I blew the main fuse in my flat :-o

Posted 5th Jun 2023

So my question is, why didn't the fuse on the circuit that caused the main fuse to blow stop the main fuse from blowing as well?
Whoever installed the wiring in the first place put two live wires in instead of a live and a neutral.
I didn't check properly that the circuit was not live and the two wires touched, boooom, blew that fuse and the main fuse, lucky I had a spare.

11 Comments

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5th Jun
2 lives touching wouldnt blow anything.

Step away and get someone who knows what they are doing in.
5th Jun
A neutral to earth, however, would if you have MCBs or RCBOs

As above, get someone who knows what they're doing, especially as it would appear you have an ancient board if you require spare fuses?
5th Jun
Because the short was clearly big enough to take both out.
As mentioned above, get someone who knows what they're doing in to sort this.
5th Jun
Red to Black and blew to bits if you don't know what you are doing get someone that does, For me personally it's just not worth risking your life or risk starting a fire for anything more than Changing a bulb or a plug fuse
5th Jun
Defo heed everyone else's sensible advice and engage a qualified electrical engineer, no point risking your life (or those of others) for the sake of a few quid...
Author
6th Jun
It was an accidental touching of wires, I wasn't being careful enough, it's simple enough to connect three wires.

The previous box it didn't make a difference which way around the wires were connected, the appliance was always on. Now it's a switched box I can turn the appliance off at the wall.
6th Jun
Box? What sort of box? Currently I'm guessing you might possibly be talking about replacing an unswitched Fused Connection Unit?

You need to understand the basics before messing with mains, including how to test and to 100% confirm that the circuit is dead first. Read a few DIY guides at least before messing with 240 volts.
6th Jun
Where are the 2 live wires? At the board or inside a switch or a fitting?
Author
6th Jun
Inside a closed box, like the one Melted mentioned above.
6th Jun
We had that happen when I was away on business - wife was at home with the baby and no power in the entire house. She called out national power in the end and the diagnosed the main feed fuse - the guy was super helpful to her and worked out the circuit and isolated it so the main fuse.

We got an electrician in and it turned out there was a plug hidden behind a kitchen cabinet that was causing a cable to burn out in the wall