Breaker tripping and rewiring question

[tntdiy]

Hey guys new DIY user here.

I am doing an evening course on Domestic Electrical Installatons but it is on hold now because of Covid. We got through some theory and just started with the fun part when the SHTF.

Now in lockdown, I have time and a project on my hand but it is not going great so far. I have an 8x32' wooden box at home that was used for aquaponics but I was allowed to clean it out and use it as an office.

Made my first change to the electricals which was adding two new double sockets and they seem to work fine but after one off the breakers - one that has the three light fixtures on it keeps tripping since I did that.
So my questions are:

1. I noticed that this breaker can not be reset even when the main breaker is off. Does this mean that breaker itself is broken? Or is it more likely that one of the lights or switches are shorting?
How do I go about checking the breaker and the lights and switches?

2. If the breaker is gone I cannot replace it and it is unlikely I can find somebody to do it due to the lockdown. Can I temporarily hook up the lights with another circuit? The load should not be a problem I think.

3. What does back-feeding mean? (in the context of circuit and junction boxes ) this is independent of my problem but I saw it mention in a few places and didn't find an answer on google.

This a pic of the electrical (sub) panel for the garage and this office box. Bottom left is the breaker in question. Above that, the double one is for the AC unit that's in the box. Another breaker is running the sockets in the box. My guess is that this panel is from the 90ies maybe.

Thank you for any input!

 

[Wilko]

Hi TNT - can I ask are you in T or UK? Have they taught you the safe isolation procedure yet?

If the installation is confirmed to be electrically isolated and an MCB still won’t reset then it’s likely the MCB that’s busted. These old ones do sometimes have an internal mechanical failure that prevents them latching on. This can be confirmed by visual inspection, but only if the installation is safely isolated.

 

[tntdiy]

Hi TNT - can I ask are you in T or UK? Have they taught you the safe isolation procedure yet?

If the installation is confirmed to be electrically isolated and an MCB still won’t reset then it’s likely the MCB that’s busted. These old ones do sometimes have an internal mechanical failure that prevents them latching on. This can be confirmed by visual inspection, but only if the installation is safely isolated.

Hi! I am based in Trinidad now. Thanks for the reply!
No, we had no training on safe isolation yet so all I know that I have to stay away from the panel, it's way over my head. I will have to call a real electrician for that, once the lockdown expires or at least we have some kind of normality.

So my next question is - if you don't mind - that can I take power from the socket circuit for my lights? Is that good practice, at least for temporarily?
In this photo below you can see that the layout of the light switch and the sockets below and I am tempted to just join the light into the working circuit...

 

[Wilko]

Hi - probably not a good idea without fusing down. If you added a fused connection unit with a 3A fuse (instead of 13A) it might be ok.

Click Polar 13A Fused Connection Unit (FCU) with Flex Out (PRW050)

Click Polar 13A FCU With Flex Out (PRW050) . Fast and Free Delivery Available. Trade Quality with Low Prices.

www.electrical2go.co.uk

 

[tntdiy]

I didn't know these things exist! Do you recommend them because the sockets might draw more power than the switch and the lamp can handle? In that case, can I just condemn the sockets for security? I don't plan to use them anyway.

I am trying to simplify things as our lockdown is just starting and I am not sure if a run to an electrical shop would be frowned upon by the authorities and the highest authority, the wife.