Intellitec

[Mr11617]

2005 Diplomat 36SKT. When plugged into 50 amp all is working as it should. When plugged into 30 amp all works as it should. On last trip while running generator (800 diesel), intellitec only shows 30 amps. Checked with multi meter, getting 120 volts on both legs going into transfer switch. Getting 120 volts on both legs going out of transfer switch. Getting 120 volts on both legs of breaker panel. All breakers and all relays in breaker panel have 120 volts. When I try to run two AC’s intellitec starts shedding power. Does this point to a bad circuit board for the intellitec?

[Skip426]

Is this coach new to you ?

Or a new problem on a coach you've had for a while ?

[Mr11617]

Have owned the motor home for several years, new proem.

[Skip426]

The EMS, looks for voltage differences between the two legs of supply to determine 30 vs 50 amp .
With the EMS working on shore power and not from the gen set ; I would think the EMS is not the issue .

Have you tried cycling the breaker mounted on the gen set ?

[Mr11617]

Yes, I have. Both legs show the same voltage at transfer switch and at breaker panel.

[Mr11617]

After some research and thinking, i believe that the sense wire from the generator to the EMS is broken. I will trace that wire and see what I find.

[Mr11617]

Update! I just confirmed that the blue sense wire from the generator to the J2 plug in the EMS is broken somewhere. I put a jumper wire on the J2 plug and everything worked as it should. Now I just need to trace the wire from the generator and find the break.

[YC1]

Originally Posted by Mr11617

Update! I just confirmed that the blue sense wire from the generator to the J2 plug in the EMS is broken somewhere. I put a jumper wire on the J2 plug and everything worked as it should. Now I just need to trace the wire from the generator and find the break.

Greetings: Wow, joined in 2021 an just 5 posts. And it sounds like you are quite capable.

Try exercising the connectors on the cables attached to the side of the generator. They are known to have issues with starting and stopping and perhaps they could also be part of the feedback from the generator.

Just a quick thought, I wonder if that same (generator active/on) line feeds the BIRD board to tell it to not activate IF the generator and alternator are both active. I'm just curious about this and sometimes a clue is a clue.

With your feedback it sounds like you have documentation on the intellitec system which is half the battle.

[jacwjames]

The sense wire comes from the generator, it is a blue wire on my coach. First place to check it the inverter, you'll have to remove the cover where the wiring is.

From there mine went to the passenger side rear electrical bay, I had a BIRD there where it provided input to disable the chassis/house charging while generator was running.

From there it went to the generator start switch next to the bed.

From there up to the EMS panel.



You can try finding the break or it might be easier to just run a new wire from the inverter to the EMS.

[Tindalsj]

I have an similar failure that I have not yet started to diagnose.
In my case the Gen is correctly identified as 50 amp, but an actual 50 amp connection is identified as 30 amp.
If the load on one leg of the circuit gets to 30 amps it will start to shed loads. However, I can run both ACs because one of them doesn't show as used load.
This hasn't bothered me too much since I basically get the operation I want, but after reading this thread I'm thinking this is not working correctly.
No idea where to start looking

[YC1]

Here is a file I saved some time ago. Maybe it will help.

Are any breakers turned off, such as for the washer/dryer?

The EMS senses one of the lines and often that is used.