Cables and Isolator switches incredibly hot

[Bl4d3]

Hi all

So we've had a solar system for just about a year now.

In December I noticed a burning smell in the garage where the solar system is (isolator switches, batteries, inverters and DB boxes).
As I was soldering that day, I assumed I accidently burnt something with the soldering iron and just left it.

Suddenly solar power was lost and I investigated further. 1 of the 30A fuses inline with the solar feed had blown. We replaced it thinking it was a manufacturing defect.
Shortly after that the smell became worse and I noticed what looking like melting on the 1 isolator switch. We shut down the system and pulled out the switch which was completely destroyed due to arcing.

We called and whatsapped the electrician who installed the system with no response on 22 December. Thinking he is on holiday we left it and decided to sort it out ourselves.
We bought exact replacements to what was installed, and replaced the destroyed isolator switches and fuses.

We then noticed the few next day of full sun that the cables are getting extremely hot, hot enough that the sheathing is able to slip on the copper cable. The electrician got back to us that he would come by as soon as he is back from holiday.

Jump forward to 19 January, the electrician has still not come through, we sent a follow up message. No response.

Yesterday (23 January) we noticed that the isolator switches are even hotter (rated to 63A at 240V AC), so hot that if you were to hold it for more than 3 seconds, it would most likely burn your skin considerably.

I ended up leaving the electrician a bad review on his google page, he then responded all most immediately in a belligerent manner. The gist of his response is that he is still on holiday, its not right that I left a 1 star review 1 year later, he never dealt with me but dealt with my father, that my review is spam and that he will come on Monday.

I of course took up the matter with him because he would not respond to my fathers calls or messages and considering that such heat could potentially cause a fire.

 

To me, something seems terribly underrated in the system and is unable to cope with the amperage. I cant find an amperage rating on the cable, only that its solar rated.

Our solar setup is as follows :
9 x Canadian Solar 360w panels
1 x Axpert Close 5kva / 4kw inverter
2 x 100AH LiFePO4 batteries

Edited January 24, 2021 by Bl4d3

[Blowdart18]

7 hours ago, RRR said:

-- deleted by moderator---

Powerforum does not condone abuse of members

One makes me think you might be the installer considering you have been on the forum for 3 years and this is your 3rd post. 

 

Coming out of the block you attack OP, calling him a "-- deleted by moderator---" and that he should let grown-ups sort it out. Clearly you might be the one going about doing stuff the wrong way to be honest, as this forum is used as a platform to help and educate people on these matters and put them in touch with people that can assist. 

 

Also your comment here: "-- deleted by moderator---" - Unfortunately if you want to run a business you should be able to take the punches, regardless if you on holiday or not, it is still your business and decency would dictate you respond to your clients and keep to your word of sticking to an appointment. 

 

What recourse do consumers have when business owners cannot be held accountable, if OPs house burnt down because the installer did not correctly install the equipment what would you say? Even after a year you can still be held accountable for an install if the incorrect equipment was installed.

 

Edited January 27, 2021 by Moderator2
Quoted post contained abuse

[JustinSchoeman]

Ewww. That does not look like a DC rated isolator.  If it is ever switched off under load, it will just arc until enough burns away to break the loop...

Does not explain the heat though.  Probably bad connections and/or too thin wire.

[Pumba]

And crappy ACDC AC Isolator too

[Bl4d3]

8 hours ago, Vassen said:

Hi. 
 

How are the panels connected. 3s3p or?

the cable should have a mm rating on it, either 4 or 6 or if you really lucky 10. 
 

where / how are the strings combined as there’s just 1 set of cables in that dB.

I see you also don’t have a set of surge protectors for the panels. 
 

lastly, the isolator looks like a normal ac isolator. You need to use a dc isolator. 

Thanks for your response.
It looks like 3S3P, we peak at 2.8kw at +-120v. Each panel nominal voltage is 40v hence the assumption.

The strings are combined on the roof at the solar panels. We have a single positive and single negative which then comes down from the roof to the isolator switches.

Correct, there appears to be no surge protector, is this a requirement? The electrician was supposed to install it all to 'code'.

I've attached an image of the cable where info is written, I'm not too sure what the thickness is because at one point it marked "6.00" and another point "MM2", I can assure you that the cable is not 2mm, it does appear to be 6mm stranded, the cable is silver in colour and not copper, could this mean that the it is stranded aluminium cable?

 

[Tariq]

installing AC isolaters and NO surge protectors is definitely NOT following SANS regulations, which would, in case of a fire would invalidate an insurance claim

[Paulcupine]

Should that wiring from the panels not go to the fuses FIRST and the isolator SECOND?

 

[Bl4d3]

So just an update.

We had another company come out and correct the install.

All 3 strings are now wired into the DB board (6 wires total), each line is fused and then passed through an isolator. Surge protection was also added on both the solar side and inverter output side.

This fix up cost an additional R12000, the previous installed had the cheek to ask for his old equipment back since we are no longer using it

[Bl4d3]

On 2021/01/27 at 8:33 AM, Blowdart18 said:

One makes me think you might be the installer considering you have been on the forum for 3 years and this is your 3rd post. 

 

Coming out of the block you attack OP, calling him a "-- deleted by moderator---" and that he should let grown-ups sort it out. Clearly you might be the one going about doing stuff the wrong way to be honest, as this forum is used as a platform to help and educate people on these matters and put them in touch with people that can assist. 

 

Also your comment here: "-- deleted by moderator---" - Unfortunately if you want to run a business you should be able to take the punches, regardless if you on holiday or not, it is still your business and decency would dictate you respond to your clients and keep to your word of sticking to an appointment. 

 

What recourse do consumers have when business owners cannot be held accountable, if OPs house burnt down because the installer did not correctly install the equipment what would you say? Even after a year you can still be held accountable for an install if the incorrect equipment was installed.

 

Judging by your response, it would seem that was the response from the installer, sadly I did not see it before it was removed.

I would like to thank everyone for the advise provided.

As for the installer, I intentionally did not name or shame you, I intentionally left out your branding stickers that you stuck on the inverter and the DB board, I removed my 1 star review of your business when you begged me to, I am sorry that you do not see me as a grown up and that we did not have the opportunity to meet, I am actually an incredibly busy person as I handle the international distribution and support in all 49 countries that the company I work for is in. Perhaps you see it like this because I live with my parents, the reasons for this are :
1. I am mostly out of the country for 9 months a year on business trips.
2. My parents are elderly and when I am here, I help them and look after them.

If you would like to discuss this further, you have my cellphone number.

[Pumba]

R12000 to rectify the first installers poor workmanship - wow. You are lucky the house didn't burn down. In this solar game there seem to be many chancers out there.

As they say "Consumer beware!"

[Bl4d3]

On 2021/03/15 at 8:06 PM, Pumba said:

R12000 to rectify the first installers poor workmanship - wow. You are lucky the house didn't burn down. In this solar game there seem to be many chancers out there.

As they say "Consumer beware!"

2 month update

System working well other then an issue with the 1 inverter but that will get sorted later this week.

Cables are no longer hot and fuses are no longer blowing.
Even in autumn, the system is outputting an extra 400w than it previously did in Summer.

I will give credit where credit is due, the original installed installed the panels as best they could given the space, cabling and overall install was also quite neat and tidy.

Edit : After closer inspection, it would seem that the original installer has learnt a lesson from this thread and is now wiring his newer installs correctly.

Edited May 16, 2021 by Bl4d3
Incorrect info