In the Alpine 3640RL, there is a cabinet immediately inside the front door which holds all the controls. The Control Panel front is the typical thin luan paneling recessed about ½" from the door. Behind the luan panel is a 6" wide area for wiring backed by the typical covered plywood wall. This wall and the back of the shower form the drop area for the wiring access to the utility basement. There is a maze of wires behind the switches shown in the picture with a drop access behind the light switches ("Before" on "Control Panel.JPG").
The switch panel supplied with the Ultraheat switches was comprised of a labeled switch plate and a raised mounting bezel. The raised bezel might be good for a wall mounted switch panel, but within the Control Panel, it raised the switches too high and blocked the door. I chose to use only the labeled front plate and allow the switches to recess into the wiring area. I positioned the front plate in the upper right corner of the control area and marked the four outside corners of the actual switch area. Once the spacing of these corners was checked, I carefully etched and cut the rectangular area out with a Dremel tool. I carved down through the luan carefully to only "break" into the wiring area since I did not know where any of the wiring might be. Once this rectangular area was removed, I was able to use a telescoping mirror and small flashlight to view the wiring. There was no wiring behind the upper rectangular cut. However, most of the wires from the Onan Energy Command 30 passed behind the area I planned to mount the "basement circulation fan" switch (lower right). There was not a good way to move these wires. I marked an electrical box-sized opening in the lower right and carefully used the Dremel tool to cut about a quarter of the area out of the upper right side. This was just enough area to allow me to use my fingers to move the wiring slightly so I could (again) carefully use the Dremel tool to cut the upper left quarter. Once this was completed, I had enough area to move the wiring back and prop it with a small piece of wood. The rest of the cut was completed once the wiring was safely moved away ("Cuts and Wiring.JPG").
Because the luan is so thin, I backed the area above and below the labeled switch plate with two quarter-inch thick Poplar strips glued to the back of the luan panel. That gave the switch plate mounting screws a good bite to hold the plate, switches, and wires. I used a "light duty electrical box frame" (primarily used for telephone plates) to frame the switch box. However, since the luan is so thin, I had to wrap the "mounting ears" with about a quarter inch of electrical tape to allow the mounting ears to press the frame into place with the screws were firmly turned. I didn't want to run the wiring over and around the existing wiring, so I used a 1" wood spade drill to drill four vertical adjoining holes into the wire drop area behind the electrical box frame. This also made it easy to fish the wires at the basement level as they were isolated.
The UltraHeat labeled switch plate had places for five switches – exactly what I needed! I have a dual 12VDC/120VAC tank heater for the Fresh Water tank, and for the other three tanks I have 120VAC heaters. (Note: The Fresh Water and Gray1 tank heaters will not be installed for another month.) Each switch has an internal LED light. Using a multimeter, I tested to learn which position was the "off" position on the switches. I put five switches in the plate and used a white paint pen to add additional lettering. On the four 120VAC switches, I made a wiring loom for the neutral of the LED lights. I then made a wiring loom for the 120VAC source ("Cuts and Wiring.JPG").
The 120VAC tank heaters only pull about one ampere each, so I decided to use 16 gauge stranded pair wire for connections. Since two of the tank heaters are in place, I dropped a stranded pair wire for the black tank down the wiring drop. I then went around to the basement area with a wire hook (coat hanger) and reached over the furnace to capture the stranded wire. I fed the wire through the wire supports above the furnace. I cut the plug off the black tank wire and crimped the dropped stranded wire as an extension. I kept the polarization by crimping the ribbed side of the stranded pairs together and the smooth sides together. I returned to the Control Panel and pulled most of the slack out of the dropped wire. I labeled this wire with tape and pen "Black Tank" and cut it about two feet beyond the panel. I crimped a connecting spade to the smooth insulation side of the wire (hot) and stripped the ribbed side (neutral) for later connection. I repeated this procedure for the Gray2 tank.
As I do not have the other two tank heaters in place yet, I took three 20' lengths of 16 gauge stranded pair wire, labeled both ends (Gray1, 120VAC Fresh, 12VDC Fresh) and dropped them into the wire drop. On the Control Panel end, I put a connection spade on each of the smooth insulation wires and stripped the ribbed insulation side. Inside the basement, I snagged these three pair of wires, ran them through the wiring support above the furnace, and coiled them for later use. Back at the Control Panel, I used a cable tie mount to group all these wires and attached the tie mount to the wood cross brace. I did not fully tighten the cable tie yet and will do that once the heater switch panel is in place. I will leave a little slack in these lines so that there is no stress on the switches and prevent the wires from pulling out and dropping into the wire drop area ("Wiring.JPG").
The 12VDC switch for the basement warm-air input fans and the dimmer switch for the basement circulation fan will be discussed in those respective Modification posts.
DW and I decided when we purchased the Alpine not to have a washer/dryer. (Laundromats are fine with us and, besides, it makes clothes washing a quicker task!) I decided to use the 20 amp dryer circuit breaker as the input power lead for the 120VAC tank heaters and circulation fan. For this use, I dropped a length of 14 gauge solid wire into the wiring drop. For the power source for the 12VDC tank heater and the basement warm-air fans, I used 16 gauge stranded single wires (red and white) and dropped these wires bound by cable ties into the wire drop.
IMPORTANT STEP HERE! I disconnected the 50 amp power cord to the Alpine and disconnected the positive lead from the batteries! At this point, there is no electricity inside the Alpine!
I removed the cover of the power panel and fed electrical fishing tape from the front through the rear access port into the basement area. From the basement, I attached the 120VAC and the 12VDC source wires to the tape. From the power panel side, I pulled these wires through to the inside of the Alpine. I stripped and routed these wires along side the present wiring to put the black 120VAC source wire next to the lug for the dryer circuit breaker and the white 120VAC neutral wire next to the neutral connection loom. On the 12VDC side, I fed the wires along side the present wiring to put the red 12VDC source wire next to the lowest fuse (15 amp) that is unlabeled on the fuse panel and the black 12VDC wire next to the neutral wiring loom. Once I felt the wires were properly placed, I connected them to the respective breaker, fuse, and loom lugs.
Back at the Control Panel, I used a wire nut to connect all the 120VAC neutral wires and attached the 120VAC hot source wire to the hot source wiring loom. I attached a connection spade and lead for the warm-air fans to the end of the 12VDC red source wire and attached it to the back of the 12VDC heater switch. I then connected all the 12VDC neutral wires together.
From all appearances, it was time for a quick test before final mounting. I made sure all wiring was complete and there were no shorted connections. I pulled the 12VDC fuse and switched the dryer circuit breaker off. I then reconnected the positive lead to the battery and reconnected the 50 amp power cord to the Alpine. Back at the Control Panel, I switched on the dryer circuit breaker and carefully holding the labeled switch plate (so as not to get shocked), I flipped on and off each 120VAC switch. If the LED light came on at the switch, then I had a good connection. I then flipped the dryer circuit break off. I reinstalled the 12VDC fuse and tested the 12VDC switch. I then removed the 12VDC fuse.
At last, it was time to button all this up! I carefully fed and placed the wires, etc., into the rectangular hole and secured the labeled switch plate. I must admit, it looks pretty good! ("Close-up Control Panel, JPG") And, being the OCD person I am, I flipped the circuit breaker on and installed the fuse just to see if there were any sparks visible in the dimmer switch hole! Success!
Later in February I will have the last two tank heaters mounted on the Fresh Water and Gray1 tanks. It will be easy to connect these to the labeled power leads coiled in the basement. Until then, Happy Trails!
Ron
UltraHeat Tank Heaters, Part 2 - Control Panel
Linear Mode
