Winnebago EMS not showing 50 amps

Vet Man · 08-23-2009, 07:23 PM

When plugged into 50 amp receptale the 30 amp light is lit on the EMS. Ems is shedding load as if I only have 30 amp. It is definitly pulled into 50 amp. Any ideas? Thanks

AFChap · 08-23-2009, 07:36 PM

Tell us more about your current situation.

The outlet may not be a REAL 50a outlet. If it has only one leg of 50a power, OR if both legs are from the same phase of the circuit, you DO NOT HAVE a true 50a connection. Unfortunately, too many "do it yourself" RV parks have improperly wired 50 amp outlets. If you have a multimeter, you can check the outlet. Across the two power legs, you should read 240v. If the outlet is improperly wired, you will read 120v.

Olive · 08-23-2009, 07:50 PM

I know of 2 couples who had the same thing happen to them in the last few months. One was on a 2006 Journey and the other was a 2006 Adventurer. In both cases the shedder board behind the PowerLine had gone bad. I think I was told the board was somewhere around $200, not sure if that was the installed price or just the board price.

Zimectrin · 08-23-2009, 09:33 PM

Did you do a search on this topic?

I think I remember several (5-6) years ago this problem came up and the fix was to remove "the wire" that plugs into the back of the EMS, count to ten, and plug it back in.(essentially a cold reset)

"The wire" looks like a R-22 telephone plug and is accessed by removing the screws(one on top, one on bottom) that hold the panel where the EMS and all that other good stuff is. It is in the back of the EMS modual.

Remember to do this on a night with a full moon after circling your unit three times. Seriously--Had to do this a couple of times myself. Easy to do and solved the hick-up.

Harry B · 08-23-2009, 11:46 PM

The problem might be as simple as a bad electrical box like Paul Indicated. There have been a lot of people that have had and are still having problems with the EMS control board, which was had an problem with under designed surface mount resistors.

Powerline now has a redesigned that board and no longer has the tiny surface mount resistors but now has regular 1 watt resistors. This will probably take care of the problem going forward. Take a look at this link http://www.irv2.com/forums/f101/ems-problem-5566-2.html. It should give you some idea as to what to look for.

I would however keep it simple and first try another electrical box from an other site.

Another thing to look for is to start the generator and see if the EMS panel indicates MG. If it does indicate MG instead of 30 Amp service, your problem is probably is not due to the EMS control board being defective.

AFChap · 08-24-2009, 02:04 PM

Quote:

start the generator and see if the EMS panel indicates MG

What does "MG" indicate -- I'm not familiar with that indication -- guess the newer EMS panels may be diffferent from mine.

Harry B · 08-24-2009, 02:33 PM

Quote:

Originally Posted by AFChap

What does "MG" indicate -- I'm not familiar with that indication -- guess the newer EMS panels may be diffferent from mine.

Hi Paul,

MG means motor generator. I went to look at exactly how my panel is labeled and what I needed to say was "Gen set".
Sorry about that. Well at least now your panel is up to date again Paul.

When the EMS panel has the burned up (or in some cases missing all together) resistors , it will not allow the panel to read anything other than 30 amp service.

AFChap · 08-24-2009, 03:01 PM

Quote:

MG means motor generator. I went to look at exactly how my panel is labeled and what I needed to say was "Gen set". Sorry about that. Well at least now your panel is up to date again Paul.

Thanks for the clarification. I was going to guess it might be "Main Generator" ... some new fangled designation to allow use of a second generator or whatever ...glad to know my panel is not obsolete!!

RustyJC · 08-24-2009, 03:12 PM

Quote:

Originally Posted by AFChap

Across the two power legs, you should read 240v. If the outlet is improperly wired, you will read 120v.

If it's improperly wired with the hot legs in phase, you'll read 0VAC from L1 to L2.

Rusty

Keith K · 08-25-2009, 11:07 AM

I have the same problem - it's definitely the EMS board. I talked to a tech at GNR, he thinks it's the circuit that recognizes 30vs50 Amp, if it stays open, it will treat all voltage as 30A. It's a bit of an annoyance, as it sheds appliances even when not necessary, but other than that it works fine. I'm told you can disconnect the board at the circuit breaker box which will mean your coach runs in a non-EMS mode. I'm just leaving mine alone for now, the occasional shedding of power isn't an issue. I'm not sure it's worth $200 bucks to me to correct the problem.

Harry B · 08-25-2009, 11:49 AM

Keith,

The problem is due to undersized resistors mounted on the smaller of the two circuit boards (36K ohm, 8 total, connected in pairs of two). One set of these monitors line two of the incoming electric. You'll be able to identify them by the blackened circuit board where they are mounted. These burn out because they are under sized for their application. I just replaced all eight of them with four 18K ohm 1 watt resistors and things are working again. However even the 1 watt resistors get pretty warm. I figured it's broken anyway, I'll try repairing it first.

This seems to be a recurring problem since 2004 through at least 2008. A few days ago I found out that Powerline has recently redesigned that board. They made the same change I had already made except that I have mounted them on a separate small circuit board and raised the resistors up to provide better cooling, since 1 watt resistors still run pretty warm. Cost was less than $4 to implement.

Vet Man · 08-25-2009, 01:34 PM

Thanks for all the reply's. We are at Alpine Lake RV Resort, in NY near Lake George. We had the EMS panel board replaced 2 weeks ago, so it is the reason for my concern. The girl at the desk here said all sites are 30 amp no matter if the breaker, and receptical says 50amp, there is also a 30 amp in the box. I guess I will have to wait until I get to another 50amp site. I have leaned alot from your posts, thanks.