Vir cabling allowed for fuseboard change ??

[Electric Scott]

Hello all, I'm new to this but seeking some advice.
Just done an eicr, all lighting is white 1980s cabling, as is MOST of the power cabling. However, there are random 2-
3 sockets in old vir wiring, this is generally a no no to deal with, however, the consumer needs upgrading. Can I do this and sign off knowing that vir cabling is within the installation ??
Any advice is appreciated

 

[telectrix]

if the cables are in good cobdition with no disintegrated insulation, OK, but put a note on the cert.

 

[MJPD29]

Have you done any IR testing? If so what are the results? It’s well past its service life

 

[ipf]

Have you done any IR testing? If so what are the results? It’s well past its service life

If it's not taken much, load wise, and is undisturbed, it could be in good enough condition. The problems occur, because of age, with heavy use.
Problems could occur if disturbing, even for testing, especially at connection points.

 

[MJPD29]

If it's not taken much, load wise, and is undisturbed, it could be in good enough condition. The problems occur, because of age, with heavy use.
Problems could occur if

Strangely I have a 3 metre length under my stairs from when the house was rewired (buckle clips were too good quality to remove) and it’s in perfect condition. Other end of the same cable was completely falling apart.

 

[timhoward]

As above, the simple act of pulling an old CU over it and feeding it into a new one and forming it to where it needs to go can finish it off.
If it IR tests ok then you may get away with carefully feeding a new CU over it and wago’ing pvc onto it for final connection. I’ve done this a couple of times in circumstances where an immediate rewire wasn’t possible.

 

[Electric Scott]

As above, the simple act of pulling an old CU over it and feeding it into a new one and forming it to where it needs to go can finish it off.
If it IR tests ok then you may get away with carefully feeding a new CU over it and wago’ing pvc onto it for final connection. I’ve done this a couple of times in circumstances where an immediate rewire wasn’t possible.

Thankyou all for the comments. I don't think I was too clear - there is NO vir cables at the fuseboard, just white twin and earths, continuity tests out ok, didn't do an IR test in all honesty, the vir cables are just at a couple of sockets, no idea where they go or what they connect into. I did get a good earth loop reading on the vir sockets

 

[timhoward]

Friendly advice, before you start at least do a global IR L+N together to CPC bar at 250v.

Without it you have no idea if things are safe.
Also if adding RcD protection you want to know that earth leakage is within tolerable limits.

 

[Electric Scott]

Friendly advice, before you start at least do a global IR L+N together to CPC bar at 250v.

Without it you have no idea if things are safe.
Also if adding RcD protection you want to know that earth leakage is within tolerable limits.

Thankyou for the advice and will take that on board moving forward. There is currently an rcd main switch which trips within required times, so no issue there. The circuits are doubled up and I need to re run a 6mm for cooker so upgrading the board was the best option. It's just this vir in a socket that concerns me, as by changing the board, you re signing off the install

 

[pc1966]

Friendly advice, before you start at least do a global IR L+N together to CPC bar at 250v.

Definitely good advice!

250V means it should not complain about any surge protection built in to stuff that is still connected, and if you get a sensibly good global value you have far less to worry about.

Of course if it fails you do have an issue, but sometimes that is down to an RCD socket outlet or similar (that was designed to trip on open-neutral or reverse polarity fault, so it has a sense resistor to E).

 

[MJPD29]

Thankyou for the advice and will take that on board moving forward. There is currently an rcd main switch which trips within required times, so no issue there. The circuits are doubled up and I need to re run a 6mm for cooker so upgrading the board was the best option. It's just this vir in a socket that concerns me, as by changing the board, you re signing off the install

But what are your IR results on this VIR cable? That’s really the main issue, you can’t sign anything off unless you have done your testing.

 

[freddo]

But what are your IR results on this VIR cable? That’s really the main issue, you can’t sign anything off unless you have done your testing.

The problem with rubber is it is an awesome electrical insulator, even when it has gone gooey or super dry and crumbly.

 

[davesparks]

Don't put all your faith in an IR test. You need to thoroughly inspect the cable and it's terminations before deciding whether or not to proceed with this.

That cable has well exceeded it's service life and you should really be looking at options to replace it.

As it is VIR it will be using the steel conduit as the CPC so you also need to thoroughly inspect and test that.

 

[nicebutdim]

Don't put all your faith in an IR test. You need to thoroughly inspect the cable and it's terminations before deciding whether or not to proceed with this.

I'd contend that any visual inspection would need to cover 100% of the cable.

I've seen rubber cable that has been perfectly supple and in excellent condition along the majority of its length, but with very small sections crumbling. In the OP's shoes I'd be absolutely certain about where I stood, before signing this off.

 

[Rockingit]

There’s also a commercial aspect to this too - assuming that it visually looks OK and you get an IR above 2Mohms, technically you’re OK to proceed however the client is going to be less than impressed when it fails in a years time and Sparky No.2 is giving you a right bashing for not having changed it ‘when it made sense’. I’d talk to the client and explain the overall situation and best practice would be to replace it regardless of if it still works today or not.

 

[7029 dave]

VIR is well over its service life, and IMO the priority is to get that replaced first.

 

[MJPD29]

It really should be replaced. Connecting it is taking a risk as you won’t be able to visually inspect 100% of the cable in most cases. Personally I would not reconnect and if client was objecting I’d prefer to walk away.

 

[davesparks]

I'd contend that any visual inspection would need to cover 100% of the cable.

That's impossible with VIR as its in conduit, and if it isn't in conduit then that a whole other problem as it is single insulated cable.

Obviously if it was an insulated and sheathed rubber cable like TRS or CTS then that may be possible to do 100% inspection.

 

[nicebutdim]

That's impossible with VIR as its in conduit, and if it isn't in conduit then that a whole other problem as it is single insulated cable.

Obviously if it was an insulated and sheathed rubber cable like TRS or CTS then that may be possible to do 100% inspection.

You raise a valid point, but I'd worked on the assumption that VIR is being used as a general term for rubber cable as other posts in this thread have done.

Somewhere in the installation the rubber cables have been joined to T&E and these joints haven't been found, much less inspected.

Given the age and type of cable under discussion, along with 'known unknowns', I don't think anything should be assumed about condition.

 

[brianmoooore]

VIR stands for Vulcanised Indian Rubber and no more indicates the type of cable than PVC does.

 

[pc1966]

That's impossible with VIR as its in conduit, and if it isn't in conduit then that a whole other problem as it is single insulated cable.

If it was VIR in metal conduit I would be far less worried as fire risk fairly well contained.

It is the open stuff that would worry me, even if the CU change adds RCD protection that might catch faults that are enough to start a fire but not so high as to trip a MCB fast.

 

[7029 dave]

This type of cable has been installed domestically as far back as the early 1900's, so well over 100years old its done its job.

 

[nicebutdim]

This type of cable has been installed domestically as far back as the early 1900's, so well over 100years old its done its job.

Most of the rubber cable I've encountered dates back to the 1950s, but that 50 years makes little difference when long past its serviceable life.