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DUAL POWER ADAPTER

 

Imagine you could UNPLUG the rear air conditioner. Totally disconnnect it from the RV and plug it in independent of anything else.

That is EXACTLY what the PSRV adapter does.. Provides the rear A/C with a completly independent power source, No common anything with the rest of the RV.

No tripping of the GFCI, No common ground, (Save on the 12 volt side) Neutral or hot wire, It is completely separated from the rest of the RV.

Special Instructions for 50 AMP Coaches

These instructions are for installation of the DUAL POWER Adapter for a coach that has a 50 amp electrical system and dual air conditioners or a basement dual central air conditioning unit. The Dual Power Adapter will break into the 20 amp circuit that feeds the second AC unit and allow the attachment of a shore cord to feed the second AC directly.

Figure 1 shows a block diagram of the power system of a 50 amp coach for reference, showing how the Dual Power Adapter is installed.

Figure 1 – Power System

Dual Power Adapter

Additional Parts for installation

Parts that may be needed are 12/2 w/ground romex, medium wire nuts, romex connectors, possibly a 4" square x 1.5" deep junction box and hardware to secure the junction box and romex.

Coach Variations

First we need to determine the best method of installation depending on the coach. If the coach has two roof top AC units, the best method is to wire from the circuit breaker panel.

Follow the CB Panel installation below. If the coach has a basement central AC unit, you have the choice of doing the CB Panel type installation or the AC Unit installation. Look over the coach and read both installation methods to determine the best way to proceed. If there are any question, please call for technical support before proceeding.

CB Panel Installation

1. Locate the circuit breaker(CB) for the second air conditioner(AC) by doing the following. Start the generator and turn on both AC's. Turn off the generator CB that controls the second circuit, usually the lower one. One AC will be turned off. Go to the coach CB panel and turn off an AC CB. If the only running AC stays on, then this is the CB for the second AC. If the only running AC goes off, turn the CB back on after waiting one minute. Turn off the other AC CB to verify that it is the one that goes to the second AC. Turn on the generator CB.
Still only one AC should be running. Turn on the second AC CB, both AC's should be running again.

2. Open the cover to the coach CB panel.

3. Refer to Figure 2. Locate the second AC CB. Disconnect the black wire and label the wire #2.

4. Disconnect the white wire that goes to the same romex cable from the neutral bus terminal and label the wire #4.

Figure 2 – Coach Circuit Breaker Panel

Dual Power Adapter

5. Disconnect the white wire that goes to the same romex cable from the neutral bus terminal and label the wire #4.

6. Measure from the Coach CB Panel to the outside compartment where you want to mount the DUAL POWER adapter, either in the shore cord compartment or other outside compartment. Look for an opening or pipe that brings in other romex cables that you can route the two new romex cables through. In most cases you will be able to find a hole that is large enough to go through, it probably will have some sealer to be removed and replaced later. Cut two pieces of 12/2 w/ground romex the length you need. Remember to allow extra at both ends. Mark both ends of one of the cables with a permanent felt tip marker. This cable will be called Cable B.

7. Route two new romex cables from the Coach CB Panel to the compartment where you want the DUAL POWER adapter mounted.

8. Find an available knockout hole in the Coach CB Panel. Strip the outer jackets on the romex allowing plenty of wire to work with inside the box. Insert the both romex into a romex connector and attach it to the Coach CB Panel.

9. If you are not using an existing junction box to mount the DUAL POWER adapter, mount a 4 inch square by 1.5 inch deep box where you want it. Remember that the clearance in front of the junction box must be 6 inches.

10. Insert the two romex with a connector into the junction box. 11. Go back to the Coach CB Panel. Make the connections as shown in Figure 3 below. Connect the ground wires to the ground bus. Connect the Cable A white wire to the neutral bus. Connect the Cable A black wire to Second AC CB. Connect the Cable B white wire to white wire #4 you labeled above. Connect the Cable B black wire to the black wire #2 you labeled above.

Figure 3 -- Coach CB Panel with DUAL POWER Adapter cables

Dual Power Adapter

AC Unit Installation

1. Locate the AC unit and the two romex cables that go into the unit.

2. Determine a mounting place for a junction box to use for mounting the Dual Power Adapter that will allow you to disconnect one of the romex cables and swing it over to the junction box.

3. Remove the access cover to get at the wire connections.

4. Look at the connections to determine the #2 AC unit connections.

5. Disconnect the black wire and label it #2. Disconnect the white wire and label it #4. Remove the ground wire. Remove the romex from the AC unit.

6. Add a new piece of romex long enough to go from the AC unit to the junction box.

7. Mount the junction box and install the romex that you removed and the new piece of romex.

8. Use one of the junction box mounting screws to connect one of the ground wires leaving a tail to connect the other ground wire using a wire nut.

9. Connect the #2 black wire that you labeled to the #2 of the Dual Power Adapter using a medium wire nut. Do the same for the white #4 wires.

10. Connect the #1 black wire to the new romex black wire. Do the same for the #3 white wire. by BarryBeam 2003 U320 40'

 

Since the above company is no longer around you can basically run our rear AC during very hot weather on a campground 20 amp GFCI outlet because it can plugs the rear air directly into a campground outlet. When not using a separate campground outlet, the rear air is connected right back to breaker box for normal campground or generator operation. We just used this method again for several days in 100 degree temps and we were comfortable inside.

We went into main breaker box and disconnected the original Romex from rear air conditioner from circuit breaker (black wire), common neutral bus bar (white wire) & ground bus bar (green wire). We have two new short pieces of 12 Romex extending outside of breaker box near bedroom floor.

Inside the breaker box we connected one the new Romex cables to the connections where we just removed the rear AC wires, breaker, neutral & ground. The other end of this wire has a Romex compatible female socket.

Inside the breaker box we connected the 2nd new Romex to the original rear AC Romex cable using wire nuts & electric tape. The other end of this wire has a Romex compatible male plug.

Just plug the male into the female for normal operation. This connection is near our floor in front of bed.

rear AC Cable

Rear A/C Cable

rear AC unplug

Rear A/C unplugged

To run the rear AC on campground GFCI outlet, plug the new male Romex plug into a #10 extension cable that has its male end plugged into the campground GFCI outlet. How the extension cable gets from the bedroom floor is a matter of personal creativity. It could be a simple as running the extension cable out a window.

We wired a new household kitchen 20 amp duplex outlet to a male plug in the water bay. For normal operation the outlet's male plug is in a motorhome bay outlet. To run rear air on GFCI, we plug the bay plug into an extension cord that is plugged into GFCI. Then we run a #10 extension cable from kitchen outlet to bedroom floor rear AC plug. This way we don't rely on running cable through a window.

Another way would be to permanently run a new Romex from a bay into bedroom. BarryBeam above did it a different way by running two new Romex cables from breaker box to bay, and for normal operation the two Romex's are connected together. To connect to GFCI the Romex's are separated with the rear AC connected to GFCI.

No reason why a 2nd transfer switch would not work, but the same cables would have to be run. by Barry and Cindy 1997 U270 36' 6/16/14

© Barry Brideau 2003-2014