Fire in junction box

[Vicario]

In today's Times there is an article about houses built using bales of straw. One was destroyed due to a junction box that caught fire. I was wondering how this could happen and what a (conventionally built) homeowner could to reduce the risk. The reason I ask is that I know that over the years my house has acquired some of these after adding sockets etc. All done by qualified electricians of course.

 

[winston1]

Best to avoid junction boxes. Additional sockets are best taken from an existing one.

 

[AndyPRK]

the screws get loose.

you could check the screws are tight every 10 years

 

[John D v2.0]

Nowadays there are so many better types of connector that screw junction boxes are less useful.
The only benefit i can see is they are very flexible on terms on number and thickness of conductors in the terminals.
If you're doing connections outside of an accessory I'd always recommend some kind of maintenance free connector.

 

[Bob49]

the screws get loose.

you could check the screws are tight every 10 years

HI, What happens during an electrical inspection, is every accessory and junction boxed opened and checked? Or do they do a resistance test? There must be junction boxes under laminate flooring, sockets behind kitchen units and fitted wardrobes, etc.

Bob

 

[crystal ball]

HI, What happens during an electrical inspection, is every accessory and junction boxed opened and checked? Or do they do a resistance test? There must be junction boxes under laminate flooring, sockets behind kitchen units and fitted wardrobes, etc.

Bob

Depends on the agreed limitations, one of the standard ones is that floorboards will not be lifted

 

[Bob49]

Depends on the agreed limitations, one of the standard ones is that floorboards will not be lifted

Oh I see, if you do a continuity test can you tell from the resistance reading that connectors are maybe loose? Or is it inconclusive?

 

[crystal ball]

It might show up, I have picked up loose connections on ELI tests before now

 

[jj4091]

the screws get loose.

Why should the screws get loose in a JB but not socket or other fitting, or is it more the fact that they are often an inaccessible joint that is really the potential problem.
Has any electrician on here had a call from a customer to check the tightness of the screws in their fittings.

 

[crystal ball]

Well I had a call to check all the connections in a house once as the new owner had experienced a minor conflagration due to loose connections in their previous property

 

[John D v2.0]

Why should the screws get loose in a JB but not socket or other fitting, or is it more the fact that they are often an inaccessible joint that is really the potential problem

It's the inaccessible thing that makes them a problem, but they can and do come loose elsewhere, especially if they carry a decent current.

 

[AndyPRK]

You can see from resistance checks.

L and N should match. If they don’t something is loose. It’s just finding it.

CPC is higher resistance as it’s thinner.