Community Forums

4marc · 03-17-2009, 07:38 PM

Hello all - I'm a new forum member. I just bought a 2000 Newmar Mountain Aire MADP 4093.

I (and the others in my RV park) am unable to get the shore power (50A) working. Here are the facts:
- other RVs work fine on the shore-power posts
- the MADP does not work on any of the same posts
- i tested the posts with a multimeter:
--- left-to-neutral = 120v
--- right-to-neutral = 120v
--- left-to-right = 240v
--- i'm assuming this is ok
- the shore power cable goes into a clear plexiglass box
--- labelled AECS ESP 10045 (by automated engineering corp)
--- the only status light lit says "wire fault"
--- a green digital LED readout says "nEU"
--- all the indicators everywhere on the MADP (on the xantrex, on the remote monitoring panel over the door, etc) all report no AC current

:-(

Any ideas?

........................................
marc

Mountain Aire III · 03-17-2009, 07:46 PM

I had a similar problem recently. Have you tried plugging into just 30 amp? If it receives power fine the problem is most likely the circuit breaker on the post itself. Those breakers springs get weak after time and don't fully turn on thus only outputting some power. Good Luck

"007" · 03-17-2009, 08:31 PM

Welcome 4marc to the Newmar forum and irv2.

Sounds like the park has a neutral ground problem. Not sure how much 50 amp cord you have to find a good pedestal but I would ask for an other site. Does your coach have a surge protector? Its a good idea to have one and if you do have one its doing its job by not allowing what ever is wrong not to do damage to the items off you load center in coach.
Having others in park with same problem would make it the parks problem I would say. :(
I had something similar and my SP would trip off power in the middle of the night was a neutral problem.
Congrats on your new coach enjoy and safe travels.

4marc · 03-17-2009, 09:13 PM

007 and MAIII, thanks for the advice. I count myself fortunate to have found you guys, and this forum.

To my knowledge, the other park guests have OK 50A power. I will ask my neigbors if i can try swapping my cable with theirs on their post, to see if it works. I tried two other unoccupied posts, with the same error code. Just in case it was something INSIDE the MADP, i also tried reconnecting after unplugging everything i could find that was 120VAC - the microwave, the AC breakers in the bedroom (including the ones for the roof ACs, the fridge, the splendide washer, and the TV). Still no dice.

.....................................
marc

RVDude · 03-17-2009, 10:18 PM

Your AECS is an “”Automated Electrical Control System “AECS with ESP” (Electrical System Protection)”” system hardwired into your coach. Google "aecs esp" and you'll get some old links but I could not find the manual for you – try Googling a little more and you might come up with it.

Like 007 said, it is designed to protect your rig from an improperly wired electrical supply by shutting off the power before it enters your rig. Such devices (commonly called in forums a surge protector or some folks will even stretch and call it an EMS) typically protect from high/low voltage and improper grounds and/or neutral wiring. Any of which can damage sensitive electronics, air conditioners, or even the entire rig’s electrical system. Such faults can even cause a shock between your feet on the ground and your hand on a metal handle. Yes, a coach without one might work fine but they could be at risk. Be glad you have such a system.

The "neu" and "wire fault" your system is showing sure sounds like it is sensing a bad neutral in the pedestal. The voltage you measured - a great first step - across L1-N, L2-N and L1-L2 voltages will not tell you there is a bad, weak, or even a reversed N or G but the AECS will sense such troubles. Your appliances will thank you as will the elimination of potential shock hazards. Typically these pedestal faults are isolated to a few pedestals in a park, but the faults can be park wide. Just move sites or have them fix the pedestal problem. See if any of your neighbors are running a "surge protector" like SurgeGuard or Progressive Industries.

It is possible that your AECS might be malfunctioning too. Only way to tell is to test the pedestal. Someone in the park might even have a tester you could borrow, I would hope the CG maintenance folks would have one you might use too.

There might be a bypass switch on your AECS unit but borrow a portable surge guard before plugging in your bypassed plug. If your unit is defective, an electrician can simply bypass it and you can buy a portable surge protector from the two brands I mentioned. Or replace your unit with another hardwired one.

4marc · 03-18-2009, 06:00 PM

RVDude - i am searching for AECS ESP - like you said, not much info. I sent an email to the listed contact at teamaec.com, but he replied today, and said I had the wrong AEC (company).

Let me share with you guys my additional checks. As we know, the AECS box says nEU on the green readout, and the "WIRE FAULT" light is lit.

1) i opened the AECS box to put my multimeter prongs on the terminal screws, on the incoming power side, and on the outgoing power side.
2) continuity between AECS incoming terminal screws and RV shore cable male prongs is zero (ok) for all four prongs
3) when power gets switched on (using the breaker on the park's pedestal) the LCD readout says P95 first, then changes to nEU (with a slight flicker).
4) there is zero voltage on the outgoing power terminal screws, across L1-neutral or L2-neutral. So the power really does stop at the AECS box.
5) Same condition when trying each of the three park pedestals reachable by my cable. I haven't tried my neighbors yet - they're not in their rig and i don't want to unplug them.
6) ... back to the google :-)

4marc · 03-18-2009, 06:16 PM

When you google "aecs esp neu", the top link is this tantalizing entry:

OPERATORS MANUAL

- 2 visits - 8:08pmAutomated Electrical Control System “AECS with ESP” (Electrical System Protection) .... nEu. Open Neutral. PoL. Reverse Polarity ...
www.shockshield.com/aec/pu049-new.pdf - Similar pages -
by IS INSTRUCTIONS - Related articles - All 45 versions

So - the code means "open neutral," like RVdude said. This PDF is gone though. I'm going to try to contact ShockShield to get a copy.

Latitude · 03-18-2009, 06:52 PM

Marc

As RV Dude has said your AECS is detecting anopen neutral, at that post can you get to a post that another Rig is using, with a Surge Protector, and is getting a good power source, This should tell you if it is your AECS that might be malfunctioning, and then you could see if you could bypass the AECS.

Rick