[Richard]

Let me try to explain what I am suggesting.

You have two sets of power wires that feed the control boards. One is white and black and attaches to the control board at the top. The second is red and white and attaches at the bottom. White is neutral of course and Black and Red are the two legs of 120 VAC power. You can measure current draw by clamping your ammeter around the wires that feed the board, BUT it can potentially confuse the issue. The black and white power to the upper attachment will have the current of the number one compressor, and both fans on it. The red and white power on the lower attachment will have the compressor number 2 and high speed for the condensor fan on it.

The best place to measure the current to the compressor is on the wiring that comes from the board and goes to each compressor. That wiring only powers the compressor, no other loads.

Are you measuring current on the wiring coming the board from the coach, or on the wiring between the board and the compressor?

I am sorry I am having such a problem with the English language.

[Chester Stone]

My posting on the 17th gave both the incoming amps plus the amps going to the compressors. My posting yesterday gave only the amps going from the control board to the compressors, before and after splicing and switching the connectors.

[Richard]

Thank you for the clarification.

You may have two problems. I definitely feel that the compressor with the low amperage is low on gas, since the low amperage followed the compressor when you switched.


Also you may have a control issue. Do you have the SCS manual? There is an excellent table in there that says which control wires should be activated in all of the different scenarios. It would be easy enough to plow through that table with the voltmeter on the output terminals of the thermostat or input terminals of the control board.

[Chester Stone]

Richard, I do not thing the low amperage followed the compressor. When the connectors to compressor 2 were connected to compressor 1, and the connector of 1 went to compressor 2, the low amperage moved from 1 to 2 and the high amperage moved for 2 to 1. This indicates to me that both compressors will operate at high amperage when either is connected to number 2 power source. After the switch, the unit will operate on low whereas in its original configuration, the unit would run only on high. I will check to see if I have the SCS manual and if not I will get back to you.

[bikestuff]

Chester, you said that the thermostat was replaced. I would start there to double check the wiring.

When Newell replaced one of my thermostats they told me that the new one did not have the capability to control both compressors. I could choose to run one or both (from a wiring perspective).

The manual is in the documentation section on gurus. http://newellgurus.com/showthread.php?tid=1711

[Chester Stone]

Yes, I have a four page owner's manual and an installation manual which seems to have the checks you are referring to. I will see where it takes me, but I am of the opinion that the low amperage is caused by either the thermostat or the control panel, not the compressor section.

[Richard]

Chester,

Thanks again for the clarification.

I am not disputing your conclusions, but I am terribly bumfuzzled and perplexed by the situation. I am not an electrical wizard by anyone's imagination, so I am asking for help understanding this one.

What in the circuitry or the thermostat could possibly cause the compressor to only pull 4 amps? Either the relay on the board closes or doesn't close to provide electrical continuity to the compressor. It is obviously closing, since the Number one circuit provides power to either compressor attached to the number one circuit. The circuitry turns the power on or off to the compressor, there is no mechanism for limiting the current that I am aware of.

[Richard]

I have a really nutty idea.

Chester, can you check the voltage going from the board to the capacitors for compressor 1?

[Chester Stone]

Richard, from what I observe, it is the number 2 compressor system that will provide full power to either compressor, and number 1 only provides the four amps. Today I will double check the wiring from the thermostat and see if I can check the voltage from the number 1 side as well as the number 2 side.

[Richard]

The reason I am asking is if some miswiring is in place and the voltage to number one is 220 not 110 then the amperage would be half of normal.

Or the "lands" on the board for number one are compromised, raising the resistance, and only 4 amps can pass through.