New board connected to V I R cables

[powervan]

Hi whats the situation on following!
went to wire a bathroom today in old terraced property all looked good new board (last 6 months) full niceic member! certificates not to hand YET! looked in loft to find V I R cables! works out from board new cables run 2 mtrs into joint boxes picking up old cables! as it happens its not a problem for me as found a pvc 6mm left in loft and other end just outside the board)) so can work my stuff from this BUT i would only ever connect to old cable if we were doing a rewire very shortly after!! is this a Good Practice issue or is there a reg that said THOUT SHALL NOT CONNECT TO VIR even if it tests ok?? lighting hasnt cpc but thats not the issue as this has label on the board! diff subject the plumber used a junior hacksaw to cut through a live vir cable that just had no jb on end ASSUMING it was dead( he wont do it again

 

[Knobhead]

VIR if not stressed isn’t a problem, the installation method may be.

We were replacing two Metropolitan Vickers open slate panels with new MCC’s. The panels and cabling were installed in 1932. Samples of the VIR were sent to BASEC to see if it was suitable for continued service. Of the 250+ motors only a dozen or so needed re-cabling. The plant is still running to this day.

Testing the cables the minimum IR wasn’t set at the stupid IET one size fits all 1MΩ. We calculated the minimum insulation resistance by using the proper method where leakage current is not to exceed 1/10,000[SUP]th[/SUP] of the circuit FLC.
To be on the safe side we lowered the maximum leakage to 1/5,000[SUP]th[/SUP] at 2X working voltage. I.E. 1000V Ph→Ph, 500V Ph→E.

You can only go by observation and testing. NOT some myth that VIR will fall apart the moment you look at it.

 

[Engineer54]

VIR if not stressed isn’t a problem, the installation method may be.

We were replacing two Metropolitan Vickers open slate panels with new MCC’s. The panels and cabling were installed in 1932. Samples of the VIR were sent to BASEC to see if it was suitable for continued service. Of the 250+ motors only a dozen or so needed re-cabling. The plant is still running to this day.

Testing the cables the minimum IR wasn’t set at the stupid IET one size fits all 1MΩ. We calculated the minimum insulation resistance by using the proper method where leakage current is not to exceed 1/10,000[SUP]th[/SUP] of the circuit FLC.
To be on the safe side we lowered the maximum leakage to 1/5,000[SUP]th[/SUP] at 2X working voltage. I.E. 1000V Ph→Ph, 500V Ph→E.

You can only go by observation and testing. NOT some myth that VIR will fall apart the moment you look at it.

Well said, that Man....lol!!

 

[rapparee]

We have lots of vulcanised rubber in our factory connected up to fancy flush brushed chrome accessories, management won't pay for a rewire, but will pay to replace light switches, light fittings etc, we make our recommendations get over ruled shrug shoulders and accept management knows best.

 

[Geordie Spark]

We have lots of vulcanised rubber in our factory connected up to fancy flush brushed chrome accessories, management won't pay for a rewire, but will pay to replace light switches, light fittings etc, we make our recommendations get over ruled shrug shoulders and accept management knows best.

Best way ... then you can laugh your wotsits off at them when it all goes to rat****.

 

[PEG]

Me dad has tea maker that has functioned without error for nearly 60 years...it was her birthday today! Happy birthday mum :bow:

 

[moospark]

Me dad has tea maker that has functioned without error for nearly 60 years...it was her birthday today! Happy birthday mum :bow:

So ya Dad's ya Mam?

 

[Geordie Spark]

So ya Dad's ya Mam?

and Bob's his Uncle.