Wiring from solar to controller

jeepnudger · Senior Member

Wiring from solar to controller

Jaahn · Guru

jeepnudger wrote:
I have added another S.panel to my existing one now 2 x120watts. Question is should i increase wiring size to controller, is it reasonable to think that jayco would have put wiring a little larger . By using existing wiring if to small will iit heat up or what?

Hi Jeepnudger smile

It is unreasonable to expect the wires were oversized. It has been most peoples experience that the original wires are too small anyway. furious

The problem with small wires is the losses incurred in the resistance. You might loose a significent percentage of your solar power in the wires. So if you replace them with generous sized wires and as short a run as possible you will get 'free power' after that. You will possibly also need a new regulator/controller and should ensure it is mounted close to the battery for optimum effect and the wires to the battery should also be increased in size. aww

Read the other threads for more ideas. Good luck.

Jaahn

-- Edited by Jaahn on Thursday 21st of November 2019 09:09:26 AM

Peter_n_Margaret · Guru

What Jaan said....
However, it is only at full solar production that the losses will be highest. In times of poor sun, you will still get a significant benefit from the extra panel., even if you don't increase the cable sizes..... but why would you not get the full benefit for the sake of a few metres of cable?
Cheers,
Peter

T1 Terry · Guru

The 4.3mm sq cable they use for solar is enough for a 160w panel at the most because the cable is probably more than 6 mtrs long. There is often at least a metre curled up in the roof civility. If you now have 7 panels, you can't even solve the problem using an MPPT controller because the total voltage in series would be way too high for any controller on the market and the voltage would be mega dangerous even if there was. 500w is about the limit for 6 B&S cable over the 5 mtr run from the roof to the controller, so id it is another 5 x 120w solar panels you have added, you might even need 2 x 6B&S twin cable runs from the roof down. What controller will you be using? The capacity needs to be 60 amps or greater so the cable from the controller to the battery will need to be either 4 B&S cable or larger, or 2 runs of 6 B&S cable and you will still need to keep the run length as short as possible.

T1 Terry

Possum3 · Guru

T1 Terry wrote:
If you now have 7 panels, you can't even solve the problem using an MPPT controller because the total voltage in series would be way too high for any controller on the market and the voltage would be mega dangerous even if there was. 500w is about the limit for 6 B&S cable over the 5 mtr run from the roof to the controller, so id it is another 5 x 120w solar panels you have added,
T1 Terry

T1, OP has added one extra S Panel not 5 - time to see spec savers.

Tony Bev · Guru

One of the problems with Jayco, (or at least the Jayco Conquest, I have)

Is that it would be a right royal pain in the backside, to remove the original wires to the roof, to fit larger diameter ones

I did try to remove the original wires, but gave up, and placed that project, into the too hard basket

The wife was not really impressed, when I told her that I would be running wires, either down the outside of the motorhome, or down the inside wall

Whenarewethere · Guru

jeepnudger wrote:
I have added another S.panel to my existing one now 2 x120watts. Question is should i increase wiring size to controller, is it reasonable to think that jayco would have put wiring a little larger . By using existing wiring if to small will iit heat up or what?

What is the distance to the controller & the distance to the battery?

Are the solar panels in parallel?

Noelpolar · Veteran Member

I run 6 panels (800w).... 3 srings of 2 panels through the standard jayco wiring.... probally 6 meters of 4.5mm2 ish cable.... voltage drop will vary according to current flow...of course.... but I have sized my system to meet my needs in winter in the soithern half of Aust..... even at 20amps VD its only about 1 volt.... two 120w panels would be fine.

I considered running new cable... but could not see the need.... but I did series the panels for obvious reasons.... ie 800w ....

-- Edited by Noelpolar on Thursday 21st of November 2019 11:24:29 PM

Warren-Pat_01 · Guru

Hi Tony,
I weighed up the pros & cons of drilling holes in my roof, through the soft walls of the pop-top & came up with running my solar wires down the side of the van in 50x25 rectangular conduit (with a clip on lid). It helps if you can bring it down the side of the awning or in my case, down behind a window.

Pat ok'ed it (after I explained what the options were).

jeepnudger,
Jaycos are built to a price that most of us can afford & to assume they'd use heavier wiring is not good. For example, have a look at the size of the 240vac wiring that they use! But they aren't the only ones - newer stoves in houses have elements that cycle on/off. The reason (besides saving energy) is so they can use the smallest & cheapest wiring possible! The wiring would burn out if the elements were on permanently.

Besides if I built a van from scratch, it would probably weigh over 4t!!

T1 Terry · Guru

Possum3 wrote:
T1 Terry wrote:
If you now have 7 panels, you can't even solve the problem using an MPPT controller because the total voltage in series would be way too high for any controller on the market and the voltage would be mega dangerous even if there was. 500w is about the limit for 6 B&S cable over the 5 mtr run from the roof to the controller, so id it is another 5 x 120w solar panels you have added,
T1 Terry
T1, OP has added one extra S Panel not 5 - time to see spec savers.

Your not wrong there. I have been diagnosed with rapid onset macular degeneration in the left eye. Naturally that is my good eye. Started about a week ago, the photo and graph thing a spec savers has gone from a virual flat line on the scan/photo/graph thing when the test was done for new glasses, Monday the graph looks like an camel hump in the middle. The vision in the left eye distorts the overall vision and with the right eye shut the spot a week ago is now filling the whole vision in the left eyes. It's like looking through a window with water running down the outside of the glass.

I magnified the opening post and with the left eye closed I can see what I thought was a 5 is actually S. As I read it the post said "I have added another 5 panel to my existing one now 2 x120watts." To me that said the OP had added 5 panels to his existing 2 panels.

Probably best I stop trying to read and advise on any posts until it is sorted or stabilised, or I just accept I can no longer read and just give up trying to do any of the online help stuff at all.

So Jeepnudger, please ignore my post altogether because it was based on a completely wrong assumption on my part

T1 Terry

.

Tony Bev · Guru

Warren-Pat_01 wrote:
Hi Tony,
I weighed up the pros & cons of drilling holes in my roof, through the soft walls of the pop-top & came up with running my solar wires down the side of the van in 50x25 rectangular conduit (with a clip on lid). It helps if you can bring it down the side of the awning or in my case, down behind a window.

Pat ok'ed it (after I explained what the options were).

jeepnudger,
Jaycos are built to a price that most of us can afford & to assume they'd use heavier wiring is not good. For example, have a look at the size of the 240vac wiring that they use! But they aren't the only ones - newer stoves in houses have elements that cycle on/off. The reason (besides saving energy) is so they can use the smallest & cheapest wiring possible! The wiring would burn out if the elements were on permanently.

Besides if I built a van from scratch, it would probably weigh over 4t!!

Hi Warren

I have 300 watt solar panel on the roof, and so far the thin Jayco wires, are still suitable for my situation

As my AGM batteries are only three years old, and still suitable for my needs, it will be some time before I have to think about, increasing roof solar, and Jayco wiring

Thanks for the info, on how you have done it

Jaahn · Guru

Hi Terry :)
I am sorry to hear about your eye problems. It must be a shock to be aware it is going so suddenly :( Good luck !
Cheers Jaahn

Tony Bev · Guru

Hi Terry :)
I am sorry to hear about your eye problems. It must be a shock to be aware it is going so suddenly :( Good luck !
Cheers Jaahn

+2 so look after yourself, Terry

markf · Senior Member

Look after yourself Terry.

There are many online support groups out there some of them may even be useful.

There are also lots of tools available to assist the vision impaired among us.

jegog · Senior Member

I know how you feel, I have it on both eyes, worst in the right eye. Both eyes open is best but not for long I suspect.

I have Apple devices and find being able to easily resize things helps enormously.

T1 Terry · Guru

Thank you all for your support. I can finally sort of read the computer again thanks to a very switched on eye specialist in Adelaide. The first specialist could see the problem clearly and the rapid rate it had progressed in the few days between Spec Savers and his testing. Unfortunately it wasn't in his specialised field of vision correction so he sent me to another young fellow with a urgent attention needed" regarding an appointment for me.
I got in as the last double booked appointment 2 days later and the last spot before he set off on his weekly trip around the outlying centres, a 5 am start to head to Port Augusta the next day.
Straight on the line, wet macular degeneration in the left eye and dry macular degeneration in the right eye. 5 mins later he had me prepped by his nurse and stuck a needle in my left eye.
Now I'm on a life time one capsule a day medication (well additional to all the others) and monthly needles in the eye till it starts to stabilise. 95% chance it won't get worse and a 75% chance out of that 95% that there would be some improvement. I have to daily test the right eye to determine if it suddenly deteriorates and an opening for an appointment as soon as I detect any changes.
The chilling fact came when he told me if I'd waited 4 weeks from the first symptom I'd be so blind in that eye I wouldn't be able to identify the top letter on his eye chart, it was an A bigger than my hand .....
The big floating black spot has at least gone for the moment, the blurred and distorted vision is still there, but I'm getting better at automatically favouring the right eye for close up work so no need to close the left eye to identify what I'm looking at. Sadly, it seems I have lost a lot of my colour identification ability and need a bright light to determine the difference between purple and dark brown and black, and white, bone coloured, great and light blue. These are all wire colours I use for the 13 core harness that is part of our BMS system.
My wife Margaret is my trainee at the moment and does all the wiring etc that requires putting terminals on small cables and soldering anything smaller diameter than my fingers. Just trying to get a Phillips screw driver into the head of a screw is a challenge by the end of the day

T1 Terry