Using RF coax cable as DC Solar PV cable - Page 4

Xringer · 03-14-13, 03:33 PM

I re-adjusted them yesterday (they were way off angle).. Working better now.
I'm getting a nice amount of power out of the 800w array, considering the conditions lately.
Today we had over-cast+hazy, but once in a while it would get thin and a little brighter.
I looked at the power a couple of times and was surprised to see peaks over 600w.
I like the idea of reflected solar, but it's too big and complicated..

4 Practical Solar heliostats (time-lapse video) - YouTube

Neat eh?

Mikesolar · 03-16-13, 07:54 PM

What are the tiny PV panels on the bigger ones?

Xringer · 03-16-13, 09:49 PM

Each of those charges a 12V battery. Two are old car batteries in the house and the third, smaller battery that runs the tracker motor.
http://i46.photobucket.com/albums/f1...Solar/z010.jpg

http://i46.photobucket.com/albums/f1...kerbattery.jpg

terrapin8 · 12-01-13, 09:11 AM

Xringer,
The idea of using RF coax cable for solar panel DC is good (find new use for coax cable). There is plenty coax cable around the house. I was wondering is it safe to use existing coax cable for a low power solar panel rated 45W (12V about 4AMP)? I didn't understand you concern about arcing. Is arcing also an issue for 45W low power solar panels? I am thinking to use the exiting coax cable to connect the solar panel to the charger controller which is inside the house (about 50 feet). Any comments? Thanks.

Xringer · 12-01-13, 12:46 PM

Arcing is a serious problem with high voltage arrays, when switching the power on and off.
My 800W array can deliver 7 amps at about 114 volts.
That will not only kill you, but you could do a little welding with it..

If you are only using a single 45W Panel with 4A @ 12v, you shouldn't have any problems.
But, if you are using TV coax, with it's tiny center conductor, you should avoid
plugging or unplugging the cable while it's running power.
The arcing will be minimal, but can still cause contact point damage,
which can increase resistance, losses and maybe melting at the contact point.

There is almost zero shock hazard at 12V (just don't put the wires on your tongue)

and avoid holding small wires together with your fingers.
If the point of contact sees too much resistance, that contact point will heat up.
(Think about how hot a 45W soldering iron can get).

terrapin8 · 12-01-13, 08:47 PM

That's fantastic! Now I can reuse my existing satellite dish coax cable system for my solar panel (I was going to recycle it earlier). The voltage from the solar panel can be as high as 23v before going into the charge controller but I don't think it will make much difference.

The best part is that I don't have to drill holes on the wall to get the cable in because they are already there. I searched the internet for hours and I found that you are the only one who has experimented with coax cable for solar panels. I will cite your posting as reference. Thanks a lot!

Xringer · 12-01-13, 10:35 PM

My old C-band Satellite dish had coax cable and some 12 & 14 gauge cables out to the old dish mount. (For motor and servo wires).

I'm using that 20+ year old TVRO cable to charge up a couple of old 12v batteries,
from two 5w 12V panels, at the end of the 100 foot run..

One battery powers our master bedroom reading light (LED) and
the other one is for my Ham Radio gear in the basement.

Been working for a couple of years IIRC..

terrapin8 · 12-02-13, 06:16 PM

That's inspiring. I will try with my cable and solar panel.

BTW, speaking of old batteries, have you tried to use a "desulfator" on them? Does it really work? I looked at a few schematics including Alastair Couper's original version and did some circuit simulations but couldn't get the voltage and amps they mentioned. Not sure it really works or not.

Xringer · 12-02-13, 07:48 PM

I use a Schumacher SEM-1562A charger 'Maintainer' for my SUV battery, but it doesn't have a desulfator function.
I don't drive it much anymore. If we don't need to haul big stuff, we take the wife's Prius C2.

We replace car batteries every 6 years, so I'm able to cycle out my old junk 12V basement batteries.
When I buy a new car battery (we have two cars), I turn in my oldest 'basement' battery.

My 12V solar controllers are simple voltage regulator junk from China.
They were cheap and they don't over-charge, so I'm happy..

My next big battery problem is to replace my three year old 48v battery bank,
with real solar backup batteries..
http://ecorenovator.org/forum/solar-...r-project.html

I'm not sure, but I may have set the controller voltage too high and
lately the output performance has dropped off..

triumphman · 02-17-16, 04:09 PM

I have some cable that I bought from a cable installer. It has a thick black plastic outer shield, next a foil layer, next a braided wire layer, then another foil layer, and then a tough white plastic center, and finally the solid copper center. There are no markings anywhere. I gauged the center copper wire and got .042 to fit the size hole with the copper center wire. The cable tech. man said it was waterproof and I could bury it . My question is: can I use this to any purpose for 2 Harbor Freight Kits (45 watt each) equaling 90 watts. Connected together. Is it wise to use this type wire for solar ? Thanks for your expertise !

03-14-13, 03:33 PM	#31
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	I re-adjusted them yesterday (they were way off angle).. Working better now. I'm getting a nice amount of power out of the 800w array, considering the conditions lately. Today we had over-cast+hazy, but once in a while it would get thin and a little brighter. I looked at the power a couple of times and was surprised to see peaks over 600w. I like the idea of reflected solar, but it's too big and complicated.. 4 Practical Solar heliostats (time-lapse video) - YouTube Neat eh? __________________ My hobby is installing & trying to repair mini-splits EPA 608 Type 1 Technician Certification ~ 5 lbs or less..

03-16-13, 09:49 PM	#33
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	Each of those charges a 12V battery. Two are old car batteries in the house and the third, smaller battery that runs the tracker motor. http://i46.photobucket.com/albums/f1...Solar/z010.jpg http://i46.photobucket.com/albums/f1...kerbattery.jpg __________________ My hobby is installing & trying to repair mini-splits EPA 608 Type 1 Technician Certification ~ 5 lbs or less..

12-01-13, 12:46 PM	#35
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	Arcing is a serious problem with high voltage arrays, when switching the power on and off. My 800W array can deliver 7 amps at about 114 volts. That will not only kill you, but you could do a little welding with it.. If you are only using a single 45W Panel with 4A @ 12v, you shouldn't have any problems. But, if you are using TV coax, with it's tiny center conductor, you should avoid plugging or unplugging the cable while it's running power. The arcing will be minimal, but can still cause contact point damage, which can increase resistance, losses and maybe melting at the contact point. There is almost zero shock hazard at 12V (just don't put the wires on your tongue) and avoid holding small wires together with your fingers. If the point of contact sees too much resistance, that contact point will heat up. (Think about how hot a 45W soldering iron can get). __________________ My hobby is installing & trying to repair mini-splits EPA 608 Type 1 Technician Certification ~ 5 lbs or less..

12-01-13, 10:35 PM	#37
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	My old C-band Satellite dish had coax cable and some 12 & 14 gauge cables out to the old dish mount. (For motor and servo wires). I'm using that 20+ year old TVRO cable to charge up a couple of old 12v batteries, from two 5w 12V panels, at the end of the 100 foot run.. One battery powers our master bedroom reading light (LED) and the other one is for my Ham Radio gear in the basement. Been working for a couple of years IIRC.. __________________ My hobby is installing & trying to repair mini-splits EPA 608 Type 1 Technician Certification ~ 5 lbs or less..

12-02-13, 07:48 PM	#39
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	I use a Schumacher SEM-1562A charger 'Maintainer' for my SUV battery, but it doesn't have a desulfator function. I don't drive it much anymore. If we don't need to haul big stuff, we take the wife's Prius C2. We replace car batteries every 6 years, so I'm able to cycle out my old junk 12V basement batteries. When I buy a new car battery (we have two cars), I turn in my oldest 'basement' battery. My 12V solar controllers are simple voltage regulator junk from China. They were cheap and they don't over-charge, so I'm happy.. My next big battery problem is to replace my three year old 48v battery bank, with real solar backup batteries.. http://ecorenovator.org/forum/solar-...r-project.html I'm not sure, but I may have set the controller voltage too high and lately the output performance has dropped off.. __________________ My hobby is installing & trying to repair mini-splits EPA 608 Type 1 Technician Certification ~ 5 lbs or less..

03-16-13, 07:54 PM	#32
Mikesolar Master EcoRenovator Join Date: Aug 2012 Location: Toronto Posts: 958 Thanks: 40 Thanked 158 Times in 150 Posts	What are the tiny PV panels on the bigger ones?

12-01-13, 09:11 AM	#34
terrapin8 Lurking Renovator Join Date: Dec 2013 Location: USA Posts: 3 Thanks: 0 Thanked 0 Times in 0 Posts	Xringer, The idea of using RF coax cable for solar panel DC is good (find new use for coax cable). There is plenty coax cable around the house. I was wondering is it safe to use existing coax cable for a low power solar panel rated 45W (12V about 4AMP)? I didn't understand you concern about arcing. Is arcing also an issue for 45W low power solar panels? I am thinking to use the exiting coax cable to connect the solar panel to the charger controller which is inside the house (about 50 feet). Any comments? Thanks.

12-01-13, 08:47 PM	#36
terrapin8 Lurking Renovator Join Date: Dec 2013 Location: USA Posts: 3 Thanks: 0 Thanked 0 Times in 0 Posts	That's fantastic! Now I can reuse my existing satellite dish coax cable system for my solar panel (I was going to recycle it earlier). The voltage from the solar panel can be as high as 23v before going into the charge controller but I don't think it will make much difference. The best part is that I don't have to drill holes on the wall to get the cable in because they are already there. I searched the internet for hours and I found that you are the only one who has experimented with coax cable for solar panels. I will cite your posting as reference. Thanks a lot!

12-02-13, 06:16 PM	#38
terrapin8 Lurking Renovator Join Date: Dec 2013 Location: USA Posts: 3 Thanks: 0 Thanked 0 Times in 0 Posts	That's inspiring. I will try with my cable and solar panel. BTW, speaking of old batteries, have you tried to use a "desulfator" on them? Does it really work? I looked at a few schematics including Alastair Couper's original version and did some circuit simulations but couldn't get the voltage and amps they mentioned. Not sure it really works or not.

02-17-16, 04:09 PM	#40
triumphman Lurking Renovator Join Date: Feb 2016 Location: Northeastern,USA Posts: 2 Thanks: 0 Thanked 0 Times in 0 Posts	I have some cable that I bought from a cable installer. It has a thick black plastic outer shield, next a foil layer, next a braided wire layer, then another foil layer, and then a tough white plastic center, and finally the solid copper center. There are no markings anywhere. I gauged the center copper wire and got .042 to fit the size hole with the copper center wire. The cable tech. man said it was waterproof and I could bury it . My question is: can I use this to any purpose for 2 Harbor Freight Kits (45 watt each) equaling 90 watts. Connected together. Is it wise to use this type wire for solar ? Thanks for your expertise !