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brianseay1's avatar
brianseay1
Explorer
May 16, 2020

50amp Smart EMS ???

Got the rv out for the first time this season and have already ran into a problem. I noticed my AC units would not come on after I got set up at the CG. Everything works except the AC units and water heater when on electric setting. Microwave works fine, all lights are working.The things that go thru the EMS are the only things not working. I have no lights coming on at all on the panel board.
I did the following things
1)checked the 50amp breaker at the shore power connection.
2) checked breakers in my breaker box, all seem fine
3) checked fuse in fuse box for the EMS, fuse was fine. indicator light comes on when you remover the fuse.So I assume everything is good there.
4) started generator up to see if it would work off of it, but nothing changed.
Is there something I am missing ? I'm thinking the EMS panel has gone bad. But I hate to buy a new one until I know for sure that's what it is. Is there anything I can check or have I checked it all ? Any help is greatly appreciated, it is mighty warm inside the coach without AC.....
  • wa8yxm's avatar
    wa8yxm
    Explorer III
    May 16, 2020
    Sounds like you are not getting shore power.. Microwave may be fed by an inverter (likewise TV's) but all the things that are NOT working eat 120 shore power or generator only

    Suspect list in linier order
    Park breaker/outlet/power
    Shore cord plug, and if disconnectable the outlet
    RV inlet (If shore cord disconnectable)
    Automatic transfer switch (If you have a ganerator and an ATS)
    main breaker inside RV
    And the Energy Manager as well. Also a Surge Guard or like device (Some are called surge guards some other names (EMS) but the management system is also called EMS kind of confusing)
  • dougrainer's avatar
    dougrainer
    Nomad
    May 16, 2020
    "The things that go thru the EMS are the only things not working. I have no lights coming on at all on the panel board".

    THAT is your problem. It takes 12 volt power to operate the EMS board and the Panel board. You do not state brand of EMS, but Intellitec is the most common used. The Control board for the EMS is IN the 120 electric box where the breakers are. You remove the metal cover and you will see the control board. ON that board is a ATC 12 volt fuse. Make sure there is 12 volt power to that fuse. Doug

    https://www.intellitec.com/wp-content/uploads/2019/07/53-00911-000.pdf
  • brianseay1's avatar
    brianseay1
    Explorer
    May 16, 2020
    I pulled the board out this morning. It is an Intellitec 50 amp Smart EMS. When i plugged it back in the indicator lights came on for about 2-3 seconds and then back off. Unplugged it and plugged it back in again and the same thing. It lit up for 2-3 seconds and back off. Everything works on the coach except those that go thru this panel. I checked the 5amp fuse in the fuse panel for the EMS board and it is good. I am going to look for the fuse Doug is talking about. Thx for the replies.
  • brianseay1's avatar
    brianseay1
    Explorer
    May 16, 2020
    I pulled the board out this morning. It is an Intellitec 50 amp Smart EMS. When i plugged it back in the indicator lights came on for about 2-3 seconds and then back off. Unplugged it and plugged it back in again and the same thing. It lit up for 2-3 seconds and back off. Everything works on the coach except those that go thru this panel. I checked the 5amp fuse in the fuse panel for the EMS board and it is good. I am going to look for the fuse Doug is talking about. Thx for the replies.
  • dougrainer's avatar
    dougrainer
    Nomad
    May 16, 2020
    brianseay1 wrote:
    I pulled the board out this morning. It is an Intellitec 50 amp Smart EMS. When i plugged it back in the indicator lights came on for about 2-3 seconds and then back off. Unplugged it and plugged it back in again and the same thing. It lit up for 2-3 seconds and back off. Everything works on the coach except those that go thru this panel. I checked the 5amp fuse in the fuse panel for the EMS board and it is good. I am going to look for the fuse Doug is talking about. Thx for the replies.


    If it powers up for a few seconds, then the Fuse on the EMS board is good. Intellitec is a bad system in that ALL the controlled relay's for the shed appliances MUST have the Intellitec board operational. Failure and the 120 relay's fail to close and allow 120 power to the appliances. From you description you need a new Intellitec EMS control board. The remote display rarely fails. Your only solution until you replace the Board is to label EACH 120 wire at the relay's on the EMS control and wire nut the 2 wires together for each appliance. That bypasses the EMS board. MAKE SURE YOU HAVE THE 120 POWER OFF IF YOU DO THIS. You probably have 4 relay's maybe 3. The wires to be connected together will be next to each other. The link I sent is NOT for your specific system but for a 2 appliance system but the schematic shows how the wires and relay's work. Doug
  • brianseay1's avatar
    brianseay1
    Explorer
    May 16, 2020
    What do the relays look like ? I am assuming they are built into the board. And i am assuming the control board is the one inside the breaker box panel where i just checked the fuse. I appreciate you taking the time to help me out Doug.
  • brianseay1's avatar
    brianseay1
    Explorer
    May 16, 2020
    If I can just get my AC units going till I can get home I would be happy. The way i read it is to take the wire from the breaker and wire it to the wire coming off the board relay connections. Then I will have AC. Am I reading this correctly ??? I read the schematic and now know what the relays look like....lol
  • enblethen's avatar
    enblethen
    Nomad
    May 16, 2020
    Yes, you will be by-passing the EMS by connecting output from EMS to breaker.

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