50 amp service only reading 30 amps on panel

Diver2diver · 08-06-2021, 10:06 PM

So I am out at a campsite and supposed to be plugged into 50 amp breaker. But on my control panel only getting 30 amp service lit up. So this mean I am getting one compressor running my basement air. If I run the generator then they both work. But when I shutdown the generator goes back to 30 amp lite and 1 compressor running. I have checked the connections on the ATS and they are all tight. Am I missing something? 2003 Journey DL.

cbeierl · 08-06-2021, 11:01 PM

If you are plugged into a 50A source and your EMS panel shows 30A the most likely cause is one of your 120V circuit breakers turned off. The EMS uses one L2 circuit to help it detect 50A service (typically the right-most breaker in your panel, but not always)--if that breaker is turned off the EMS won't be able to detect 50A service and will show 30A instead and will also drop loads to stay within 30A if possible.

deckape · 08-07-2021, 07:05 AM

Are you sure that you have 50amps,120v each leg, at the power pole? could be that the breaker is not getting both legs, as one pole is not connecting when you turned on breaker. Check with volt meter at 50amp outlet at pole. Reset breaker and check again. Just because you plugged into a 50, don't alway mean that you get 50.

Diver2diver · 08-07-2021, 07:14 AM

All the CB's are on. Unless I am in the work panel.

emiddleb · 08-07-2021, 07:17 AM

Your photo shows the washer/dryer 20amp breaker is off. Try turning it on.

Diver2diver · 08-07-2021, 07:20 AM

Its on now and it appears to be no change.

Diver2diver · 08-07-2021, 07:50 AM

This is the ATS panel

emiddleb · 08-07-2021, 08:00 AM

Well, you are at the point of getting out the meter and carefully checking your 120v legs. Or, if possible, try going to another site and see if the problem persists. The panel is relaying info from the circuit board that is inside your breaker panel. It doesn't see the 2nd leg, so that's what its showing. There is a 5amp fuse on the circuit board, but if that was blown your display would probably be dark. I'd work my way back, checking for 120v at the post, then at your Transfer switch, then at the breaker box itself. Needless to say, some care must be taken as you are dealing with 120v.

Another option, unlikely but easy to try, is to simply unplug from shore power for about 30 secs and then plug back in. Sometimes these systems get confused, just need to be reset.

Diver2diver · 08-07-2021, 10:31 AM

Ok so I have check for 120 volts at both CB's and I have good voltage thru out the box. So I guess maybe one of the capacitors may be weak and only starts off the generator? But does not explain why I cannot get a 50 amp light to come on..

cbeierl · 08-07-2021, 11:28 AM

Quote:

Originally Posted by Diver2diver

Ok so I have check for 120 volts at both CB's and I have good voltage thru out the box. So I guess maybe one of the capacitors may be weak and only starts off the generator? But does not explain why I cannot get a 50 amp light to come on..

If you measure between the two hot leads of your main feed into your breaker box you should either see 220V if you actually have 50A service (since the two legs should be 180deg out of phase) or 0V is you don't.

emiddleb · 08-07-2021, 11:36 AM

Quote:

Originally Posted by Diver2diver

Ok so I have check for 120 volts at both CB's and I have good voltage thru out the box. So I guess maybe one of the capacitors may be weak and only starts off the generator? But does not explain why I cannot get a 50 amp light to come on..

It's possible the itself board has an issue. Here's a thread with a similar problem and his solution... bad resistors on the board.

https://www.rvforum.net/threads/inte...roblems.81337/

Diver2diver · 08-07-2021, 01:28 PM

Ok so that was a good read on the board and that sounds promising. However I went back and checj a few more things and found that the 2 lines when measured across was 207 volts. With each leg at 120 volts. But the interesting part is with the generator running i only get 120 volts on both legs. And am not able to get 220 volts when I check for that. But the Air Conditioning works like normal on the generator and goes up to 28 AMPs which shows me both compressor are on. Is the EMS board out of the picture on the Generator?

emiddleb · 08-07-2021, 03:50 PM

Well, you are hitting the edge of my electrical knowledge, sorry. I know that shore power has 2 legs of 50 amp that are 180 out of phase, giving the 220 read. Pretty certain that the gen is kicking out two lines that are single phase. The EMS knows if the gen is running by a signal on a 12v wire going to pin 8. This turns on the Gen light on the display and the load display.

I think you've covered all the bases. Probably time to take a close look at the circuit board behind the breakers.

Diver2diver · 08-07-2021, 04:11 PM

Well I appreciate the info, I thing have covered all the bases with your help. And now I can talk with maybe someone at winnebago and think I know what I am talking about.

deckape · 08-07-2021, 05:54 PM

Are you getting 220 at the camp ground post. 120v each leg to ground ? Again might have to reset that 50 amp breaker.

Diver2diver · 08-07-2021, 07:22 PM

I have mentioned i do have 220 volts inside the MH at the CB. So it would be safe to say I have 220 volts at the post.

l1v3fr33ord1 · 08-07-2021, 08:32 PM

Diver2diver-

According to the wiring diagram (link here, sheet 2, zone C-2), the breaker second-from the left in the inverter sub-panel must be turned on in order for the EMS to correctly sense 50A. It looks as if the breaker is a 30A-15A combo. It's the 15A side that has to be on.

Diver2diver · 08-07-2021, 09:53 PM

Not sure wear you are seeing a open 15 amp breaker but the one for the Washer and dryer which is a 20 amp is closed and still have no 50 amp service.

cbeierl · 08-07-2021, 10:37 PM

Quote:

Originally Posted by Diver2diver

...However I went back and checj a few more things and found that the 2 lines when measured across was 207 volts. With each leg at 120 volts. ...

I'm not an expert at this, but my understanding is that 207V is approximately what you would expect to measure between any two of the 3 hot leads for 3-phase power source, since each leg is 120deg out of phase with the others. Is it possible that the 50A outlet is actually powered by 2 legs of a 3-phase power source?

l1v3fr33ord1 · 08-08-2021, 05:13 AM

Diver2diver-

I've extracted this from the wiring diagram and marked the breaker with a red arrow. The breaker is on the inverter subpanel, not the load center (i.e., the breaker panel with the washer/dryer breaker and whose picture you show on post #4).

According to the diagram, the EMS relay board gets its L1 and L2 signals from:

1) The water heater circuit breaker in the load center panel, and
2) The marked breaker in the inverter subpanel. It feeds a receptacle behind the refrigerator.

Both must be on for the EMS to work/display correctly.