Randyretired Posted May 23, 2019 Report Share Posted May 23, 2019 5 hours ago, Ray,IN said: . Randy I think the 50A main breaker panel in older RV's have redesigned bus bars that prevent the application of a 240VAC breaker. Of course a new panel may be installed whenever desired. Perhaps one of the sparkys can supply correct information. Ray, you may be right on some older rigs. It's impossible to know every breaker box used so I tried to use terms like most. For what it is worth my 1999 Teton has a 240 volt capable box. Quote Randy 2001 Volvo VNL 42 Cummins ISX Autoshift Link to comment Share on other sites More sharing options...
rpsinc Posted May 23, 2019 Report Share Posted May 23, 2019 As to framing the cassette opening, yes, double joist it in the opposite direction to the rafters/joists in your roof. I will be doing some cassette installs in my home and I have trusses and my larger cassette in my 2 zone system is about 28" square, so in the direction of the trusses I can jsut cut the drywall but where I have to cut the truss that is in the way, I have to cut it back far enough to be able to add double framing(2X4, 2X3 or whatever is there) so as to support the load that I removed. And the cassette has NO STRUCTURAL WORTH. If you make your opening slightly larger so that you can use some plywood as a box, which will come down and act as a chase to hold your cassette(will you need any space above the cassette for air gap?). Dont forget about access for your line set and your condensate drain too. And the drain should have some fall, so that you dont over flow your pan and spill inside. A/C supply houses have some nice covers for these lines etc, made for dressing up the lines and drain. As to the electrical, you COULD simply wire this one as a stand alone sub with a cord, wired to 240VAC and a breaker. Later, you just plug that cord into what ever you will do in your solar configuration. Quote Marcel Link to comment Share on other sites More sharing options...
GlennWest Posted May 23, 2019 Author Report Share Posted May 23, 2019 Actually it has a pump. I will be building the box so it is above roof line. Cassette will be 4" above roof. Calls for 3/4" clearance. Need to make it serviable up top bit haven't decided how yet. The unit will go in from the inside. Up top is the freon hookups. They will be just above roof. Works out just right there. Planning to screw plywood top on and cover with etherbond. Just remove screws to get to gas lines when needed. Got better mouse trap? Quote 2003 Teton Grand Freedom towed with 2006 Freightliner Century 120 across the beautiful USA welding pipe.https://photos.app.goo.gl/O32ZjgzSzgK7LAyt1 Link to comment Share on other sites More sharing options...
rpsinc Posted May 23, 2019 Report Share Posted May 23, 2019 23 minutes ago, GlennWest said: Actually it has a pump. I will be building the box so it is above roof line. Cassette will be 4" above roof. Calls for 3/4" clearance. Need to make it serviable up top bit haven't decided how yet. The unit will go in from the inside. Up top is the freon hookups. They will be just above roof. Works out just right there. Planning to screw plywood top on and cover with etherbond. Just remove screws to get to gas lines when needed. Got better mouse trap? What about a skylight for service access? Attach it to the plywood box. Try Icon. I like the idea of it being above the roof and running the lines on the roof. Maybe put your solar panels above the lines, on short standoff brackets. That can help keep them out of the direct sun. Quote Marcel Link to comment Share on other sites More sharing options...
kb0zke Posted May 24, 2019 Report Share Posted May 24, 2019 Back to the original question, assuming that you have sufficient access to all of the rafters involved, I would go with centering the unit on the rafter that will be cut. I'd double the other two rafters, then build the box for the unit. I would glue and screw everything. I'd use a GOOD marine-grade or aircraft-grade plywood and coat it with the best waterproofing compound I could find. Make the box as tight to the unit as you can so that it can't slide around. Yes, that means that everything has to be absolutely straight, but that will also give you the strongest structure. Quote David Lininger, kb0zke 1993 Foretravel U300 40' (sold) 2022 Grand Design Reflection 315RLTS Link to comment Share on other sites More sharing options...
GlennWest Posted May 26, 2019 Author Report Share Posted May 26, 2019 Well I ordered a 12k Pioneer Cassette Mini Split today. Decided to keep my current, working great, 110v unit. Just add the 240v unit to berdroom. This way also I will have 24k total. With the two unit system maxes out at 17k. I have room at rear for the second unit just need to remove ladder. Also will still have ac even at a 30 amp park, if I ever get in one. Quote 2003 Teton Grand Freedom towed with 2006 Freightliner Century 120 across the beautiful USA welding pipe.https://photos.app.goo.gl/O32ZjgzSzgK7LAyt1 Link to comment Share on other sites More sharing options...
GlennWest Posted May 26, 2019 Author Report Share Posted May 26, 2019 On 5/23/2019 at 6:16 PM, rpsinc said: What about a skylight for service access? Attach it to the plywood box. Try Icon. I like the idea of it being above the roof and running the lines on the roof. Maybe put your solar panels above the lines, on short standoff brackets. That can help keep them out of the direct sun. Plan on mounting solar level with top of box. Wrap hole roof up and leave a center walkway. Looked at Icon skylight. Would have to build box to fit skylight. I will have plywood left over so build top and wrap with eterbond tape. Put gasket on bottom and screw down and caulk screws. Quote 2003 Teton Grand Freedom towed with 2006 Freightliner Century 120 across the beautiful USA welding pipe.https://photos.app.goo.gl/O32ZjgzSzgK7LAyt1 Link to comment Share on other sites More sharing options...
rpsinc Posted May 27, 2019 Report Share Posted May 27, 2019 16 hours ago, GlennWest said: Plan on mounting solar level with top of box. Wrap hole roof up and leave a center walkway. Looked at Icon skylight. Would have to build box to fit skylight. I will have plywood left over so build top and wrap with eterbond tape. Put gasket on bottom and screw down and caulk screws. Sounds like you have a solution figured out Glenn Quote Marcel Link to comment Share on other sites More sharing options...
GlennWest Posted May 27, 2019 Author Report Share Posted May 27, 2019 (edited) Built the box today. All glued and screwed together. Put top on with 4 screws to hold square while glue sets up. Decided to make it 26" inside to have some working room. Outside is 27.5" so be close to each ajoining rafters. If my rafters are at 32", all I need is a 2x4 screwed to side of rafter to tighten against my box. Another reason I went larger. Edited May 27, 2019 by GlennWest Quote 2003 Teton Grand Freedom towed with 2006 Freightliner Century 120 across the beautiful USA welding pipe.https://photos.app.goo.gl/O32ZjgzSzgK7LAyt1 Link to comment Share on other sites More sharing options...
GlennWest Posted June 15, 2019 Author Report Share Posted June 15, 2019 Cut the interior hole yesterday. Surprised the area was already boxed in very well. Put it where factory air was. They boxed that area in with 2X6's. I had very little supporting to do. Cut myself short on ethernabond. Covering box took it all. Some more be here Monday and weather permitting will cut hole in roof then. Glad I brought a shop vac a while back. That was quite a mess. Oh, I took an early rof( reduction of force) from job to get this done. Quote 2003 Teton Grand Freedom towed with 2006 Freightliner Century 120 across the beautiful USA welding pipe.https://photos.app.goo.gl/O32ZjgzSzgK7LAyt1 Link to comment Share on other sites More sharing options...
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