Friday, January 18, 2019

Solar Junction Box Replacement

We have been experiencing water intrusion into our AM Solar junction box on our 2013 Majestic for over three years that we know of.  We added caulk to the lid screws and to the cable gland entrances, but still experienced water intrusion into the box.  We finally decided to just replace the entire box when we opened it up this fall and found water right up to the buss plane.  The corrosion was terrible and it was obvious that most of the box assembly was not suitable for cleanup and reuse.  Our 2013 New Horizon Solar Option we believe was an AM Solar kit of four each 100 W solar panels and the Tristar MPPT-45 charge controller.

Below is the before photo of original AM Solar junction box on the roof.
After photo of the replacement junction box below.  By assembling our own box parts, we saved about $70.
We believe that the original AM Solar box is found for $80 at  https://amsolar.com/rv-combiner-box/20-roof
We are unsure if the cable entrance glands come with the AM Solar box, but we know the cable glands on our original box did not have a rubber gasket or o-ring between the gland shoulder and the exterior box wall.  We suspect that is where most of the water was getting into our original box.  We also note that the AM Solar box did not have a o-ring gasket on the lid, which makes that box more of a dust-proof rather than a weather-proof enclosure.

Photo screenshot of AM Solar box for sale online below.

We found a generic project box on Amazon for $12.  It turned out one of the four lid screws was missing upon delivery, and we wrote that in a review online.  The seller immediately contacted us and provided a complete refund.  That saved us about 1/3 of the cost for a completed new box assembly.  The lid screws were zinc plated, so we just replaced all four with stainless steel screws from Ace Hardware.  We found the box here https://www.amazon.com/LeMotech-Waterproof-Dustproof-Universal-Enclosure/dp/B075X11CL6/ref=sr_1_5?s=hi&ie=UTF8&qid=1545005088&sr=1-5&keywords=LeMotech+Waterproof+Dustproof+IP65  This box had an o-ring gasket around the lid and all four lid screws were outside the inner enclosure for weatherproofing the contents.

The link page screen clip is below.

OK let's look a little closer at the existing installation.  A bit of a mess...
The box was mounted too close to the toilet room fan lid.  A sharp cable bend and a cable clamp screwed into the roof was required to prevent interference with the fan lid.
A view below with the lid removed.  The water has been removed from the interior of the box and it is dried out in this picture.
A little closer for additional detail.
Close in on the buss bars.  Note the significant corrosion.  Not abundantly visible are the wire strands that did not make the installation into the buss, they were frayed out.
The new box and cable gland assemblies.
Inside of new box.   Possibly visible is the white o-ring in the lid at right.  Note the integrated standoffs in the floor of the box interior at left.  We used these standoffs to mount the buss board.  Also the lid screws are designed outside of the weatherproof enclosure space preventing any water intrusion through the lid screws from getting to the box contents.
Below are the cable entrance glands that we found on Amazon, which fit the solar panel 10 AWG cables perfectly.
https://www.amazon.com/uxcell-Waterproof-Plastic-Adjustable-10mm-13mm/dp/B07DC7WHHD/ref=pd_rhf_pe_p_img_11?_encoding=UTF8&psc=1&refRID=5YTMRQG1MVAB7H1WNVZX
Below is a shot of the buss board we assembled.  The buss bars we found on Amazon and the plastic board was an RV bug-shield we found in the dumpster.  A little bit of cutting, filing and drilling and we had a perfect back board.  We mounted the board to the integrated box standoffs with three small stainless steel sheet metal screws which can be seen in the picture below.
A screen clip of the buss bars from Amazon below and a URL https://www.amazon.com/Square-Schneider-Electric-PK7GTACP-Terminal/dp/B002FQKSKO/ref=pd_day0_hl_60_5?_encoding=UTF8&pd_rd_i=B002FQKSKO&pd_rd_r=47fbe98b-0194-11e9-add8-73a0b1357621&pd_rd_w=cKWTW&pd_rd_wg=j0yHw&pf_rd_p=ad07871c-e646-4161-82c7-5ed0d4c85b07&pf_rd_r=32FJPJH31W9SW8D1TJ09&psc=1&refRID=32FJPJH31W9SW8D1TJ09
The terminal openings easily accommodated the 10 AWG stranded cables from the panels and were just large enough to accommodate the larger  stranded cable going down into the coach roof, 1/0 AWG I am guessing.
Beginning the existing box removal process.  First thing we did was disconnect the charge controller from the batteries, which was a re-settable 12V, 50 A fuse, and covered the panels with an opaque tarp.  Cables are removed from the buss and box in the picture below.  We had to cut the cables because the buss bars were frozen with corrosion.  New box at the ready for fit checking.  It was ironic how many tools and materials were required to deal with the two little boxes removal and replacement process.
A little closer on the buss bar corrosion damage.
Old box removed, caulk and butyl tape removal and clean up required.
A little closer in on the old footprint.
 Caulk cleaned off.
Closer in on the cleaned footprint.  There were three screws holding the old box down and one screw for the cable clamp to the right keeping one cable away from the fan lid.  We filled those existing screw holes with butyl tape and caulked over with Dicor self-leveling sealant.
Bottom of original box; lots of butyl tape.
Inside of original box, it's trash now.
Replacement box below.  Butyl tape applied to bottom of box, panel cables stripped and ready, buss bars standing by.
New box installed below.  We were very careful installing the stranded wires in the buss bars and think we got all of the wire strands into the buss holes.
We did a few things to combat moisture and corrosion in this new box.  First, we think this new box is truly weather-proof, the cable glands have rubber washers at the box/shoulder interface and the box lid includes an o-ring around the perimeter, we made a generous desiccant pack from an old handkerchief and silicon granules, we covered the stainless steel box mounting screws with butyl tape, and lastly we covered the buss and exposed wire ends with dielectric grease after they were securely fastened.
The desiccant pack fits nicely inside the box.
Ready to secure the lid below. 
 All the required tools and materials...
All cleaned up.  Good voltage on the busses.
The last detail was adding a new white cable loom.  The original black loom was damaged when previously removed and replaced during our year one roof replacement.  The original black loom had also become brittle from UV and was starting to come apart.  Perhaps the white color will endure a little longer, we will see.
We are getting a little better charging current now after replacement.  It was amazing that the system was still working as well as it was with the amount of water and corrosion inside the box.

Tuesday, January 8, 2019

Mouse Shields

When living in an RV, sooner or later you are going to have mice getting in and trying to take up residence.  One of the first things we did with our RV was to crawl everywhere we thought a mouse could access and if there was an opening, we squirted expanding foam in the void.  We are sure this helped a great deal, but then occasionally we would see signs of a mouse, but couldn't find an opening.  We finally decided that the water hose entrances were a primary access point for these uninvited visitors.  Initially we didn't think a mouse could get past the rubber fingers surrounding the hoses, but  we often observed mouse signs in the wet bay, right near the hose entrances.  We have two hose entrances into our wet bay, one for fresh water and the second for black tank back-flush influent.  This year we decided to take action and figure out an improved barrier over the rubber fingers.  We did a beta test with a small section of sheet metal that we obtained from a local Ace Hardware store.  With a couple of custom cuts we made 5 pieces that we thought would improve the situation.

This first picture below is a view inside of our wet bay.  The two hose entrances are at the bottom; fresh at frame left, and backflush at frame right
Below is the beta shape that we cut from the sheet metal.  I think we used a cashew can to mark the outside diameter, and a quarter to mark the center hose diameter.  We just drew two straight parallel lines from each side of the center hole to the edge of the cutout.
 First side placed on the fresh hose opening.
Second piece going on the fresh hose opening.
Fresh hose entrance protected with beta design.

Both hose entrances covered and weighted with spare combination wrenches.
This shot below is a sheet metal panel that will be used when in travel or dry camp mode and the hoses are not hooked up.  It lays over both hose entrances, and then we have a piece of custom cut foam that goes over top of that plate.  The plate is cut so that it is a close fit between the outer wet bay wall and the interior wall seen.  This will help to keep it in place.
Below is the custom cut foam.  We made this a few years ago.  We keep quick connects on the influent water ports, and cap them when we are disconnected.  The foam fits snug under the quick connects and between the walls.  We like the foam as an insulator when we are in cold situations, which we try to minimize!
Back view of the foam.  The back flush hose has a smaller cheaper quick connect fitting.
We store the metal plate and foam at the back wall of the wet bay, they just fit.
We keep a spray bottle with a bleach/water solution for hooking up hoses.... and the sponge is handy on bad days!

Sunday, December 23, 2018

Living the RV Dream

We regularly use some of our time in Arizona to perform maintenance, especially the outside work on our trailer Penelope.  The weather is very predictable in Sun City, most days are sunny and clear.  This visit we decided it was time to remove and replace all of the caulk on the trailer roof.  This was not a job that we looked forward to getting into, in fact we kind of dreaded it.  We ended up spending most of two weeks on the roof and applied more than a dozen tubes of Dicor sealant.  Once we got going, it wasn't as bad of a job as we had imagined, but we still don't classify it as fun, although it is definitely a part of the adventure of living in an RV.

Gari removes old caulk up on the roof.
Gari working on the front cap joint.
Gari surveys her progress.  Only about 18 inches remains in the middle of the front cap joint.
Back cap joint complete with new Dicor self-leveling sealant.
Close up at roof ladder detail.
Driver's side rear corner completed and drying.
Passenger side edge seam completed.
Close up on passenger side seam.  Self-leveling Dicor.
The finished product.  We even removed the solar panels and reworked the attachment points.  All three Maxx Fans  were removed and the mounting flanges reworked.
Gari washes the roof like a pro after all the caulking work.
More trailer living; Gari defrosts the freezer...
Living the RV Dream! Lol