AC power at half

Mountainbound · 07-24-2019, 04:38 PM

My electric is not functioning in our 2013 Alpine 3555 RL. I am reading just over 50 volts at the outlets. My 50 amp post is reading correctly, the LEDs on the surge protector is showing no problems. I did a continuity check on each wire of the shore line and it is good. I took the cover off the fuse panel and I see no loose or burnt wires and flipping the main 50 amp breakers does not change anything. Access to the backside of the panel is very hard behind the furnace and beyond the shower in the basement. Before I do anything more like tear off the underbelly or anything else I am wondering what this problem may be? For now I have everything disconnected including the battery. Anyone else ever had this problem?

Thank you

**sourdough** · 07-24-2019, 04:43 PM

The 50A ped is right? How do you know and how was it checked? LEDs on "surge protector" showing no problems? What kind of "surge protector" and how does a "surge protector" read all of the issues AC can have? Something doesn't sound right with the analysis to me unless you burned something up somewhere but you should be aware of that. Post the voltages per leg for the 50A ped. I don't think you will know if the neutral and ground are good......??

Mountainbound · 07-24-2019, 05:44 PM

Both legs are reading the full voltage on my VOLT meter at my 50 amp post. I can not remember the name of my surge protector at the moment. My next step may be to plug the unit back in and check the voltage at the panel but I am afraid of destroying the converter since only 54 volts is showing up at the outlets. Also I may try it without the surge protector but again I don't want to damage any circuit boards or anything.

**sourdough** · 07-24-2019, 05:56 PM

If you have 120vac on both hot legs at the ped and you don't in the RV it is probably the "surge protector". Your AC comes in on 2 separate legs, 120vac each - each leg feeds different things fed thru the power panel. It feeds the converter but the converter does not feed your AC outlets. For both legs to be at 50vac in the trailer, barring some weird failure of an appliance, your "surge protector" is more than likely the villain. Pull it off and plug in the trailer - if the ped power is OK you have no issues. If that works, post back...you need something far better than a "surge protector".

**JRTJH** · 07-24-2019, 06:04 PM

You can turn all the circuit breakers INSIDE your RV off and then check the voltage coming into the RV power center. Doing that (turning off the breakers) will protect everything inside your RV from "bad voltage" and allow you to check the input power through the surge protector and to the buss bar inside the power center. Each leg of the voltage (black wire and red wire) should have 120 VAC and be connected, one to each side of the circuit breaker buss bar. The white wire should be connected to the neutral bar and the ground should be physically connected to the ground bar/other "bare copper wires" (the actual location of the ground connection might vary from trailer to trailer, but should physically be connected to the ground system)...

If you don't have 120 VAC on each leg at the power center buss bar, then work back toward your surge protector, first the output side, then the input side, then the trailer wall 50 amp connector, then the shore power cord (where it connects to the trailer) then the power cord (where it connects to the campground power pole)...

ChuckS · 07-24-2019, 06:57 PM

If your not sure how to measure your incoming AC power at the power center inside this may help you. Or not... from my Alpine.

Lee · 07-25-2019, 06:05 AM

Quote:

Originally Posted by Mountainbound

I took the cover off the fuse panel and I see no loose or burnt wires and flipping the main 50 amp breakers does not change anything.

Thank you

Please clarify this statement...... Are you saying that even with the main 50A breakers off,... you still have 50v at the outlets?

Lee

Roscommon48 · 07-25-2019, 08:35 AM

i'd do a couple of things. 1. try another ele. outlet at campground. 2. try ele without the surge protector, to me they are just a pain when they are not working well.

and, if you aren't sure from there get an electrical and pay the fee, that is what rving is all about--spend money.

ChuckS · 07-25-2019, 12:20 PM

Well OP did you resolve the issue ?

travelin texans · 07-25-2019, 12:50 PM

Quote:

Originally Posted by Roscommon48

i'd do a couple of things. 1. try another ele. outlet at campground. 2. try ele without the surge protector, to me they are just a pain when they are not working well.

and, if you aren't sure from there get an electrical and pay the fee, that is what rving is all about--spend money.

There's usually a reason if they aren't working well, either the pedestal or the RV has problems. I'd try a different pedestal rather than bypassing the EMS, hopefully not just a surge protector, & risk further damage.
If it's a PI brand & found to be the problem they are warrantied, contact them for a replacement.

Mountainbound · 07-25-2019, 04:31 PM

Thank you for all the input. My RV is at my home where I keep it connected to a 50 AMP pedestal. I again checked the pedestal and then plugged just the surge protector in and tested the voltage on it and its reading 119 to 120 on each leg. Turning off all the breakers is a great idea before I proceed with anything else. I am also going to clean all the blades on the shore cord and also where the power goes in but I will have to tackle this on the weekend due to my work hours. I ran a continuity check on the shore cord but I am going to see if I can borrow a friend of mine cord just to be sure there is not a problem with mine.

Mountainbound · 07-25-2019, 04:40 PM

Thank you ChuckS for the PDF. Huge help. Lee, there is no power at all with the breakers off, just half voltage with them on. Sorry for any mix up on that.

**sourdough** · 07-25-2019, 07:15 PM

Are we dealing with a "surge protector" with some LEDs that tell you something but don't protect you or a true "EMS" that shows what's happening electrically and shuts down the power? The newer ones monitor incoming power AND what's happening in the trailer to protect you. The others, like mine, protect you from any issues coming in. To have 50vac on every electrical outlet/appliance with proper voltage coming in should be pretty easy to isolate I would think.

bobbecky · 07-25-2019, 09:14 PM

Half voltage with breakers turned on, but measuring 120 volts could very well be an open neutral. With the shore cord hooked up at the pedestal but disconnected from the trailer, you should be able to test voltage at the trailer end of the shore cord to prove it good or bad. If good, then you need to make sure the socket that the shore cord plugs into is connected, and this means pulling out the entire socket and checking that all the wires that go to the rig's panel are solidly connected. If all these checks are good, check voltage at the 50 amp two pole breaker in the rig with the breaker open at the point where the wires are connected. If voltage is good there, and you close the breaker but get bad voltage at the bus bars that the sub breakers are plugged into, then maybe you have a failed main breaker.

Mountainbound · 07-28-2019, 06:02 PM

I found the culprit. I decided to replace the molded plug on the 50 amp cord. The inside may have melted or pulled lose even tough it checked out alright when I did a continuity check. The circuit box is now reading correctly but as I turned on each breaker the clock on the microwave did not come on. I checked that outlet and it read 110 volts, pugged in the microwave and the turntable was turning very slowly with the door open. Very weird so I guess the board is fried in it. I had to work Saturday so today was the first time I have had to try to fix things. Everything else seems to be working now but I have unplugged the RV for the night until I can get everything back in place. Thank you to everyone for their input on this.

**sourdough** · 07-28-2019, 06:36 PM

I didn't see where you posted what you have as a "surge protector". I'm afraid that is what you have and it provides minimal protection. For the molded end of the 50A plug to "melt" would indicate, to me, that you either have faulty breakers in the trailer (I doubt) or lack of protection from the incoming/feed side. EMS is the only way to go and I'm afraid you may be finding that out with a fried microwave...thankfully it wasn't the fridge.

bobbecky · 07-28-2019, 08:40 PM

Anything on the source side of a breaker, whether it is a sub-breaker or the main breaker will not affect the breaker. A fault between the main breaker of the rig and the breaker in the pedestal should have tripped the pedestal breaker. An EMS or surge arrester plugged in to the pedestal will only protect an issue from the outlet of the pedestal back into the park's electrical system. A hardwired EMS just before the RV main panel will protect against a fault from the EMS all the way back into the park's system, and that includes a faulted shore cable.

ChuckS · 07-29-2019, 05:44 AM

Quote:

Originally Posted by bobbecky

Anything on the source side of a breaker, whether it is a sub-breaker or the main breaker will not affect the breaker. A fault between the main breaker of the rig and the breaker in the pedestal should have tripped the pedestal breaker. An EMS or surge arrester plugged in to the pedestal will only protect an issue from the outlet of the pedestal back into the park's electrical system. A hardwired EMS just before the RV main panel will protect against a fault from the EMS all the way back into the park's system, and that includes a faulted shore cable.

What your saying doesn’t make sense to me. An EMS protects items PAST its hookup point at the park pedestal. If it only protected the parks power why the heck would I want one. A plug in one will work just as good as a had wired one in most cases.

http://https://www.progressiveindustries.net/ems-pt-x

ChuckS · 07-29-2019, 05:49 AM

And I’d also be verifying the converter didn’t get fried as well. It is on all the time so the second you had issue the converter most likely took a hit as well. Verifying converter by measuring DC output

travelin texans · 07-29-2019, 08:13 AM

Quote:

Originally Posted by ChuckS

What your saying doesn’t make sense to me. An EMS protects items PAST its hookup point at the park pedestal. If it only protected the parks power why the heck would I want one. A plug in one will work just as good as a had wired one in most cases.

http://https://www.progressiveindustries.net/ems-pt-x

I totally agree! I've used the portable since '05 & has saved our rig several times I know of & who knows how many I don't.
If by chance you have a problem with your shore cord between the EMS & the RV then no it won't help.

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