Fixing pinched light cable

[DetlefSchmitz]

I would bet that this isn't the problem. If it were me - and I feel competent to do this - I would make some measurements of that circuit at the CU to see which wires were shorted, if any. I don't think I'd cut out bits of wire at random.

I mean there is no way this pinched cable is a short from L to N. At most it has to be L to E. This could be confirmed without cutting wires.

 

[Tegid Owen]

I would bet that this isn't the problem. If it were me - and I feel competent to do this - I would make some measurements of that circuit at the CU to see which wires were shorted, if any. I don't think I'd cut out bits of wire at random.

I mean there is no way this pinched cable is a short from L to N. At most it has to be L to E. This could be confirmed without cutting wires.

Ok thanks. How do I find out if live and earth are touching without cutting the wire?

 

[terryplumb]

You shouldn't assume anything. And before attempting to cut that cable,if that's what you intend, you should turn off the power to every circuit at the main switch.
What testing instruments do you have ?

 

[DetlefSchmitz]

I suppose I should say that if you don't know I probably shouldn't encourage you. It is still probably a bad idea to cut wires in the first instance, just to locate the issue. So maybe calling an electrician would be best in the long run. A lot depends on your competence (in this area).

 

[Tegid Owen]

I suppose I should say that if you don't know I probably shouldn't encourage you. It is still probably a bad idea to cut wires in the first instance, just to locate the issue. So maybe calling an electrician would be best in the long run. A lot depends on your competence (in this area).

Ok. Yes good idea. Thank you for your help

 

[Harry Bloomfield]

I was up in the attic walking around at the time. The light had been on for a good 15 minutes. I wasn't anywhere near any switches or cables. Only the ones under the flooring

The crushed cable is very unlikely to be the cause, or need repairing, unless it is resting on a nail or screw. You need to look elsewhere for the cause, which will most likely be below the point you were standing upon, when the trip occurred. Lift the flooring in that area, and look for potential problems there.

 

[SUNRAY]

Personally I'd suggest tracing that cable, disconnect both ends and see if it allows you to reset the breaker. As mentioned in post #5

 

[JohnD]

The cable you show does not look very deformed. I will be surpised if that's where the fault is. A nail through a cable is more likely, or a squashed cable in a hot position, e.g. on a pipe or lamp, that softens the insulation.

 

[JohnD]

It is bad practice to have a 13 a socket on a lighting circuit

No it isn't.

 

[bernardgreen]

Winston1 has an opinion that

It is bad practice to have a 13 a socket on a lighting circuit,

This is his opinion.

A 13 amp socket on a lighting circuit is acceptable in the regulations and is often necessary where the device/appliance has an integral 13 amp plug.

 

[bernardgreen]

Why. Engage brain before posting. Such a device/appliance can be plugged into a 13 amp socket correctly wired on to the correct circuit.

If the appliance is a lamp with a power supply module designed to plug into a 13 amp socket then ( engage brain ) the lighting circuit may be the correct circuit for supplying the lamp,

Engage brain even further and ( try to ) consider what happens if a power supply module designed to plug into a 13 amp socket overheats, goes into meltdown and the supply to the socket is ( following your (b)advice ) from a 32 Amp MCB.....Compare the damage done before a 32 Amp MCB trips with the damage done before a 6 Amp MCB trips.

Many power supply modules designed to plug into a 13 amp socket do not have effective fusing built in to them and do pose a significant risk of fire if they become faulty,

 

[bernardgreen]

Shouldn’t happen

But it does,

Should be protected

6 Amp protection is generally better than 32 Amp protection when it comes to damage limitation

Don’t buy non conformist junk

Even conformist items can fail.

 

[winston1]

.

 

[FrodoOne]

Ah, the wonders of the UK domestic electrical distribution system!

This "problem" (of "winston1") was actually "solved", before it happened, in Australia/New Zealand - circa 1934

It was then "decreed" in Australia that the "Power" Socket-Outlet be of a "particular design", rated to carry 10 A and be installed on circuits rated to carry 16 A, when the circuits were "protected" by Fuses of that rating.
When Circuit Breakers replaced Fuses, the "rating" of the same "power" circuits was increased to 20 A.

Lighting circuits were specified as to be "protected" by 8 A fuses (not 6 A), increased to 10 A when protected by Circuit Breakers.

Hence, a standard Australian/NZ 10 A socket outlet may now be connected to a "Power" Circuit (with an associated "switch") or to a "Lighting" Circuit - without any closely assisted "Switch", but with the switch associated with the "Lighting Function".

"Australian/NZ" Light Switches are rated at 10 A.
This is because "Lighting Circuits" in Australia/NZ are rated at 10 A (not 6 A) - using 1 or 1.5 mm² conductors.
Hence it is quite permissible and often done to use a "standard" 10 A surface-mounted Sacket-Outlet (without any extra individual switch) to supply a light fixture in a roof-space.

See https://www.sparkydirect.com.au/p/Clipsal-413-Surface-Socket-Back-Wired-413WE

 

[EFLImpudence]

Does Australia/NZ define a "power" circuit and/or a "lighting" circuit?

Are you forgetting that UK "lighting" circuits utilise 16A cable (fashion nowadays for using 20A cable) therefore could be the same as yours (or European).

The fact that UK accessories are 6A is as irrelevant as yours being 10A.