Only one leg of 50amp working (until)

raptor0818 · 04-23-2023, 01:16 PM

Afternoon everyone, got to a new site this morning and plugged in to a 50 amp service. Green light on the EMS and thought I was all set for power , got in the RV and only had one air conditioner working. No microwave, tv, and some outlets. Checked circuit breakers, reset circuit breakers and still nothing. Went to the power pedestal and shut off breaker, disconnected power cord and started from scratch, went back into rv and everything was working. Wondering if this was fluke or the start of something? Looking forward to all your comments and advice.

2021 Alpine 3850RD
2019 Ram 3500

**chuckster57** · 04-23-2023, 01:23 PM

May have been an anomaly, I would watch it.

notanlines · 04-23-2023, 01:25 PM

Maybe just as a precaution pull your plug and wirebrush the four prongs on the end.

**JRTJH** · 04-23-2023, 01:56 PM

You've got a 2021 power cord, trailer circuit breaker box and I'd guess a relatively new EMS.... That campground power pedestal is "who knows how old or in what condition or how much abuse it's received over the years"....

I'd "err on the side of caution" and keep an eye on the EMS and your power center, but I'd suspect that when you turned the campground circuit breaker off and then plugged in and turned it back on, it may not have made good contact inside the circuit breaker.... After hundreds, maybe thousands of times being turned on and off, the springs in a circuit breaker can get weak and just not always "travel the full distance from open contacts to closed contacts"... Then add arcing and sparking that causes contact pitting and who knows if that campground circuit breaker is "always going to be functional"....

I'd suspect the campground, but watch the trailer carefully for a few days to see if any repeats or other issues arise.....

bobbecky · 04-23-2023, 02:41 PM

This is the kind of event that calls for a basic voltmeter. If your EMS is the portable type, it is looking at the power it is plugged into, and if it said power was good, it probably was. What the EMS can't see is your shore cord connections or anything else that is plugged in to it. I would be double checking the shore cord at both ends and also the receptacle on the trailer that the cord plugs into, even remove that receptacle to make sure the screw connections are all tight. Another location that can have loose connections is in the trailer panel, so checking all the connections, even the 12 volt connections while you are at it. Just do all this checking and tightening when the shore cord is disconnected. If you are careful, the 12 volt connections can be done energized.

rhagfo · 04-23-2023, 07:10 PM

Quote:

Originally Posted by JRTJH

You've got a 2021 power cord, trailer circuit breaker box and I'd guess a relatively new EMS.... That campground power pedestal is "who knows how old or in what condition or how much abuse it's received over the years"....

I'd "err on the side of caution" and keep an eye on the EMS and your power center, but I'd suspect that when you turned the campground circuit breaker off and then plugged in and turned it back on, it may not have made good contact inside the circuit breaker.... After hundreds, maybe thousands of times being turned on and off, the springs in a circuit breaker can get weak and just not always "travel the full distance from open contacts to closed contacts"... Then add arcing and sparking that causes contact pitting and who knows if that campground circuit breaker is "always going to be functional"....

I'd suspect the campground, but watch the trailer carefully for a few days to see if any repeats or other issues arise.....

Suprised the EMS didn’t shut down if no voltage on one leg.

CedarCreekWoody · 04-24-2023, 05:01 AM

Quote:

Originally Posted by rhagfo

Suprised the EMS didn’t shut down if no voltage on one leg.

Some EMS units don't have automatic shut off when they detect a problem. It is best when they do have that feature.

wiredgeorge · 04-24-2023, 05:09 AM

Quote:

Originally Posted by raptor0818

Afternoon everyone, got to a new site this morning and plugged in to a 50 amp service. Green light on the EMS and thought I was all set for power , got in the RV and only had one air conditioner working. No microwave, tv, and some outlets. Checked circuit breakers, reset circuit breakers and still nothing. Went to the power pedestal and shut off breaker, disconnected power cord and started from scratch, went back into rv and everything was working. Wondering if this was fluke or the start of something? Looking forward to all your comments and advice.

2021 Alpine 3850RD
2019 Ram 3500

You failed to mention brand/model of EMS. That would be helpful.

**JRTJH** · 04-24-2023, 09:45 AM

I got my "clues" from his first post. He said he plugged in, the EMS had a green light, so he went into the trailer and one leg was missing. He then went outside, turned off the campground circuit breaker, unplugged the trailer, plugged it back in, turned on the campground circuit breaker and went back inside to find everything was working....

So, the "clue" was that he functioned the campground circuit breaker, unplugged the trailer and plugged it back in....

Nothing changed INSIDE the trailer or, apparently in the EMS or the shore power cord, BUT the campground pedestal plug and circuit breaker were reseated....

Possible causes (at least in my mind) are the campground circuit breaker and/or the worn plug on the pedestal.... Reseating the plug may have "fixed it" or functioning the campground circuit breaker might have "fixed it"... My money is on the "likelyhood of worn out circuit breakers and corroded/loose plug fittings on the campground equipment, not on the OP's trailer or his equipment.....

As for the type of EMS, sounds like a "surge protector" rather than a true EMS.... A surge protector will "identify a problem" but leave the trailer connected and "watch it burn to the ground" while the red light blinks a warning..... That's why I dislike a surge protector and always advise to get a "true EMS" that will interrupt any damaging condition before it gets to the trailer.....

**sourdough** · 04-24-2023, 11:19 AM

This thread brings up a lot of little things we encounter at a park ped. Like most folks I imagine, I've seen receptacles in all kinds of conditions; melted, blackened, loose, wore out, metal innards sticking out...you name it. In some cases you just have to move, some cases you make do. A meter is your friend in a situation described by the OP. Another thing that I carry and use everywhere is what I term a "sacrificial" 18" extension so that those faulty receptacles can eat on the prongs all day long then when the end of my extension gets ratty looking just chunk it and get another one...beats the heck out of eating up the end of your EMS cable or trailer power cable. JMO

https://www.amazon.com/Camco-55215-1...7&sr=8-52&th=1

jimmyg · 04-30-2023, 07:59 AM

Had a similar issue. Just certain plugs, especially GFS plugs out. After attempts to figure it out, turned out it was the plug end of the power cord. Only one pole was working. Got this when it was suggested I buy a new power cord and if that wasn't the problem just return it. Unless you can borrow one from someone. I had the original cord repaired, then returned the new cord.

Gunny Mike · 04-30-2023, 09:32 AM

Just got our Outback from the service center for the same thing. They didn’t replace anything but indicated different power at the pedestal. They indicated to move to a different spot and should reset itself. Not the answer I wanted to hear but it’s working now.

Packed2Go · 04-30-2023, 09:40 AM

Two years ago I had the same issue. My hardwired EMS indicated all was well but I was missing a leg. Turned out the campground pedestal breaker was bad....was only providing current through one leg.

**sourdough** · 04-30-2023, 12:40 PM

I have not encountered a ped with one leg of the 50A missing with this EMS (Surge Guard). I do however look at it every time it comes on to check the voltage on each leg.

I'm thinking if it wasn't on one leg the only way I would know is by looking at the readout. There's nothing there to harm the RV, things just aren't going to work. I didn't pull the specs on it but I'm sure I'm right. I did pull the manual on the Progressive EMS-PT50X portable and it indicates it does not provide any "protect" mode for a missing leg of power. In that case the EMS probably does look "OK" but is missing the power on one leg. I'm sure that would hold true for both portable and hard wired units. Page 3 -

https://www.progressiveindustries.ne...4eb873cf39.pdf

Philip · 05-01-2023, 08:35 AM

Yes, we had this a couple years ago at a state park in Ohio. Frig was one of the things not working. Temps were moderate so we didn't need much power. We plugged the refrigerator directly into the pedestal next to us. All was good. Let host know the next day about the problem.

wiredgeorge · 05-01-2023, 08:45 AM

OP logged off 6 minutes after posting and hasn't replied to any of the points raised. Hope he gets things sort. Post was 4/23.

raptor0818 · 05-01-2023, 12:25 PM

Good Afternoon All, first I thank you for all your advice and comments and as usual, it was great advice. The reason I have not posted and commented was because we were still at the same CG and want to wait until we moved. Just got to Gateway to the Smokies in Pigeon Forge and as soon as I plugged we had/have all the power we needed. As stated in a post, I waited to check things out at another campground and now I assume it was the circuit breaker at the last campground. Things may not go right, but for me, this website surely makes things always manageable and correctable. Thank you

2019 Ram 3500
2021 Alpine 3850 RD

wiredgeorge · 05-01-2023, 01:37 PM

Quote:

Originally Posted by raptor0818

Good Afternoon All, first I thank you for all your advice and comments and as usual, it was great advice. The reason I have not posted and commented was because we were still at the same CG and want to wait until we moved. Just got to Gateway to the Smokies in Pigeon Forge and as soon as I plugged we had/have all the power we needed. As stated in a post, I waited to check things out at another campground and now I assume it was the circuit breaker at the last campground. Things may not go right, but for me, this website surely makes things always manageable and correctable. Thank you

2019 Ram 3500
2021 Alpine 3850 RD

Glad to hear your issue has resolved. What type EMS do you have?

raptor0818 · 05-01-2023, 03:53 PM

It is a Surge Guard by Rv Power Protection, Model 34750. You know it never ends. Was just checking out my furnace, while sleeping last night the furnace started making a surging sound. Wish I could make the same sound while writing, but I can't. It just doesn't sound right and hoping it's minor and I can still use it a few more days. We were on I-40 and I-26 from Florida to Pigeon Forge and they both beat the Sh_t out of us.

2019 Ram 3500
2021 Alpine 3850 rd
Berkley, Ma

LHaven · 05-02-2023, 03:31 AM

Well, that explains why it showed green. It isn't an EMS, it's just a surge protector. A real EMS would have alarmed.

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