I think I have narrowed this problem down to a faulty aux contactor solenoid on the shore power contactor which is what controls the generator. Now I have a question about what purpose they serve? My understanding was they keep the shore and generator power separated, but isn't that what the manual switch above the driver does? The solenoids engage sending power to the other coil terminal magnet which make it contact only after you flip the switch. So is there any reason why they couldn't be bypassed altogether?
(09-10-2016, 07:51 PM)Fulltiming Wrote: The auxiliary solenoids are a safety device to prevent connecting the shorepower and the generator together if a relay jams.
Yes, but then the fuse would blow and cut off the power.
Bypassing them would allow the possibility of the the generator and the shore plug to be electrically simultaneously connected. When that happens, unless miraculously the alternating current cycles from the two sources are perfectly aligned, I would expect you to hear expensive noises, see considerable smoke and to slap yourself up side the head. I cannot in good faith suggest damaging your coach and head in such fashion.
I have seen considerable ($$$$$$) damage done to oil field generator sets when 2 were feeding into each other because manual isolation switches were not properly configured. My advice is to take the time & effort to have it fixed right in the first place rather than having to take more time & $$$$$ to do it over.
(09-10-2016, 07:51 PM)Fulltiming Wrote: The auxiliary solenoids are a safety device to prevent connecting the shorepower and the generator together if a relay jams.
Yes, but then the fuse would blow and cut off the power.
Not necessarily, an example would be if the shorepower went down and you switched to generator power. At that point, your generator could be backfeeding the shorepower, a situation you never want to occur.
(09-11-2016, 10:16 AM)ccjohnson Wrote: I have seen considerable ($$$$$$) damage done to oil field generator sets when 2 were feeding into each other because manual isolation switches were not properly configured. My advice is to take the time & effort to have it fixed right in the first place rather than having to take more time & $$$$$ to do it over.
I'm not saying that is what I'm doing, I'm just curious about what these actually do. I took one apart and it's simply two pieces that make contact when electrified. So other than it essentially being another on/off switch for electricity to pass through to the adjacent contactor coil, I don't see it doing anything else. And how they can go bad is another question altogether.
But again, the switch inside only lets you choose shore, or generator, or neither, but never both. So if these only activate when the power is turned on at the switch above the driver and each contactor has a fuse to isolate them if stressed, then my simple mind asks, why the switch above the driver can't be connected directly to the corresponding contactor coil?
Now I'm the first to admit I'm not schooled in electrical workings, but that's why I ask questions.
I appreciate ALL the insight I am learning from this along with the very helpful advice from everyone on this forum: thank you.
If a main contactor gets stuck the interlock keeps the manual switch from causing simultaneous engagement on the opposing main contactor. It is not highly likely this will occur, but is worth preventing.
(09-10-2016, 07:51 PM)Fulltiming Wrote: The auxiliary solenoids are a safety device to prevent connecting the shorepower and the generator together if a relay jams.
Yes, but then the fuse would blow and cut off the power.
Not necessarily, an example would be if the shorepower went down and you switched to generator power. At that point, your generator could be backfeeding the shorepower, a situation you never want to occur.
(09-12-2016, 05:01 AM)77newell Wrote: If a main contactor gets stuck the interlock keeps the manual switch from causing simultaneous engagement on the opposing main contactor. It is not highly likely this will occur, but is worth preventing.
Thanks Jon. My example was based on an assumption, unfortunately an unstated assumption, that the main shorepower contactor stuck closed, such as from an overload welding the points together or the internal contactor springs breaking, but I didn't say that in the post so I really appreciate you clarifying my post.
