator (Powertech 10KW, Isuzu 3-cylinder diesel) was working perfectly. However, after running the generator several hours while dry camping on a 100+ degree day, something happened. The result is 0V on Line 1, with a 120V reading on Line 2. The air conditioner on Line 1 stopped, so I don't think this is an indicator panel problem.  I've checked with a friend who works for a full-service Cummins shop, as well as a tech at the nearby Powertech service center. Guesses range from the Line 1 circuit breaker (which on ours is "bound" or slaved to Line 2), to the voltage regulator, to something on the circuit board. Anyone else experienced this 0/120 situation?

    • The same 100+ degree day, the generator's remote radiator (rear-facing radiator in side bay with fan) boiled-off what appeared to be about a quart of coolant through the overflow hose. I'm worried about restarting the generator even to test it or diagnose the problem because I suspect an air gap at the top of the radiator. I've watched a more experienced FT owner top-off coolant in a system that was low by adding coolant into the pressure cap opening near the generator itself, until coolant emerged from the petcock on top of the remote radiator. But is the step-by-step procedure for doing so simple enough I can do it? If not, I want to provide a heads-up to whoever ultimately services the generator, if they aren't familiar with the procedure.
    [/list]

    Susan & I will gradually learn to maintain — even repair! — more systems in our coach, but it has been a steep learning curve over the 60 days since we acquired it. We're particularly concerned about the generator because her father's health is declining somewhat rapidly and we can only dry camp near where he lives. We may need to make a trip at any time.

    Thanks in advance for any guidance here! I just want to be sure we aren't taken to the cleaners on this repair — or even with the very best intent on the part of the shop, that they don't go down some dead-ends members of this Forum might identify.
    The selected media item is not currently available.Richard & Susan Peck
    ____________________
    1999 40' U320 "Bob Patrick"
    (2000 4010 U320 WTFE Floor Plan, Single Slide)
    Build #5567  |  MC #17522

    Re: Two Generator Questions

    Reply #1 –
    Richard,
     
    In regard to question 1
     Have you had a chance to plug in to a 50 amp power pedestal after this occurred?
     If so did you have power back on both legs?
     If you are comfortable working around electricity you need to check the contacts in you transfer switch to see if you have power coming at least to there from the generator while it is running. You could have burnt up a contactor in your transfer switch and nothing is wrong with the generator itself.

    Question 2
    While all this was going on did the radiator cooling fan trip/ quit running when you lost power? If so you may have just boiled the antifreeze due to no cooling fan.  If this happened then your power problems may be in the generator end rather than the transfer switch end. 
    Your generator also has a water pump belt. That belt needs to be checked as it may have broken causing the engine to overheat.
    Did the generator shut down on overheat or did you kill it at the switch before it shut it's self down?
    On our Isuzu it has 3 places to bleed air out of the system if you don't have antifreeze at all the air bleed pet cocks it will get hot also.

    This is just several things to look at to help narrow down your problem.

    Pamela & Mike
    Pamela & Mike 97 U 320

    "It's not what happens to you, but how you react to it that matters."

    Re: Two Generator Questions

    Reply #2 –
    Pamela & Mike,

    Thanks so much for your post.  I did connect to a power pedestal when our dry camping experience was over (we're connected now). Both lines show 120V.  Inverter and charger are working.  None of that seems to have been affected.

    Re: #1:  Sadly, I'm not sufficiently competent with electricity to check whether power is continuous from the generator through the transfer switch, but that's a good suggestion and something I can offer as a heads-up when I take the coach for service.

    Re: #2:  Apparently the radiator fan quit during the 100+ degree day, when we lost power.  I say "apparently" because several things were going on at the time (the coach was parked at the loading docks behind my wife's office; she was bringing out a colleague to see our brand new home — what a first impression!; I'm trying to figure out why the front air-conditioner quit; and red coolant is running across the parking lot). It wasn't my finest hour. In short, I don't remember the exact sequence of events.  I do remember manually shutting down the generator before the over temp auto-shutdown could.

    However, when it was all over and we were in a cooler locale, I did discover the generator fan breaker had popped. So that suggests (if I understand) that the problem is potentially at the generator end. 

    Finally, none of the belts are visible on the generator of our coach. The generator tray (wrong word?) is bolted down. The oil can be changed by taking four bolts out and dropping the "belly skin" (what would be the correct term?) below it. But if the belts are only visible from the back, I'm afraid I can't check. 

    With thanks again for pointing to possible causes!  Much appreciated.

    The selected media item is not currently available.Richard & Susan Peck
    ____________________
    1999 40' U320 "Bob Patrick"
    (2000 4010 U320 WTFE Floor Plan, Single Slide)
    Build #5567  |  MC #17522

    Re: Two Generator Questions

    Reply #3 –
    On our 1997 U295 with 10K Powertech/4 cylinder Kubota, the tray on which the generator is mounted will slide forward several inches. There is one bolt on each side of the tray the holds the tray in place. You will have better access if you are able to slide the generator forward from the cabinet.

    The breaker for the electric motor for the remote fan on our generator got weak over time and would open up prematurely. That would stop the blower for the radiator, and the generator would shut down from the overheat protection. I bought a new breaker from FOT. The new breaker was easy to install and works reliably.

    J D Stevens
    1997 U295 CAI 36' Build #5085
    2002 Subaru Outback
    Motorcade 16869
    Bellville, TX

    Re: Two Generator Questions

    Reply #4 –
    Richard. Go to the generator and cycle the  breakers on the front. You may have tripped one side and that could very possibly have caused the cooling fan to shut down giving you the second problem.
    Gary O
    2000 U320 4210

    Re: Two Generator Questions

    Reply #5 –
    Also,,, Richard ,  Please call. I failed to save your new number.  We need to talk.
    Gary O
    2000 U320 4210

    Re: Two Generator Questions

    Reply #6 –
    ...and if you find this is the issue, it could be because you ran too many high powered appliances or systems at once, it may continue to trip until you cut it down & use fewer at a time, i.e. one AC or one high wattage coffee pot or the microwave but nothing else, etc.....mine kept tripping & I found the coffee maker was using more power than the microwave.

    Re: Two Generator Questions

    Reply #7 –
    J.D., Gary, Miz Dani —

    Thanks to all!  Gary, I did cycle the breakers several times, but no luck.  Miz Dani, you would NEVER load up your system beyond capacity would you? <big smile and wink; see you soon> And J.D., thanks — I'll try the bolts and gently sliding the tray out. I suppose it's also possible the breaker has gotten weak and cycling it several times wouldn't have cured the problem?

    Finally, Gary, I'll phone on Friday. If you are busy, no worries. You have so much going on I haven't wanted to bother you after all your kindness when we passed through TN.

    With big thanks to all!
    The selected media item is not currently available.Richard & Susan Peck
    ____________________
    1999 40' U320 "Bob Patrick"
    (2000 4010 U320 WTFE Floor Plan, Single Slide)
    Build #5567  |  MC #17522

    Re: Two Generator Questions

    Reply #8 –
    Generators are optionally wired two ways, and can be easily changed to either way:

    A.  220 volts with two separate legs, not tied together, with neutral carrying the DIFFERENCE between the amps being drawn on each leg.  This way is the same as a house is wired.

    B.  Two 110 volt legs that are tied together within the generator box at the circuit breakers.  In this case the neutral carries the SUM of the amps being drawn on each leg.  This is a non-standard way that works well with generators when on leg has high power demand and the other leg has a low power demand, but it risks overloading the neutral when both legs carry very high power.

    Re: Two Generator Questions

    Reply #9 –
    Quote from: Barry & Cindy –
    Generators are optionally wired two ways, and can be easily changed to either way:

    A.  220 volts with two separate legs, not tied together, with neutral carrying the DIFFERENCE between the amps being drawn on each leg.  This way is the same as a house is wired.

    B.  Two 110 volt legs that are tied together within the generator box at the circuit breakers.  In this case the neutral carries the SUM of the amps being drawn on each leg.  This is a non-standard way that works well with generators when on leg has high power demand and the other leg has a low power demand, but it risks overloading the neutral when both legs carry very high power.

    Do you have some documentation on this? What you say in "B" is true for a Multi-Wire Branch Circuit (MWBC) when wired from the same phase...but most generators have multiple windings and requires two or more phases to get rated output, right?

    Here's a good lesson for the curious too that I came across a few years ago: Help understanding neutral conductor.
    1998 U270 34'

    Re: Two Generator Questions

    Reply #10 –
    Quote from: krush –
    Do you have some documentation on this? What you say in "B" is true for a Multi-Wire Branch Circuit (MWBC) when wired from the same phase...but most generators have multiple windings and requires two or more phases to get rated output, right?

    Here's a good lesson for the curious too that I came across a few years ago: Help understanding neutral conductor.
    http://www.beamalarm.com/image/Generator/generator_diagram_110vac.jpg
    Technical Help - Generator

    There is a wealth of information on Beamalarm.com.
    J D Stevens
    1997 U295 CAI 36' Build #5085
    2002 Subaru Outback
    Motorcade 16869
    Bellville, TX

    Re: Two Generator Questions

    Reply #11 –
    Powertech service manual documents how the same generator will output separate phases where there is 240v across both hot legs and what changes to make to tie both legs together where there are 0v across both legs.  This is not a difficult change-over.
    Some coaches have been one way and some use the other way.  Usually smaller generators use 0v and larger generators use 240v.

    Re: Two Generator Questions

    Reply #12 –
    Unless you have a need for the 240 Volt, you will be a happier camper with the simple 120 Volt configuration.  the voltage will be more stable, less voltage dip when starting a heavy load such as the heat pumps, even the microwave when the a/c is running.  Having both coils in-phase, less heating in the generator end and zero concern about balancing the load. :dance:

    Re: Two Generator Questions

    Reply #13 –
    Quote from: Dave M –
    Unless you have a need for the 240 Volt, you will be a happier camper with the simple 120 Volt configuration.  the voltage will be more stable, less voltage dip when starting a heavy load such as the heat pumps, even the microwave when the a/c is running.  Having both coils in-phase, less heating in the generator end and zero concern about balancing the load. :dance:
    Dave,
    Now that's some excellent practical advice. Thanks for posting.  ^.^d
    Rick
     

    Re: Two Generator Questions

    Reply #14 –
    Dave sure explained the advantage of "simple 120 volt configuration".  There is a minor disadvantage of this configuration that does not offset Dave's advantage, because the single neutral wire carries the full amp load, which should not be over 50 or 60 amps.
    Some transfer switches, like the popular ATS-100 often have 40 amp limits on their generator neutral wire, further limiting the max safe amp draw.