CMP 10 AC Reading

[Jeremy Parrett]

After the problems with an open neutral on the pedestal box my CMP is now telling me I have AC  120 Volts on leg one  drawing 17 amps with a/c running.
  It also tells me I have NO AC voltage on AC Leg 2  but drawing 13 amps with a/c running . 
    How can this be?  Is it possible the electrician missed a connection ? 
  Where does the CMP read this voltage from?

[Fred Brooks]

       Jeremy, If both air conditioners are operational, you both legs of 120 volts coming into the main circuit breaker box in the closet. You can confirm this with a multi meter reading between the RED wire and the neutral white wire and the BLACK wire and the neutral wire.
        Here is the bad news, any time a coach looses a neutral wire at the pedestal, it can cause all sorts of collateral damage. You need to check EVERYTHING in the coach that is 120 volts and has a PC Board intergrated in it. Example would be TVs, Microwave, DVD players, air conditioners, converter/inverter, all electronics such as your CMP and Silverleaf. Try and find a RVIA certified technician and perform a comprehensive electrical check so you have no skeletons in the closet. Call me at 520 309 1260 if you have further questions. Fred Brooks

[Edward Buker]

Jeremy,

In the box next to the transfer switch (same size grey box) are the AC voltage and current pickups for the CMP panel. The round toroidal transformer pick up winding gets a current induced that is translated to current on the panel which seem to be fine. There is also two small 10:1 wound transformers numbered 241-3-12. There is 120V on one side (input) and there should be 12V (step down output) on the other side. Check for the 12V output which goes to the panel. There may be a fuse involved that is blown if you get lucky. I seem to recall a buss type fuse. If there is 120V coming into the transformer but no voltage coming out the output winding you can look up this transformer number online, last I looked it was available. Hope this helps. Like both Fred and I and others have said, check everything electrical.

Later Ed

[Jerry Emert]

Jeremy, when my storage lot mis-wired the electrical box for my coach I lost the inverter, a DVD and the front AC (after a few months.)  And in response to your issue, two relays and two bus fuses in the Aladdin junction box.  The relays were what Ed described as indicating line voltage to the Aladdin.  Once the fuses were replaced I had to replace the relays and all readings were normal.  Good luck.
Jerry

[Jeremy Parrett]

Fred,Ed and Gerry,
  Ok...thanks for the advice .  I will locate this relay box and check it out.   

[Edward Buker]

Jerry,

The relays and circuit board for the transfer switch is in one of the grey boxes and next to it is the box with the pickups transformers, one round torroid type and one standard type. Jerry, in your post I was thinking what you were referring to where transformers instead of relays if they were the sensing pick ups for the monitor panels. If they were truly the relays (and they may have been what was taken out) the relays are in the transfer switch box along with a circuit board.

Later Ed.

[Jerry Emert]

Jerry,

The relays and circuit board for the transfer switch is in one of the grey boxes and next to it is the box with the pickups transformers, one round torroid type and one standard type. Jerry, in your post I was thinking what you were referring to where transformers instead of relays if they were the sensing pick ups for the monitor panels. If they were truly the relays (and they may have been what was taken out) the relays are in the transfer switch box along with a circuit board.

Later Ed.

Ed, Jeremy, I had a brain fart, I meant transformers not relays.  when the transformers were bad, current on the monitor was indicated, AC volts were XXX and XXX.  Sorry about my confusion.
Jerry

[Edward Buker]

No problem, certainly before my morning coffee the brain fog has set in....it returns at will during the day.

Later Ed

[Jeremy Parrett]

Ed and Jerry,
   very helpful info.   The only other "grey" box in that area is the one with 4 breakers in it for the receptacles upstairs.
    I noticed there is a small set of wires going to it other than power cable so it may be that is where the CMP 10 AC Voltage sensors are?   Going to get the electrician to check today.

[Edward Buker]

Jeremy,

On mine, which is a 2002 Marquis, there is a grey box overhead in the storage bay near the inverter charger that houses the transfer switch. Next to it, a few inches away is a second grey box overhead with the transformers in it. There is a good reason to have the transformers used for voltage and current sensing near the transfer switch. If you find your transfer switch see if you have another grey box right near it. Hope this helps.

Later Ed

[Jeremy Parrett]

Ed,
  we just replaced the burned out transfer switch with a new Surgeguard  unit by TRC.  Rated at 50 amps it has additional protection for open neutral, low/high voltage, miswired / reverse polarity in pedestal etc.
  There only other grey boxes in the basement  is the 4 breaker box which has smaller wiring going into it as well as the regular wiring so it may be where the CMP voltage sensors are located.
  I will pop the lid tomorrow and check.

[Edward Buker]

Jeremy,

The sensors have to be incorporated in the main AC cable wiring route between the transfer switch you just installed and your main AC breaker panel. The monitor system would not work for both AC sources (genset and plug in) otherwise.

A separate grey box is still likely given the size of the 4 pickups involved. The photo I sent showed the size of the 4 transformer pickups, so you are looking for a place where those units could be housed. It would be possible to have them housed in the main breaker panel but I have not heard of that in these coaches. Someone else with your vintage coach may have an idea where they are or perhaps BCS.

Later Ed

[Jeremy Parrett]

Ed,
   perhaps some one with a 2000 Marquis can let us know where the sensors are?
  Gerald, did my old Prosine 3000 watt  Inverter/charger have telephone type connectors for the CMP 10 voltage sensors?
  I have 2 such connectors dangling beside my new Xantrex Freedom Inverter with nowhere to plug them in.

[Gerald Farris]

Jeremy, I think that the sensors that you are looking for are in the shore power box wiring in the rear closet.

The telephone wires were not for the CMP system. They were probably for the Prosine remote and/or a battery temp sensor. 

Gerald

[Jeremy Parrett]

Gerald,
  many thanks.  Will check the main breaker box.
                      Jeremy