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Stan&Jacquie · 09-22-2019, 08:42 PM

My '07 Knight DFT has a circuit board next to the fuse panel that is above the washer in the rear bath. The AC load management circuit is blown and I need to replace the board.

Where do I get my one?

Drifter · 09-22-2019, 09:19 PM

Check the numbers on the old board.

Look here at amazon, under $200
Intellitec

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Intellitec 0000911000 Powerline Smart EMS

jacwjames · 09-23-2019, 07:32 AM

Have you checked the small fuse on the circuit board and/or reset it.

M&M Electronics is a good resource and provide technical support. https://www.mmrvelectronics.com/

My EMS got hit with lightening and I ended up having to replace with a newer version requiring the board, load meter, and wiring harnesses, I ended up buying from M&M to make sure I got all the right components.

Stan&Jacquie · 09-24-2019, 08:00 PM

Hey guys, thanks for your replies. I'll get to pull it next week and check the numbers so I can order a new one. Your info is much appreciated. Stan

jacwjames · 09-25-2019, 07:08 AM

FWIW
When my system failed we getting ready to leave on a trip. I needed at least 1 AC unit to work so I just bypassed the EMS relay wiring the AC direct. We just had to watch out power consumption.

K7JV · 09-25-2019, 07:56 AM

Without knowing the details of your coach, the "load management" systems in our vintage of coach are not nearly as intelligent as we might have been led to believe. If yours is like our '06 Dynasty, all it does is look for load current on the washer/dryer circuit, and when it exceeds a pre-determined value, it cuts power to the rear A/C. As soon as the current drops below that threshold, the A/C is powered, once again. The load management that it does has nothing to do with shore power amperage limitations. It is merely allowing two relatively large loads to be powered by a single 20-amp circuit breaker.

As long as you make it a point to turn off your rear A/C while you are operating your washer/dryer, you won't have any problem. The worst case if you forget is that you will trip the 20 amp breaker. No harm. You aren't taking any risks other than risks to your convenience.

jacwjames · 09-25-2019, 02:37 PM

Mine must be different then yours in that it will distinguish between a 50 amp, 30 amp, or 20 amp shore power feed and limit power consumption by dropping loads from 4 circuits as it is monitoring total power consumption. In my case AC1, AC2, Water Heater, and Washer/Dryer. It also senses if power is being provided by the generator and then doesn't restrict power consumption.

twinboat · 09-25-2019, 04:59 PM

Quote:

Originally Posted by jacwjames

Mine must be different then yours in that it will distinguish between a 50 amp, 30 amp, or 20 amp shore power feed and limit power consumption by dropping loads from 4 circuits as it is monitoring total power consumption. In my case AC1, AC2, Water Heater, and Washer/Dryer. It also senses if power is being provided by the generator and then doesn't restrict power consumption.

It can't distinguish between 30 and 20 amps. Both are same 120 volt service.

How would it know ? Amps are what you draw, there not just there.

It monitors for 120 and 240 volts. That's how it knows 30 or 50 amp service. 20 is a selection.

It doesn't know the difference between 30 and 20/15 amps ? The house breaker would trip before it got to 30 amps.

jacwjames · 09-25-2019, 05:13 PM

twinboat
This is what is my 760 EMS manual

"If only 20Amp service is available, the user must select the 20 AMP service mode by momentarily pressing the 20/30 Amp select switch on the Control Panel. Initially, all relay contacts are closed and the total current is monitored. If the total current should exceed the service limit, the system will turn off the first load in the shedding table."

So I just assumed that it would monitor and shed so that amperage does not exceed 20 amp.

YC1 · 09-25-2019, 06:39 PM

Quote:

Originally Posted by Stan&Jacquie

Hey guys, thanks for your replies. I'll get to pull it next week and check the numbers so I can order a new one. Your info is much appreciated. Stan

As suggested, you can remove the board and use wire nuts to connect the inputs and outputs of the relays. You can then go on about your business and be careful to not trip breakers. I ran mine for months like this.

nodine · 09-26-2019, 05:20 AM

Quote:

Originally Posted by YC1

As suggested, you can remove the board and use wire nuts to connect the inputs and outputs of the relays. You can then go on about your business and be careful to not trip breakers. I ran mine for months like this.

Or just go to the front of the board where the screw terminals are for each shedding relay circuit and move the output wire to the the input side so that both wires are shorted together in the same screw terminal. Usually the relays are what fail and by using this method you can bypass only the defective relays. The most common failures are the rear and front AC shedding relays.

Bob

PlanBee · 09-26-2019, 08:19 AM

Funny I have the same thing going on right now. I lost the electric portion of the Aquahot. Found the relay burned to a crisp.

The relays are about $6. I will attempt to replace the relay on the board before buying the whole board.

I moved the wires under the relay for the washer drier and then put both the wires for the washer drier together under the hot wire from the breaker for now.

YC1 · 09-27-2019, 07:35 AM

I ordered replacement relays for mine. Once the board was out it was obvious it needed to be replaced and relays were not going to be an option.

To confirm the number on the circuit board I had to remove my board so just wire nutted things together.

Some way to cool the panel would sure help. I keep my closet door open during extremely hot days if not in the shade. One AC vent is pointed directly at the panel.

PlanBee · 09-27-2019, 07:55 AM

Quote:

Originally Posted by YC1

I ordered replacement relays for mine. Once the board was out it was obvious it needed to be replaced and relays were not going to be an option.

To confirm the number on the circuit board I had to remove my board so just wire nutted things together.

Some way to cool the panel would sure help. I keep my closet door open during extremely hot days if not in the shade. One AC vent is pointed directly at the panel.

I too am assuming the board will be beyond repair, but the relays are so cheap once I put the bus away for the winter I will give it a shot and wanted them on hand. It might be a good idea to cool things, I could add a temp controlled pancake fan easily enough inside the box. The temp of the other relays wasn't too high, they were ~112*. The screw terminal for the wire going out to the water heater was so loose I could pull the wire out without loosening the screw, it should have gotten hot at that point and not taken out the relay but electricity is sometimes mysterious. Seems common, I replaced the same relay in a board for an oven a few years back also.