I've had recurring issues plugging into shore power for the last several months. Today, I dug in further and I'm seeing error codes displayed on my surge protector. U01, C09, and d.1
Background:
I'm parking at a covered storage facility, plugged into a shared 20A circuit. It's usually just me and one other trailer, and I don't think he's moved it in the last 9 months (so I'm the only one actively doing anything). In the past, there were multiple cases where the GFCI was tripped. I worked with another member here and I think we got it nailed down to disabling the inverter while on shore - something about unbonded grounds? I forget. But I keep my Xantrex SW3012 set to 5A. It seemed to work for a little bit but I still check on it every few days - sometimes it's tripped, other times it's fine. So I'm not sure if it's me or maybe the other guy has something pulling a heavy load.
Today I went and checked on it - the circuit was not tripped, but the batteries were not being charged.
Here's what I see - if I start by plugging in shore power, I get the ~2 min delay and the surge protector panel in my utility bay lights up. It displays U01 C09 U01 C09 d.1
I can't find any documentation on the U01 and C09 error codes. I believe the d.1 is as described on the sticker on the enclosure. It says to press bypass and retest. If I go to the panel inside and hit bypass, the GFCI trips.
What's weird is that when parked at a campground with 50A service, it seems to do fine. I seem to recall that I had to bypass last time to get the shore power into the inverter/charger, but we were good for the duration.
I need to go back and repeat all of this on generator power - I would expect similar results unless the problem somehow stems from the circuit I'm plugged into.
I've attached a pic of the error code sticker. d.1 says WELDED CONTACTOR OR INVERTER FEEDBACK (PRESS BY-PASS SWITCH TO REST & RETEST FAULT). There is nothing listed for U01 or C09. I also show a pic of the interior display that has the bypass button.
Last - I have a pic of the ESP display when things are operating normally. Notice the display says 8.8.8. with both the FAULT and DELAY lights lit up. The Xantrex display shows AC charge light on with data for the AC coming in. It was like that during our walk thru as well, I'm just now trying to understand it.
Is there anything that jumps out?
I haven't been able to find any markings on the surge protector to find brand/model info yet, and haven't been able to find anything in the forums on these error codes. It seems that surge protectors were standard starting in 2003.
I would begin by looking for the cross connection between the ground and neutral. Both the inverter and the generator transfer switch relays have contacts that separate the ground and neutral when connected to shore power. When on Generator the transfer switch ties the two together. Same for the inverter. Both relays should never be on at the same time. When plugged in both those relays need to off and the ground-neutral separated. If not, you will trip the GFCI feeding the coach.
2003 used an Intermatic which just had a couple of lights on it, not the brand you have.
That is probably from Automated Engineering Corp. / AC Transfer Switch "AECS with ESP" / 10040A
That company is long out of business.
I recall they were purchased by TRC (Surge Guard) so you can try contacting them to see if they have any documentation for those unlisted codes. They also had, at one time, a plugin replacement unit which if still available maybe something to consider.
I'm leaning toward just replacing it with a new automatic transfer switch, but without surge/line protection.
- As mentioned, AEC is out of business. From what I've read, Surge Guard doesn't seem to want to support these old units.
- I currently use a Progressive Industries for shore surge protector already, no need to continue to double up on protection
- Surge Guard wants about $1k to replace what I have (ATS + inside display). I can get a Furrion F50-ATS or Progressive PD52V for about $200
- Someone had their rebuilt - but I don't want to wait to send it off somewhere and likely pay more than I will for a replacement unit that I can have in hand this week.
I need to see what kind of slack there is in the cables for generator and shore coming in and line coming out. Then I'll decide between the 2. The ATS I have now has generator and shore coming in from the left and line out coming out the right side.
- The Progressive can't be mounted horizontally - they want the relays to be vertical.
- Furrion doesn't have that limitation but the sticker on the front shows the inputs coming from the right (instead of the left as current). Purely cosmetic though.
The Nimbus only has the one transfer switch. Line out goes to the 50A panel, then circuit 8 goes to the inverter. I know some of the older ones had another transfer switch after the 50A panel. So replacing this one would mean that I'm done.