Fuse blowing constantly.

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maoriboy

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#249502 14-May-2019 12:04

I have a fuse that is has only recently started blowing, sometimes more than once a day. As far as I can see it only affects the lighting for one side of the house (2 bedrooms, hallway, toilet and bathroom) so there shouldn't be a big load on it. It does not affect the wall plugs at all. It uses a 5amp fuse wire but did not make a difference when I went up to 10amp. As we have not made any changes or alterations, this is somewhat perplexing. Any suggestions as to what I should look at, or would it be best to just get an electrician in to take a look?

Thanks

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#2236587 14-May-2019 12:15

Is there a light on that circuit that is no longer working?

A blowing fuse suggests a short circuit somewhere - could be a blown bulb?

wellygary

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#2236589 14-May-2019 12:19

The fact that you are changing honest to god, old fashion fuses, with actual fusewire, implies its a reasonably old house (with wiring to match)

My first suspicion would be a connection in one of the light fittings, a wire may have corroded/come loose and it might be shorting out the circuit..

If you are not comfortable doing some fault finding yourself, then call a Sparky, - but what ever you do be careful there is a serious possibility that you could have loose live wires somewhere on that circuit (although you state it is a light circuit, so at least they are high and out of the way)

Rikkitic

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#2236590 14-May-2019 12:20

That definitely should not be happening. It sounds like an intermittent short. I would get an electrician. Don't increase the fuse size. That is dangerous.

Likely causes: Water coming into the house and reaching a light fitting (do you have any leaks?) or ants. If you have wire fuses, you also have older wiring. What kind of light bulbs are you using? Modern CFL or LED contain components that can go bad. There could be other things as well. An electrician should look at it.

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muppet

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#2236598 14-May-2019 12:24

Replace the fuse with a nail*.

If this fuse blows, get an electrician (if you house hasn't burnt down)

* don't really do this please. Ring an electrician and get them to investigate.

maoriboy

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#2236600 14-May-2019 12:31

wellygary:

The fact that you are changing honest to god, old fashion fuses, with actual fusewire, implies its a reasonably old house (with wiring to match)

My first suspicion would be a connection in one of the light fittings, a wire may have corroded/come loose and it might be shorting out the circuit..

If you are not comfortable doing some fault finding yourself, then call a Sparky, - but what ever you do be careful there is a serious possibility that you could have loose live wires somewhere....

Thanks @wellygary, a 1960's build home and yeah my first suspicion is a loose wire or something along those lines. Definitely not that comfortable with dealing with electrical stuff so will be looking at getting a sparkie in asap

djtOtago

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#2236618 14-May-2019 12:55

If it still has the original wiring from the 60s, it is likely it's the black rubber insulated cable or even possibly the older cables running in metal conduit.
Over time the insulation these types of cables use is known to break down, allowing "shorts" to occur. The only fix is to replace the wiring.

PhantomNVD

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#2236677 14-May-2019 13:24

Yes, I had wired that literally crumbled to bits when I reno’d a 1950s batch a few years back. These were the hot water and stove wires too, so you’re likely looking at a full or partial rewrite, as that stuff is really dangerous to leave (even if the sparkle says they can ‘fix’ it, get them to rub some in their hands and see it’s not crumbling)

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Aredwood

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#2236685 14-May-2019 13:39

Switch off / unplug everything in your house. With the offending fuse removed, check that the electricity meter has completely stopped. Then reinstall the fuse with new fuse wire. Does the meter start showing some power usage?

Will the fuse blow even when all of the lights are off? Otherwise, try and narrow down which light causes it to blow.

Double check that all power points are still working. As occasionally power sockets do end up getting connected to lighting circuits. Also things like heated towel rails, extractor fans, security alarm systems. And those shaver sockets in bathrooms. Which people will sometimes replace with normal power points and still leave them connected to the lighting circuits.

Might also be a rat that has eaten the insulation on the wires somewhere.

Had a similar problem happen myself. Except that the fuse would blow as soon as I turned on 1 particular light. It was a twin fluro tube light, and a tiny interference suppression capacitor had failed.

josephhinvest

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#2236690 14-May-2019 13:56

muppet:
Replace the fuse with a nail*.

If this fuse blows, get an electrician (if you house hasn't burnt down)

* don't really do this please. Ring an electrician and get them to investigate.

I realise this is a joke :)

That said, on Easter Sunday we just about lost our house. Possibly an overstatement but not by much. A short circuit in the hot water heater supply cable/power point caught fire. The fuse didn’t blow because the previous owner of the house had replaced the fuse wire with solid copper wire. Was a pretty close call, and lucky we were home to catch it.

To OP: fuses blow for a reason. Each time you reinstate the fuse, the short circuit is given another chance to fail catastrophically. Please get a sparky in to look at it.

Cheers,
Joseph

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#2236695 14-May-2019 14:02

Speedtest 2019-10-14

jamesrt

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#2236707 14-May-2019 14:22

Just in order to tell the story..

My first NZ house was a late 1960s built house, that the original owner extended by adding a new room for the master bedroom (early 70s, I think); as part of this process they created a built-in wardrobe.

Apparently in the finishing stages of the whole thing, they installed the shelves into the wardrobe, and in the process drove a nail right through the power cabling for the lights - but didn't notice because there was no visible sign.

Fast forward to mid 2000's, and we noticed one night that the dual-switched bedside light wouldn't turn off; when I tried to do, the light just went dimmer, and I could hear a nasty crackling noise...

So, pulled the fuse, and got a sparky in - he pulled about 10cm of very charred looking wire from the wall behind that shelf.

Apparently the nail had FINALLY (after an unknown number of years) worn its way through the insulation and caused a short.

House would certainly have burnt down if no-one had been home at the time...

(and FYI, it was white insulation on the outside of the cable, just for a wiring timeframe reference check)

sqishy

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#2236776 14-May-2019 17:09

A couple Q's is the fuse blowing even with all the lights off? I assume that when working the lights do actually all come on?

gregmcc

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#2236789 14-May-2019 17:16

Given the age of the house, it will be 1 of 2 things, failed insulation on rubber insulated wiring or a rodent chewed wiring.

In both cases it would be in your best interest to have the rest of the house wiring checked out as rodents don't just chew in 1 spot and if the old rubber wiring is failing then the whole house wiring is failing.

Do let us know what you eventually find - a picture would be good!

sparkz25

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#2236820 14-May-2019 18:44

Its probably wired in VIR or wood casing if it's that old and should be turned off and call a sparky!

Bung

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#2236835 14-May-2019 19:33

djtOtago:
If it still has the original wiring from the 60s, it is likely it's the black rubber insulated cable or even possibly the older cables running in metal conduit.
Over time the insulation these types of cables use is known to break down, allowing "shorts" to occur. The only fix is to replace the wiring.

Not very likely. The BRANZ website gives 1940-50s as the era for TRS with plastic TPS coming in the 60's. I remember an electrician rewiring our family home with TPS some time before 1965.

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