Oil filled paper insulated cable

[skatingsparks]

Morning

Has anyone experience with the old (1950's) oil filled paper insulated cables.

A client is redoing a block of flats in stages. He has been told that the main panel is the biggest issue (I disagree but there you go)

Oil filled cables was long before my time. I know they are used in HV but thats not my area. Is it possible to reterminate these things in the short term.

The oil has started to leak from some points which i guess means the effectiveness of the insulation is reduced.

I have suggested we replace them first but someone higher up the food chain (AIA inspector) said the panel is a biggewr problem (it is a big problem but feels like putting cart before the horse)

He will have to replace them but wants the panel done first.

Any advice/direction/suggestions appreciated.

[AndyD]

I wish I could say they're long before my time as well but I was taught how to do wiped lead joints on air and oil pressurised cables as an apprentice. It was a skill I never had a use for in later working life because they were already being replaced with newer generation cables.

Is the cable a pressurised oil fill or is it just oil impregnated? What material is the outer sheath of the cable? Can you maybe post a few pics of the cable breakout and terminations?

If it's a pressurised oil cable then leaks won't necessarily mean IR values will be compromised. At the origin of the cable there will be a pressurised oil supply and usually an alarm system that would alert if the pressure or oil reservior level became too low. Even with unpressurised oil impregnated cables the insulation would only usually be problematic if there were underground oil leaks that subsuquently suffered prolonged soaking by water or flooding.

Oil and paper insulated cables were used across all applications from ELV up to HV. Retermination could be possible but it would require finding someone with appropriate experience and tools.

[skatingsparks]

Hi Andy

They are not pressurised cables. We manage dto convince teh client just to change.
If you are going to spend big bucks on a panel why would you keep old cable which may of may not survice the moving/retermination process.

After doing another site visit the ammount of other problems is 'impressive'

VIR cable on the risers and the people who worked on the many DB boards really had no idea what they were doing.

Found a DB board in the downstair kids school with 4 VIR socket circuits jammed into one breaker, no earth leakage and to top it off they used 1.5mm as the bridging cable.

Think he's going to have to pretty much redo the whole building eventually. It hasn't got much left to give.

[AndyD]

Yeah, almost certainly better to replace than trying to divert or reterminate, it will definately be cheaper to replace it in the long run.

Same with VIR. The problem is that it usually IR tests okay before it's disturbed but as soon as you start working with it or even near it the insulation has degraded so much that it just falls off. I've been caught out in the past so now I don't offer any options with VIR other than replacement.

[GCE]

When I come across VIR wiring I use section 5.1 note 2 - Manufacturers instructions may require more stringent requirements .

VIR wiring was manufactured with a 25 year life span , they stop manufacturing the wiring over 30 years ago , I say under correction.

[ians]

Now you okes are giving away your age ... when we were appy's we had to do joints with these cables.

How many of you got lead in your face from dropping water in the pot?

[AndyD]

I've heard that 25 year or 30 year VIR lifespan mentioned before but I've never seen it stated on anything official or been able to officially confirm it. Have you got an original manufacturers document with it stated? I'd be grateful for a copy if you have...

[GCE]

Hi Andy
I don't have any documentation on VIR , Need to have a look through some of the old books and regulations I have to see if I find anything

[skatingsparks]

The VIR in this building is hanging by threads.... Literally.