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Staley · 04-24-2010, 05:55 PM

I am a new owner of a very nice 96 Pace Arrow. I have upgraded the 30 Amp panel with a Parallax 500-12p24 50Amp box and and a ITS 50R transfer switch.

The AC/Heaters are controlled with an intellitec controller which had a current sensor on the main 30amp wire of the original 30amp panel.

Everything is working in the coach except the intellitec controller will not turn on the ac compressors. If you flip the switch to test front or rear, they will operate only in the test mode.

Does anyone have any tricks to fool the system into working, or wiring the load device somewhere into the panel? I have connected the load sensor on one of the smaller 15 amp circuits so it sees some sort of current draw and sends the AC signal to the intellitec unit. That still does not work.

Do I need to upgrade the ac controller to some 50 amp ac control unit?
I do not care if the shed functionality works or not.

Ideas?

Thanks!
Mike
Houston, TX

Gary RVRoamer · 04-24-2010, 06:24 PM

You really need the 50A model of the Intelletec if you want it to work right, but if you don't care, why not just remove the a/c circuits from the Intelletec controller. There is no requirement that they pass through the relays there if you do not want them to be load shed.

You can find service manuals for the Intelletec on their web site. I think what you have is called the Electronic Climate Control system - that's what I had in my 96 Southwind with two a/cs.
Service Manuals

Staley · 04-25-2010, 11:06 AM

It looks like I might have thrown in the towel just a little early. When I originally installed the load sensor on the main (red) wire of my 50 amp panel and turned on the ac units. the shed and on lights would blink and the compressor would not work. IF I would have only waited the 2 minute delay... they would have worked perfect.
Here are some photos of the upgrade.
Thanks for your help!
Mike

Picasa Web Albums - lmstaley2 - RV 50 Amp Upg...

Luv2go · 04-25-2010, 12:20 PM

Mike, congratulations on your upgrade, it is very well done and neat

!

One comment, putting the current sensor on one of the hot leads the current sensor may not be in the best position.

As you may know, the Intellitec ECC works by measuring the current through the current sensor and dropping one or both A/C's as necessary to keep the current under 30A. It does not care if there is too little current, only too much. For a good explanation, see the paragraph towards the bottom of p5 of this manual.

With 50A feed you have plenty of power and do not really need the load control, however when you run with a 50-30A adapter you will still need it. With 30A feed the black and red hot wires are paralleled by the 50-30A pigtail adapter so you will only be measuring half the current the coach is drawing.

Putting the sensor on the Neutral will measure all the current drawn with the 30A adapter, and the difference in currents being drawn by each of the 50A legs when you're hooked up to 50A.

I'd suggest the following:

Insure that each A/C is connected to a separate line, i.e. one A/C to the bus supplied by the Red wire side of the 50A breaker and the other A/C supplied by the Black wire side. This insures that you have a balanced load on your 50A feed when running both A/C's.

Move the current sensor to the Neutral wire. As I mentioned above, the Intellitec ECC really only needs to operate when you have a 30A feed, and putting it there will minimize it's effect when running on 50A. Intellitec EMS's for 50A have an additional relay that senses the 240V between the 50A feed hot wires and keep the system from operating at all when on 50A, but your ECC does not have that, and you should be able to get away with not having it with your A/C's balanced as above.

You could also remove the sensor from the red wire and just leave it hooked to the ECC. This will disable the load shed capability and allow you to run everything. The only time you'd get into trouble is when you run on 30A and use the 30-50A pigtail, you will definitely blow the 30A pedastal breaker by trying to run both A/C's and another appliance at once (been there, done that

).

Again, congratulations on your upgrade, hopefully your posts and pictures will encourage others who are battling the "not enough power" problem to do this upgrade.

Stewart

Staley · 04-25-2010, 07:06 PM

Stewart,
The neutral wire is an excellent idea. I tried leaving the sensor plugged in without any load wire thru it, and it would never kick the compressors on.

Since the original panel was 30 amps and the ECC was made to shed units around the 30 amp range, I think it would start to shed the units when I still have 20 remaining amps available plugged into a 50 amp box. Am I wrong?

The conversion was fairly straightforward. The most difficult part was routing the heavy 50 amp wire to the panel. It is routed in almost the same place as the original which is really cool.

Thanks again for your input.
Mike

Gary RVRoamer · 04-26-2010, 07:11 AM

Yes, it will still shed at 30A. That's why the 50A version has a bypass when it detects 50A service (240V) or when the generator is operating.

wa8yxm · 04-26-2010, 11:34 AM

The Load sensor should be on the WHITE wire.. That way it will not sense 50 amp loads.. The EMS systems need to measure voltage red to black

There are a couple of ways they can work but here is the basics.

If RED/Black voltage is zero.. You are hooked to less than 50 amps (30/20/15/0, yes Zero, means not plugged in)

So the controller will monitor current in the WHITE wire and shed loads as needed, only one AC will work

If on the other hand the controller senses 220-240 volts (Basically most any voltage) between Red and Black. it says "AH, 50 amps" and goes into "Turn everything on" mode.

Of course if you only have a 30 amp controller... It will not (CAN NOT) do that

Luv2go · 04-26-2010, 02:11 PM

Staley, it is interesting that it would never kick the compressors on when you did not put a wire through it. I would have thought that it would not care but after re-reading the manual I think I found the explanation. It says the shed timer is started "If the 120 VAC line current sensed by the Current Sensor goes below 1 Amp." This means that with no wire through it it measures 0A all the time and it may never time out and kick the compressor on (sort of like a retriggerable one-shot). There should be over 1A difference in Red and Black line currents, which would go through the Neutral line, so moving the sensor to the neutral line should still work OK.

You are right about your assumption of the ECC shedding at over 30A, with the current sensor where it is you would have 20A unusable from loads connected to the Red line side of your 50A feed. That's why moving it to Neutral would help, as the Neutral carries the difference in currents between the Red and Black line.

If Neutral current exceeded 30A (for example if you have the water heater electric element, the microwave and the A/C all hooked up and running on the Red side and nothing on the Black side) the load shedding would still start. That's why I mentioned the importance of balancing your loads.

If my reading of the manual above is wrong, it is possible the ECC could be looking for a load increase every time it added an A/C unit, in which case balancing the system by putting one A/C each on the Black and Red lines may not work and it will shed one of the A/C's when the second turns on. In this case you will have to put both A/C's on the same line so the ECC will see what it expects, may even have to put the current sensor back on that line, limiting it to 30A...

Let me know what you find out if you move the current sensor.

Stewart