Skip to main content ↑ ↓
Topic: Solar Tie In (Read 773 times) previous topic - next topic

Solar Tie In

Planning on putting some panels on roof (400 watts) thinking to put charge controller in area at foot of bed and tie into isolator terminal that feeds front battery bank any thoughts.

Thank You Joey
1996 U270

Re: Solar Tie In

Reply #1 –
Shortest route to batteries is best. Pretty easy to go down through refrigerator vent.
Doug W.
96 36' U270 CSGI #4946
04 Toyota Tacoma 4x4
PNW

Re: Solar Tie In

Reply #2 –
Sounds good to me. That is one of three places where heavy cabling to the house batteries (or the batteries themselves) can be accessed. The other two being the equipment bay next to the inverter-charger, and the area behind the kick panel in front of the passenger ( which is likely too small).

I put mine beside the inverter, which is one partition away from the house batteries.

You don't want to place any electronics in the same compartment as the batteries.
Tom Lang K6PG (originally  KC6UEC)
and Diane Lang
2003 38 U295 build 6209
2016 Jeep Grand Cherokee Summit Ecodiesel
still have tow-ready 2006 Acura MDX 
Temple City, California
Motorcade 16681 California Chapter President
SKP 16663 member of SKP Park of the Sierra, Coarsegold California
FMCA F071251
Retired electrical and electronic engineer

Re: Solar Tie In

Reply #3 –
I would clarify by stating "no spark-producing electronics in an enclosed compartment with lead-acid batteries."
1997 U270 34FT Build 5140 Cummins 8.3 Allison 3060R
Solar 1920Watts, 14KWH lithium. Orion BMS.

Re: Solar Tie In

Reply #4 –
Quote from: Breaktime –
Planning on putting some panels on roof (400 watts) thinking to put charge controller in area at foot of bed and tie into isolator terminal that feeds front battery bank any thoughts.
Where ever you put the charge controller, it's best if it's not in a confined space. In front of the foot of the bed would be good but not inside the compartment. As Doug says, the shortest way between the controller to the batteries is best. Welding cables are an excellent solution for cables. Put a fuseable link where you attach the + cable at the isolator, 12V bus or the battery itself. Bring the big cables up to next or behind the controller using a lug to attach it to a mounting surface and then run very short wires but as large as the controller will take at it's connections. I ran the roof panels to circuit breakers and another set between the controller and the big cables. This way, you are protected in case of a short. See my detailed photos of the installation here: U300 36' Solar Installation - Google Photos

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: Solar Tie In

Reply #5 –
Here is how mine is done..

Re: Solar Tie In

Reply #6 –
On my 96 270, I never considered connecting to the isolator.  I came down from the roof into an overhead cabinet, then down through the wooden tunnel behind the driver's seat (remarkably easy to open and gain access) and hung the controller on the wall between the tunnel and the driver's side window.  Then routed down from the controller to the house batteries was easy for the heavy cables out of the controller, down the tunnel to the floor behind the sofa, and drilled a hole into the battery compartment.  No matter how you go, have phun.  Andy1
Carolyn and Lewis (Andy1) Anderson
1996 U270 36'

Re: Solar Tie In

Reply #7 –
Not sure of your floor plan but with ours it was a straight shot down the fridge compartment which straddles the battery and storage bay.  Your run then becomes about 8-10 feet.  You can then mount it on the opposite side of the bulkhead from your batteries.  If you look close at bottom left you can see the 4 wire heading into battery bay but I don't have acid battery's but routing should not be an issue. 

A bit of heresy, I would mount 3 160s length wise and not the larger panels to reduce heat.  That is a personal preference.
George and Steph
1997 U270 36 Build 5081 "Honu"
1180w Solar 400A lithium all Victron house system
Motorcade 17670, SKP 128300, FMCA F459019
73 VW Camper, 79 VW Camper, 2363 Sunline, and an Arctic Fox 25P

Re: Solar Tie In

Reply #8 –
James. looking at your picture, just a suggestion that you fasten that Victron Inverter down as it could get damaged while driving. >:D  ^.^d
JohnH
Coachless, now use aircraft. 2003 Ford Travelair TC280 class C. Super shape. Just for 1 yr .
1994 Ford E350 ClassC,total renovation inside and out. Now sold.
2000 U295  36' Cummins 350 c/w Banks Stinger, Resonator upgrade,Solar, LED lites.Residential fridge with slide out pantry. Build 5674. Sold
ex 92 GV 022C ored Cummins. Sold
ex 95 GV240 cat 3116. Sold
2017 Mini cooper s & 2016 land Rover LR2 HSE  LUX.
jhaygarth@aol.com    SKP #130098
treat everyone as you would like to be.

Re: Solar Tie In

Reply #9 –
Quote from: George and Steph –
A bit of heresy, I would mount 3 160s length wise and not the larger panels to reduce heat.  That is a personal preference.
Are we talking about solar panels on the roof? If so, why not larger panels?

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: Solar Tie In

Reply #10 –
Pierce, I want the clearance under the panel to provide greater air flow.  Mounting a 160 longitudinaly is a trade off that made sense to me to reduce heat.  Given the arc of our roof and the diminished clearance that results with larger panels. 

I am getting ready to remove the nonslip black square by the ladder and lay up with chop and gel coat.  When I was at Xtreme, they recommended getting it off as it leads to delamination from heat.  Having worked with fiberglass, it is an easy fix for me.  It was a logical extension to panels as I saw it.

So as I said, it is a personal choice but one I thought was best for us.
George and Steph
1997 U270 36 Build 5081 "Honu"
1180w Solar 400A lithium all Victron house system
Motorcade 17670, SKP 128300, FMCA F459019
73 VW Camper, 79 VW Camper, 2363 Sunline, and an Arctic Fox 25P

Re: Solar Tie In

Reply #11 –
Just a tid bit. If you need to run small wires for batt sensors to the start batts, or need to run them to the front, I have gone into the belly, found the "extra wires" EXT1 EXT2 or so, and taped into them . Saves a ton of work.
CW
Chris and Tammy White  CDA Idaho
Previous owners 1997 U295 36' 3126 Cat 300 HP Build # 4998
Former Foretravel tech & RVIA certified tech
Former owner Custom Satellite home/RV satellites 
Former owner Vans LTD  van conversions
Unemployed, panhandler, drag racer NHRA #6348

Re: Solar Tie In

Reply #12 –
Two recommendations:

1 At least 4 inches of clearance of air space is recommended for the most heat flow / dissipation, based on my internet research.
2. I painted a 15 ft by 2 ft strip of white non-skid boat paint for my solar upgrade. It is made for exterior fiberglass get coated surfaces. It must be good because it took days to get it off my hand. West Marine sells it. I lightly sanded the gel coat and cleaned with 90% rubbing alcohol.
1997 U270 34FT Build 5140 Cummins 8.3 Allison 3060R
Solar 1920Watts, 14KWH lithium. Orion BMS.

Re: Solar Tie In

Reply #13 –
A few years ago, when I started adding solar, I laid one flexible panel on the roof.  It was a hot sunny SoCal day. After a while I went up with my IR gun and found the same temperature on the white roof, on the panel, and on the once black square.

I've seen no problems.
Tom Lang K6PG (originally  KC6UEC)
and Diane Lang
2003 38 U295 build 6209
2016 Jeep Grand Cherokee Summit Ecodiesel
still have tow-ready 2006 Acura MDX 
Temple City, California
Motorcade 16681 California Chapter President
SKP 16663 member of SKP Park of the Sierra, Coarsegold California
FMCA F071251
Retired electrical and electronic engineer

Re: Solar Tie In

Reply #14 –
George,

Installing the panels fore and aft is a good idea with good clearance underneath for good airflow, cooling. The 300 watt panels are not that wide at about 39 inches so can be mounted a couple of inches higher so the curved roof has enough airflow. One member just sent a PM with some nice 315 watt panels at a very attractive price so will have a 1260 watt potential. His roof is also curved so will have to raise them a little higher than we did to get a flat installation. I'm sure he will share installation photos for others with a curved roof to examine. The only challenge here is finding four lengths of 77 inches on the roof to mount the panels without too much modification. Most panel manufacturers recommend 2 inches between the panel and the RV roof (3" mininum on a house). Ours have about 1.75 plus the distance between the frame and the actual bottom of the panel. Our roof stays pretty cool. Don't think it would be a big deal with less in the middle for a curved roof.

96" Foretravel owners will have to be a little more inventive to squeeze the panels in without going over the side. Think it can be done but will have to engineer mounts close to the edge.

FYI: commercial panels for solar fields are commonly 39x77 inches and 36 volts with load. They may say, "not for RV use" in the literature but other than putting an extra mount in the middle of the long part, there was no problem. Nice aluminum frame on them so will take some abuse without damage. Almost 8 years working well now.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: Solar Tie In

Reply #15 –
Pierce, Tom, Tim

Next sunny day I will climb up and get some IR measurements.  Very curious and will enjoy seeing actual temps.  I will post with pics. 



George and Steph
1997 U270 36 Build 5081 "Honu"
1180w Solar 400A lithium all Victron house system
Motorcade 17670, SKP 128300, FMCA F459019
73 VW Camper, 79 VW Camper, 2363 Sunline, and an Arctic Fox 25P

Re: Solar Tie In

Reply #16 –
The measurements you request may be inaccurate because they don't take into account the fact that solar panels heat up when a panel is almost in full sunlight, but shaded by a long branch.  Almost an additional 300 watts of heat load could be dissipated by the panel.
1997 U270 34FT Build 5140 Cummins 8.3 Allison 3060R
Solar 1920Watts, 14KWH lithium. Orion BMS.

Re: Solar Tie In

Reply #17 –
Quote from: Tom Lang –
A few years ago, when I started adding solar, I laid one flexible panel on the roof.  It was a hot sunny SoCal day. After a while I went up with my IR gun and found the same temperature on the white roof, on the panel, and on the once black square.

I've seen no problems.
Agree. Had 1200 watts of  flexible panels on my roof, not much difference in temps between them and tops of non running ac's and vents.
Did check inside coach roof temps, less than two degrees difference between areas with panels overhead, and no panels.https://nebula.wsimg.com/067a0b086bcdbb011d73c983b5cabcee?AccessKeyId=69CC3057D53E066A8205&disposition=0&alloworigin=1
Jim C.
coachfree, previous 1997, 1999, 2000, and 2003 Foretravels.

Re: Solar Tie In

Reply #18 –
Thanks for posting the article.  If I read that right, the panel with 21mm air gap, .8 inch, was 20C, 68F, cooler than the flat mount.  My initial concern was not internal temps but the impact of high temperatures on the layup.  By the way the "extreme" temperature they are using of 43C, 109F, is 5C cooler than Phoenix yesterday.
George and Steph
1997 U270 36 Build 5081 "Honu"
1180w Solar 400A lithium all Victron house system
Motorcade 17670, SKP 128300, FMCA F459019
73 VW Camper, 79 VW Camper, 2363 Sunline, and an Arctic Fox 25P