7.5 onan generator - EMS electrical problem

[suemac1]

Hope to get your help with a 7.5 Quite Diesel generator/electrical issue. One magnet on the rotor de-laminated and took out the stator causing a failure. The question I have is concerning the EMS system. We have removed all electrical components associated with our generator problem and all parts sent away for rebuild or replacement. The Coach was plugged in to shore power but indicated zero readout on the EMS system ie. no power I.D. Does anyone have ideas on what might cause this issue? I can hear the battery charger and can confirm '120 volts at outlets' but no indication of power at the EMS. HELP....PLEASE!!!

Doug

[RV Wizard]

Doug, we need to know what year make and model of coach you have and the make and model of the EMS as well. Can you trouble shoot if the schematics are present?

[suemac1]

Mike....Thanks for the reply. We have 2004 Monaco Windsor. As for the EMS, it's a 50 amp Smart EMS. Right beside this read out unit is another readout unit labelled XANTREX by 'intellitec' which provides information regarding the converter, charger, batt full and error. It also has the numbers/letters 'RC7 G5 Remote control/Gen Starting' on it. Does this information help?

P.S. Doug is at work right now and asked that I (his wife who knows nothing about this stuff!!!!) provide this information to you before he gets home!! Thanks
Susan

[Poptop]

If you are talking about the power meter display on the panel inside of the coach not showing any power available, but you have house current when plugged in, I had the same thing happen to me. Turns out I had a wire come loose from the back of the power display. I re-plugged it in and the display meter worked. You may have a similar situation, or there may be a blown fuse that controls the meter. Good luck

[RJay]

If you have the automatic start feature on your xantrex you should disable it until you get the generator fixed.

[RV Wizard]

There are pdf files of some of the Smart EMS systems under the button "Files" neat the top of the page. If you don't find an easy reason, like, a loose connection maybe this will help.

[suemac1]

First and foremost....Thank you for the replies everyone!! We will be checking the wiring and disabling the xantrex. We can always count on answers that really help from this forum!!

Doug and Susan

[RJay]

Please keep us posted on your progress.

[suemac1]

Just a thought, since I have disconnected all electrical leads and load wiring from the generator as well as complete removal of the control module, would the EMS not register voltage because L1 and L2 have been isolated, hence no circuit ??

Doug

[Sightseer 27]

Quote:

Originally Posted by suemac1 Hope to get your help with a 7.5 Quite Diesel generator/electrical issue. One magnet on the rotor de-laminated and took out the stator causing a failure. The question I have is concerning the EMS system. We have removed all electrical components associated with our generator problem and all parts sent away for rebuild or replacement. The Coach was plugged in to shore power but indicated zero readout on the EMS system ie. no power I.D. Does anyone have ideas on what might cause this issue? I can hear the battery charger and can confirm '120 volts at outlets' but no indication of power at the EMS. HELP....PLEASE!!! Doug

I would be interested on how this all worked out in the end if you care to share. I have a 7.5 sitting in my yard out of my friends Gulfstream Constellation ('99) that let go in the same fashion. With $2,000.00 in repair parts not knowing if the inverter had been taken out with the catastrophic failure he opted for a new generator-$8,000.00 not fun. We swapped it here in the yard so that was no shop time. His EMS showed odd readings but nothing that came in as a concern. The one possible difference is that he was only plugged into 30A shore power.

[suemac1]

Just as an FYI, I brought the stator in for testing this week and it is toast. Priced a new one at around $1,500 so we decided to have it re-wound which will be approx $650. It will take about 2 weeks for the re-wind job. A new rotor will be around $500. Our only outstanding issue will be cleaning all of the shrapnel from the electrical circuitry. I will keep posting our progress. Thanks all!!

Doug and Susan

[suemac1]

As an update to our first post, we finally have everything back to working order. As mentioned, the stator was rebuilt, a new rotor purchased. We put everything back together with the help of pictures that were taken while we disassembled everything. With it back in place, we tried the generator again, but it failed to turn over. All we heard was clicking sounds. After rechecking all the connections we had made, we tried the battery boost button within the coach. At this point, it tried to start which was an indication that the house batteries may be toast. We checked then with a voltage meter and found that a few below the normal reading. So....we purchased 4 new 6 volt deep charge batteries. After again, taking notes and pictures of how we took them off, we replaced them and VOILA....the generator turned on, purring like a kitten.
We have learned sooo much about some of our systems, such as house batteries start the generator not the cranking batteries, (duh) the EMS appears to need gen wiring to indicate load or usage. Lastly take lots of photos, notes and have confidence. Also it really helps to have a great partner to keep you from leaping from the ledge during those frustrating moments.

Doug

[RV Wizard]

Great to hear you are making progress on the learning curve and the the generator is now working. On the EMS and generator; With the generator as the power source the need to shed loads is not an issue. Therefore, the EMS will not come into play. However depending on which EMS you have an LED for the generator might/should be on. Good luck and keep us posted.

[suemac1]

Thanks Mike,
So far all is good. Our EMS situation seems to be o.k. since all of the appropriate wiring was installed. The generator runs fine now and hopefully will continue. Of note, the electrical professional that rewound our Stator asked us some technical questions concerning wattage output. We shared that the unit was a 7.5 kw diesel. His feeling was the wattage should be closer to 4 K watts due to the wire used on the Stator. All we know is it indicates 7.5 kw QD diesel onan generator. One interesting thing we noticed is that the breaker on the gen. is set at 35 amps. you would think a 7.5 kw would be closer to 60 amps. GO FIGURE!! Anyone that would shed some light on this issue please join in.

Doug