Travel Trailer Electrical Upgrade

[bruss01]

And, after all that... would you believe the hot coil sensor isn't working? It comes on, but isn't resetting. Feels hot to touch... must be an internal defect causing it to heat up from the current alone ( no external heat source). Replacement on order.

[bruss01]

Terminal block connection index:

Terminals identified by position (left to right) and upper (U) vs Lower (L) - wire called out by color. This list follows the basic current-flow through the system.


6L (red) - Power in from fuse
6U (red) - power out to master switch (ring)
5U (red) - Power return from master switch
5L (yellow) - Power out to ambient temp sensor (power on rise 85 degrees)
4L (black) - Power return from ambient temp sensor
4L (red) - Power out to coil temp sensor (power on rise 130 degrees)
3L (red) - Power return from coil temp sensor
3U (yellow) - Power out to fan array
3L (white) - Power out to LED (fan "on" indicator)
2U (black) - Power return from fan array
2L (white) - Power return from fan on indicator (LED)
2L (black) - Power return from master switch indicator light (ring LED)
2U (black) - Return to system negative

Each wire, before the ring terminal was attached, was fitted with a heat-shrink number tag to identify the wire's position on the terminal block. I had these on hand and decided to use them so if I ever had to swap out the block it'd be easy to get them all back on the right terminal. My screw up was that two of the wires on termnal #2 are labeled "5" by mistake as I lost my orientation for a sec and counted from the wrong end of the block. Oh well, it seemed like a good idea...

This may seem complicated to some (because there were many shortcuts and economies to be had, for sure) but my rationale for building it this way is as follows:

1 - I wanted all the connections to be in an easily accessible place in case I need to maintain or modify the wiring.

2 - pulling the fridge is a bear. It's not a one-person job without great effort and I typically travel alone on these trips.

3 - I wanted to be able to put jumpers across the connections, or swap them, on-the-fly while in the field. This configuration allows me to do that fairly easily. I can bypass a malfunctioning sensor that won't trigger, for instance, or hot-wire across a broken switch. I can test for juice at various points in the circuit with comparitive ease, if something's not working, and narrow down the problem.

Heavier-than-needed wire (12 gauge) was used to prevent voltage drop to the fans because of the length of the total circuit for the fan motors. Smaller gauge wire (14 or 16 I believe, what I had handy) was implemented for the LED power/return connections as those have minimal current requirements.

Heat-shrink crimp-on ring terminals were used for the terminal block connections. The marine-grade (waterproof) wasn't necessary for moisture prevention as much as it was for the added strength the melty-stuff (glue?) inside the MG HS fitting. Those aren't going to pull off.

Initially I had thought to just use the factory plugs on the fans and gang them together - I even got a Cat-O-4-Tails connector for that purpose. However, once I got into calculating the power needed it was almost an amp, 15 watts, and the factory cords were long and very tiny gauge wire. I ended up clipping them off at a couple of inches and using one of the mounting rails as a negative bus (wire from the end of the bus going back to neg on the terminal block) and attaching the fan ground to the bus with soldered-on ring terminals for a solid mechanical & electrical bond. The positives also got clipped and were soldered into a long yellow 12 gauge wire. Given how small those fan wires were, I didn't trust just twist connectors... considering that I'd have to pull the fridge to fix one that comes loose. The solder was covered with marine heat-shrink to add to the mechanical bond and provide insulation. I don't trust electrical tape.

[Rich_Vale74]

That, sir, is what I'd call done right.

[bruss01]

Replacement hot coil sensor arrived. Plugged into fan circuit, ran it thru 2 heat cool cycles with the heat gun, all appeared to work as intended. Next up, the baffle and insulation. Feels good to be making headway again.

[flock6]

Good job, glad to hear you got it straightened out.

[bruss01]

Wee bit o'progress.

Got the baffle installed, and some insulation.

Baffle (some sheet aluminum)


From underneath - you can see how the fans are inset, which necessitates the baffle.


To get a good seal on top (and protect the wires) I elected to use foam weatherstrip and a cover strip of firmer aluminum.


With a bit of spray-on adhesive the aluminum baffle was then covered with 1/4" styrofoam insulation (came as packing material in something ordered online)


Foam sheet insulation side panels installed.


Next weekend I should be able to finish insulating the fridge cabinet. I want to do fiberglass on the right side and top where there is presently a lot of empty space. The baffle was covered with styrofoam because the air on one side is HOT having just come through the radiating fins on the fridge, and I want to keep as much of that heat as possible from collecting in the "atic" space above the fridge, fiberglass or no... just seemed like a good idea. Super-insulating the fridge should help improve the "keep cold in" efficiency, while the fans and baffle improve the "remove heat from coil" efficiency. I'm hoping for another 20-30 degrees out of this setup on 100 degree days, and reduced energy consumption on normal days. Sure, 25 degrees is technically "frozen" but have you ever had 25 degree ice cream? It's practically soup. Five degree ice cream... now that's a treat on a searing summer day.

[bruss01]

My recent foray into GMRS radio gave me pause for thought... It is easy now, with the fridge out, to run an antenna lead up top the same as I have for the Wifi.

I don't have the radio yet but I figured it's better to install the antenna now and worry about the radio later.




I snapped the above pic prior to going back up top to do a bit of cable management. It's mounted to the tv aerial which is a crank up - crank down type so all the antennas lay flat to the roof while on the road.

No big deal, one of those trivial effort now or big job later sort of things. I was reminded while up there not to neglect the roof... looks like there are a few places where re-sealing wouldn't be a bad call.

Parts:
Midland 3 meter antenna cord (RG174 cord, PL259 connector both ends)
Midland antenna mounting bracket (NMO connector, SO239 connector)
Midland 6 db gain antenna (Mount type NMO, tuned 462mhz)
2 stainless screws, sold separately

Did not use the bolts and 2nd mount plate with the mounting bracket... Just 2 screws through the holes on the primary, into the antenna mast.

The top of the trailer is 8-10 feet (estimate), tv mast is 3-4 feet, and the midland is probably another 3 feet. So max, I estimate 17 feet, still under the legal limit of 20 specified by FCC for GMRS operation.

Radio coms for the Ritz is something that has been on my mind for a while. This upgrade gives us a "base" station for excursions out of cell tower reach. Could come in handy.