Forum Discussion

farmer_boots's avatar
farmer_boots
Explorer
Nov 08, 2017

intellitec EMS controller

I found my front AC unit not working. The Dometic error code was E7 (120 power loss). Removed the circuit breaker panel cover and found the power was going into the EMS controller Model 760 but was not coming back out. I was on 50a circuit and all the other EMS circuits are working. I am assuming the K1 relay or the driver are bad on the controller.

I always keep AC running in the camper (Florida). So here is my question; for temporary purposes is there any reason I can't move the feed to my AC unit from the EMS board to the circuit breaker and get the front AC going again.

My plan is to pull the EMS board and troubleshoot the relay and driver. I am sure one of them is bad. I would rather do that for around $20 then pay $400 for a new board.
Class A
  • newman_fulltime's avatar
    newman_fulltime
    Explorer II
    Nov 08, 2017
    i doubt it is the board.
    real easy fix check the wire connections at the ac and at the breaker first.
  • dougrainer's avatar
    dougrainer
    Nomad
    Nov 08, 2017
    You can bypass any circuit on the Intellitec. It just will not be on the shed system, which is OK since you are on 50 amp service. I have never seen a relay fail on an Intellitec, but it can happen I guess. As long as you have NOT had anybody mess with the Intellitec control board(Change jumpers) and it just fails to close the AC relay, then the board is at fault. Doug
  • ScottG's avatar
    ScottG
    Nomad
    Nov 08, 2017
    If power is going into the EMS but not coming back out on that circuit, it isn't a loose wire at the AC or anything else down stream.
    You might give the relays a good tap in case it's stuck but I see no reason why you can't just move the AC over to another circuit if need be.
  • farmer_boots's avatar
    farmer_boots
    Explorer
    Nov 09, 2017
    We did have a few power bumps the other day. I will try tapping the relay to see if it is stuck. It sounds like there are no issues with just connecting direct to the breaker. Once I do that with critical circuits I will remove the card and troubleshoot. Hope it's just relays. Do I need to turn off the EMS system before removing the card? I assume the only way to do that is turn off house 12v power.

    Thanks
  • dougrainer's avatar
    dougrainer
    Nomad
    Nov 09, 2017
    The EMS has 2 power sources.
    1. 120 volts that is managed
    2. 12 volts that operate the EMS relays and display
    Yes, you want NO 120 volts in the RV when removing the EMS board. 12 volts is GONE when you remove the large small wire multi-connector on the Board. Intellitec, the relays are OPEN until the system is powered up. Then all the shed relay's CLOSE once the system powers up. Even IF you tap the relay and it closes, it is still BAD and will stick again, so you do need to replace the board. Make sure you label all the 120 wires going to the board. AND, there are jumpers you will have to set when you get the new board. You really need to download the installation manual for the controller (make sure it is the 760). Doug
  • farmer_boots's avatar
    farmer_boots
    Explorer
    Nov 10, 2017
    Today I tapped on the relay but it had no affect. Called the distributor (I think), they told me a new board would be around $350 and there was no value in the old one. So I decided to take a chance on being able to fix mine. Determined the relays are Omron G8P-1A4P 12 30A 240v SPST so I ordered 4 of them ($5 each).

    I bypassed the EMS for the front AC, this will keep it going until I can get the EMS card fixed or replaced.

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