Is it safe?

What is it about people with their disregard for the dangers of electricity? A lot of people like to dabble with their home electrical systems. It can save you money, and if you are competent why not. But if you don’t know what you are doing – do yourself a favour and and leave it alone!

There could be a whole variety of problems that might cause what's happening in this picture.  The heater itself could have a problem, perhaps the power outlet has been damaged, or the insulation at the plug might have been damaged.  It is images like this that were on my mind and led me to change the fuses in my new property.

My new property is an older building and the house wiring uses fuses in the meter box rather than circuit breakers. I bought some fuse wire and set about replacing all the power and lighting fuses. Everything was working okay before I started. I just wanted new fuse wire in each fuse. It’s not as odd as it seems.

The fuse wire in most of the fuses seemed okay. The occasional one was discoloured, which is perfectly fine.  But if got so hot to cause a discolouration you have to wonder what was going on. They all got replaced because I had no way of telling for sure that the correct rating fuse wire had been fitted to each fuse. Fuse wire for lights is thinner than that used for the power system. The thickness can give an indication, but you don’t know for sure what’s in there. So, I replaced the lot. Except for the stove and main fuse which generally never blow and ordinary usage wouldn’t affect them.  The only way to be sure of what’s fitted is to replace the fuses with new, correctly rated, fuse wire.

One fuse caught my eye. The fuse wire on one had been replaced with copper wire. How did I know it was copper wire? Because it was very flexible and comprised multiple fine strands twisted together like you would find after stripping the insulation from a piece of speaker wire. What idiot would do such a thing? I don’t know but I suspect it happens a lot.

If you overload the wiring in a correctly wired and correctly fused circuit the fuse will blow.  That's what's meant to happen.  The fuse blows before any damage is caused.  But if fuse wire has been replaced with something else you are removing a safety device, and run the risk of starting a fire.  The example in the picture would be easy to see and smell, but if the fire starts in a wall cavity or in the ceiling you are unlikely to know about it until the blaze is well alight.

I was checking the fuses because of previous experiences. I bought a house in Tasmania many years ago, and just out of curiosity I had a look at the meter box and all the fuses. There was a huge piece of copper wire in one of the fuses. (Huge: think power cable.) It was plainly dangerous.  From that day onward I never trust what other people put into their fuses. When I bought my next house in Canberra I made the same check, and you guessed it, one of the fuses had a piece of copper wire installed. It was a thin piece of wire, but it wasn’t fuse wire. So, it’s no good.

I can just imagine the scenario. Someone loaded up the circuit in the house with too many appliances, or some electrical gadget developed a problem and the fuse blew. And the power went off. This would have happened in the dead of night, or on a Sunday or public holiday when the shops were closed and there was no fuse wire to be found anywhere, and there was a house full of guests. So, what did the numskull do? Grabbed the first bit of scrap copper wire they could lay their hands on and stuff it in the fuse, and think it’s fixed. Wrong! No doubt done with the intention of replacing it next time they went to the shops, but that never happened, because they forgot.

With this experience, I can understand why replacing fuses was considered the work of a qualified electrician. Doing it with the incorrectly rated fuse wire (or with copper wire) can cause a fire. Replacing fuses is also kind of tricky. The ceramic fuse blocks can sometimes be very difficult to get out. Sometimes you have a fight on your hands to pull them out, as they can be difficult grab hold of. They can stick like someone used Loctite, or Araldite, or something to glue them in place. There is also the constant danger of inadvertently touching one of the electrical contacts during the process. Yes, I know, there are switches to shut off the power, but who’s to say the electrician wired the house correctly. Trust nothing. You should even check that the light and power fuses actually go to light and power. Like I said, trust nothing.

I left the card of fuse wire in the meter box for the tenants should they need to replace one on their own. Now that I’m about to rent the property, maybe I should replace all the fuses as a matter of course after each tenant moves out to make sure the correct rating have been fitted.

Don't adopt a "She'll be right" attitude, and forget about it.  Check it.  Fix it. Make it safe.  If you don't trust yourself, call an electrician.  It'll be money well spent.