[Chester Stone]

David, see photo of 3 port AlummiConnector
   

[David and Teresa]

David, see photo of 3 port AlummiConnector

Thanks so much!

[bikestuff]

For the connector...Lowes is you friend. HD not so much.

[David and Teresa]

I was able to complete this mod on my single AC unit today. Everything works fine. Now to try this with the second unit.

[David and Teresa]

Does anyone know the values of the varistors on the dual SCS 305-2547 pcb? They're not listed in the manuals I have. After success with the single card (and getting it all to work), I'm attempting to see what's ailing the dual card that is blown. (see earlier pics). So far, all the relays are good, all the traces are good, except where burnt, and it seems all varistors but one are blown. I can't tell the manufacture, but the numbers are 150L10 9734 and it looks like 150L10 9713. The locations are VR1 through VR6.

[dreemail]

Hi Chester / Richard.  I have the same AC Circuit board (305-2547 REV A) and two compressors.  I appreciate all the diagrams and photos you have provided too.  Thank you.  

My question is coming the day I tried to wire this up for a test.  

The A1 A2 wires required that I cut the original wire and then connected these directly from the circuit board to the A1 and A2 sides (and Low Voltage) on the Eaton Relay (C25ANB125A).  
[Q1]: What do I do with the original wires that I cut?  Are they no longer used?  Or spliced into and remain?

The L1/L1 (120V) Is also confusing to me. The color diagram shows the the 120V wires are clearly connected to the Top and Bottom on the Eaton relay.  But then there is a little green and little black (top of digram) connecting back to the circuit board.  And the same at the bottom of the diagram except they are little green add little red. 
[Q2]: is this an actual spliced connection?  I assume that it is looking at your diagram (shows photos of he Eaton Relay) and other Finke labled diagram (Schematic).

Im not sure when you will get this or respond, but I find writing it out helps me work through the problem.

[Richard]

Q1. The end of the wire you cut that is not connected to the relay leads to the compressor. The hot wire of the pair will be powered by the contractor. The neutral wire will need to be spliced into neutral.

Chester chose to picture the original 120V connections on the board. Keep in mind, you are looking at a schematic.


Q2. All of the connections are spliced since none of the original wires are long enough to reach outside the enclosure where the contactors are mounted.

Call me at 817 223 2056 if you need interactive help.

[dreemail]

Thanks Richard.  Im going to attach my current set-up. I think I a missing the boat on a few of the connections.  I have seen a few of the drawn out schematics but find them difficult to fully understand,  in fact there is one right on my AC that I will attach since it is so clear.  I think this should be fairly simple since it is explained here, but the is my first Relay project on the 96 HR Navigator.  I can call at some point too but right now Im trying to get a visual understanding.

Dreelan 1996 HR Endeavor Pusher.pdf Size: 1.07 MB  Downloads: 21

schematic-1.pdf Size: 2.01 MB  Downloads: 22

schematic-2.pdf Size: 1.73 MB  Downloads: 11

[Richard]

We are in the hinterlands of New Hampshire, so my interweb connection is flaky. I cannot download your attachments.

I just got your version of the schematic downloaded. DO NOT wire the setup to that schematic. You are connecting hot to neutral in the contactor and you will created a dead short.

I am not necessarily known for diplomacy, so take this with the good spirit intended. You might want to watch a few U tube videos of how to read a schematic and some on how relays work before you wire anything up.

That being said, let me take a crack at explaining what you are doing. Presently the current and voltage to run the AC compressors runs through the board. The purpose of the external relays is to take the voltage and current for the compressors and offload the voltage and current to external relays. We are going to use heavy duty relays (otherwise known as contactors) with 120V coils.

We are going to use the schematic to find the two wires from the control board to the compressor. Snip those two wires into. Think about what we have when we do that. The wires coming from the board will have 120V on them when the board tells the compressor to come on. The board does not know the wires have been snipped. Use those two wires to energize the coil in the relay. When the coil is energized, the big contacts will close in the relay.

But, more connections need to be made to get power to the compressor. The two leads that were snipped to the compressor are hooked to nothing at this point. The hot lead will go to the contactor, the neutral lead needs to be tied into neutral. But the compressor still has no power because there is no HOT going into the contactor. The HOT coming from the coach (Black or Red) should be connected to the other side of the contactor.

When this is done, the board will send 120V to the coil of the contactor, since one side of the contactor is connected to the hot (black or red) side from house power, and the other side of the contactor is connected to the hot input of the compressor the compressor will now have a hot leg. Remembering the neutral to the compressor is tied into the neutral, the circuit will be complete and the compressor will start.

If this is not comfortable to you, you may want to think about hiring an electrician. Miswiring could harm the compressor, the control board, or most importantly you.

[dreemail]

Hi Richard-

Thank you taking the time to explain that.  My electrical understanding is about a 5-6 on scale of 1-10.  That is why I have never plugged my first attempt to the shore or land- line in to test it.  What I had done and shared -- It didn't make sense.  I know enough to trace the circuit and knew I was missing something.  You explained that.  The original wires to the compressor have to be correctly moved to the 120v relay, and to neutral.  That puts the relay into use (when also attaching the 120v White or Black --not both-- to the Relay).  I have redrawn my diagram with all of these connections shown.  And will attach soon.  It is now attached.  I have a question.  Since this RV has two compressors (two new relays) do I wire each relay exactly the same?  I read somewhere in this thread that one relay should use White instead of Black for power to balance the load?  Thank you.

'96 HR Navigator 40' of fun
Cummins Engine
Onan Gen