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bobk3d · 04-02-2017, 04:18 PM

My shore power started cutting out briefly a few weeks ago. It would always come back in 2-4 minutes. Then it worked fine for a week, then it got worse, and today, it's pretty much off. Works fine on generator, though.

Coach is a 2003 Bounder gas, 30 amp. Pretty simple system.

I do have a Progressive surge device, and that was obviously the first thing to check, but I'm pretty sure I can rule that out. Campground power is good, and this has happened at three different campsites. Seems to be voltage at the output.

I was confused because a non-contact meter shows voltage at all of the breakers in the main box, but none in the coach. Then I realized I was only checking one lead at the breaker. Perhaps the transfer switch isn't connecting the neutral properly. Would that explain it?

jelag · 04-02-2017, 05:01 PM

so your surge protector is most likely a 1 to 1 wound transformer.... so the input and the output of a transformer are not connected electrically.... but its the magnetic field in one that makes voltage and current in the second winding... so the only way to test your surge protector is with a mechanical voltmeter... either a mechanical meter or digital volt meter.... that would be my first test.... or if this just plugs in... take it out of the circuit and than see what works....

If your power cord plugs into the coach like mine does... you can disconnect it from the coach and use the voltmeter to check if there is voltage on both legs of your cord... one leg to neutral should read about 120 VAC. if you find that there is power across the connector at the end of the cord... re-connect it back to the coach and than trace that back to the power (breaker box) and see if there is voltage at the main on the breaker box....

If any of the above is beyond your ability to understand what I've written do not attempt this.... as there is a shock hazard at the tips of the volt meter if its used incorrectly and you touch it....

BTW the power cord should be a 3 prong cord.. the center middle prong is the ground, one of the other blades is the neutral and the last blade is the 120 VAC.

Boyd R · 04-02-2017, 05:11 PM

Does your coach have a inverter ?

I had a similar issue a few months ago, and it wound up being the cable between the remote (control inside coach) and the inverter.
I would loose 110 on a few circuits, then it would come back on in a matter of minutes. Never kicked a breaker or a gfi.

bobk3d · 04-02-2017, 05:28 PM

Thanks.

I only checked the output of the surge protector with a non-contact meter, so it's possible that only one leg is active. But I'm not sure I want to measure it hot, the connections could short pretty easily once I unwrap them, and it's not an easy spot to reach. It's wired in, but it's fairly easy to rewire to bypass it; at least I'd be working on cold wires.

I'm still betting on the transfer switch, but I should probably rule out the surge first, since the transfer switch isn't easy to get to.

Fleetwood's wiring isn't going to win any awards for neatness, BTW.

Quote:

Originally Posted by jelag

so your surge protector is most likely a 1 to 1 wound transformer.... so the input and the output of a transformer are not connected electrically.... but its the magnetic field in one that makes voltage and current in the second winding... so the only way to test your surge protector is with a mechanical voltmeter... either a mechanical meter or digital volt meter.... that would be my first test.... or if this just plugs in... take it out of the circuit and than see what works....

bobk3d · 04-02-2017, 05:30 PM

Nope, no built-in inverter.

Quote:

Originally Posted by Boyd R

Does your coach have a inverter ?

jelag · 04-02-2017, 05:33 PM

If you are dealing with a 30 amp circuit you only have ONE LEG... if you have a 50 amp circuit you have (2) legs of 120VAC. and your proximity tester is looking for a magnetic field and than lighting from that magnetic field... so your surge protector will have at least one transformer (READ MAGNETIC FIELD) but that doesn't mean it has output... put your proximity tester after the surge protestor on the way to the breaker panel and see if it lights.... geez... I personally hate those things... it means it's hot.. but doesn't give you any idea what the voltage is... or if it functions....

bobk3d · 04-02-2017, 05:45 PM

Well, one "leg" probably wasn't the right term. But if the hot is connected and the neutral is not, wouldn't that leave the outlets dead?

I did check about 3 feet downstream from the surge, but couldn't get decent readings on the individual leads, so that's why it's inconclusive.

Also checked at the breaker box. The non-contact meter shows voltage at the input of the breaker, but I assume that's just the hot lead, and that's all I can access. If I shut off the main, the other breakers go dead, like they should. So voltage is getting to the breaker box, at least on the hot lead, right? I can probably test that safely with a contact meter, so that'll be the next step, along with removing the surge protector from the circuit.

I suppose it would be safer if I tested it using a 20-amp circuit with a GFCI.

Quote:

Originally Posted by jelag

put your proximity tester after the surge protestor on the way to the breaker panel and see if it lights.... geez... I personally hate those things... it means it's hot.. but doesn't give you any idea what the voltage is... or if it functions....

Pusherman · 04-02-2017, 05:52 PM

Sounds to me like a bad transfer switch between shore power and the generator.

Here's the evidence: Works OK on generator, but intermittent on shore power.

The generator has preference between these two; that means the relays hold open for shore power, but closed for generator. It's working in the closed position, but intermittently in the open position on shore power.

I'd definitely be looking at the transfer switch.

gemert · 04-02-2017, 06:47 PM

From what you posted it sounds like the transfer switch. Easy check, just check the output of the TS while on shore power.

SpringerPop · 04-02-2017, 06:58 PM

What, if any, error codes does your Progressive EMS read? If it reads E-0, does it have any P codes?

Also, remember that the Progressive has a contactor inside, too, that might be getting intermittent.

Pop

Sweetbriar · 04-02-2017, 07:08 PM

What I would do - unplug from shore and trip the circuit breaker on the generator (safety is paramount). Tighten every screw, terminal and wire hold down starting at the shore power plug thru the transfer switch and AC breaker panel. Back the hold down off a half a turn, wiggle the conductor then tighten back down. Then I would find one of my Navigator's disposable nail files and clean up all the relay contacts of the transfer switch. Probably don't need to do the breaker panel considering the generator power is OK but it's still a good check to perform. Same for the transfer switch shore power contacts. If after all that power was still dropping intermittently I would bypass the EMS and see what happens.

Be careful with the non-contact power sensor. I really like them for basic checks looking for an open circuit and such but it's not a one for one replacement for a meter. Your problem could be as simple as bit of corrosion inside the shore power cable end that is causing a drop in volts but just enough the EMS is happy until a camper three sites down fires up the microwave and the volts drop enough that the EMS trips for low volts.

bobk3d · 04-02-2017, 09:11 PM

Thanks all.

Based on the odds, I'm guessing it's far more likely to be the 14 year old transfer switch than the months-old surge protector.

I'm pretty certain I can rule out voltage drops and all that, and went through it with Progressive tech, and it shows no errors, no bad voltage, doesn't act like it would if it had an error. I've all but verified that it's passing power when the coach power is out.

Unfortunately, I can't easily access the transfer switch to measure it, it's behind the breakers.

If the transfer switch is bad, I have a service plan that will pay somebody else to replace it, so I'm trying to narrow the problem down without actually pulling the breaker box myself. I tend to troubleshoot very slowly and methodically.

I'll go through as much as I can with a real voltmeter tomorrow, but I suspect the results will all be the same.

gemert · 04-02-2017, 10:24 PM

Quote:

Originally Posted by bobk3d

Thanks all.

Based on the odds, I'm guessing it's far more likely to be the 14 year old transfer switch than the months-old surge protector.

I'm pretty certain I can rule out voltage drops and all that, and went through it with Progressive tech, and it shows no errors, no bad voltage, doesn't act like it would if it had an error. I've all but verified that it's passing power when the coach power is out.

Unfortunately, I can't easily access the transfer switch to measure it, it's behind the breakers.

If the transfer switch is bad, I have a service plan that will pay somebody else to replace it, so I'm trying to narrow the problem down without actually pulling the breaker box myself. I tend to troubleshoot very slowly and methodically.

I'll go through as much as I can with a real voltmeter tomorrow, but I suspect the results will all be the same.

One more thing in support of the TS being bad. TS's default to the generator. So if it isn't functioning it will most likely allow genny power to pass and not shore power. That is not absolute but close. It needs a relay to switch under shore power to switch over to shore power. Likely that relay is not functioning. Just a possibility.