spiral wrap

[crossley]

Doing a few wiring alterations today,and have used spiral wrap for convenience behind some panels next to polystyrene insulation. I can't see any issue with this, but do bss have another view?

[W+T]

not that i can think of, aslong as it is supported, i am sure the BSS does not concern on insulation used. i will have a look.

 

can not see much

 

http://www.boatsafetyscheme.org/media/268789/ecp-private-boats-ed3_rev2_apr2015_public_final.pdf

Edited June 19, 2016 by W+T

[Alan de Enfield]

Doing a few wiring alterations today,and have used spiral wrap for convenience behind some panels next to polystyrene insulation. I can't see any issue with this, but do bss have another view?

 

It will be OK as long as the spiral-wrap is polyethylene and not PVC. and, as long as the Polystyrene does not touch any of the PVC cables / wires in the gaps of the spiral wrap.

 

Polystyrene 'eats' PVC cables.

The plasticisers in the PVC 'migrate' away from the polystyrene leaving a brittle coating that can vibrate and fall away leaving the copper conductors to short out.

 

There is a 'non-migratory' PVC that can be used but its unlikely you will find it on standard 'boat' wiring.

 

See pics

 

 

Edited June 19, 2016 by Alan de Enfield

[W+T]

not that i can think of, aslong as it is supported, i am sure the BSS does not concern on insulation used. i will have a look.

 

can not see much

 

http://www.boatsafetyscheme.org/media/268789/ecp-private-boats-ed3_rev2_apr2015_public_final.pdf

 

edit again, but how will the examiner see the modification if behind panels, they dont remove things to check?

[crossley]

It's polyethylene. Just checked.

Is that twin&earth in the pics? Looks like it.

I've got a box of plastic grommets that have fused themselves to the plastic box they've been there that long.

[system 4-50]

Remember to ensure that the direction of the spirals is in the opposite sense for each side of the boat, otherwise the boat will have a very slight tendency to corkscrew, a bit like prop-walk.

[cuthound]

Polyethylene spiral wrap is widely used in the electrical panel building industry. The BSS is silent on it, so if I were you I would go ahead and use it.

[trackman]

We used an independent surveyor to check our boat fit out. He got into a spat with our boat builder about the fire resistance of this stuff.

 

He wanted a fireproof version used, saying that was what the RCD required, the builder had always used fire resistant and couldn't source fire proof. The builder had used the same stuff in lots of boats and no other surveyor had queried it.

 

The difference between fireproof and fire resistant appeared to be that the first won't burn at all, the second will burn, but only if it's held in a flame. We decided to go with what the builder was using!

 

It's never been queried since and the boat is now 10 years old. It has passed its boat safety checks first time every four years.

[David Mack]

He wanted a fireproof version used, saying that was what the RCD required, the builder had always used fire resistant and couldn't source fire proof. The builder had used the same stuff in lots of boats and no other surveyor had queried it.

And was the cable it was wrapped around fireproof, or merely fire resistant?

 

And what would be the problem if the spiral wrap (as opposed to the cable) did catch fire?

[Alan de Enfield]

And was the cable it was wrapped around fireproof, or merely fire resistant?

 

And what would be the problem if the spiral wrap (as opposed to the cable) did catch fire?

 

I think the problem would be insignificant compared to the surrounding polystyrene burning

 

Aside from its use in WMDs (add a bit of petrol, a squirt of WD40, squish it around a bit and you have a home made 'napalm') it contains lots of 'nasties' - when it burns it gives of styrene gas which has serious affects on the human nervous system, & it generally releases lots of Carbon Monoxide as it rarely has a complete 'burn' (as can be seen by the clouds of black smoke it gives off)

 

Many people are aware that chloro-fluoro hydrocarbons were eliminated from expanded polystyrene a decade ago, but when talking about 'elderly' narrowboats there is very high percentage chance that their polystyrene will be the 'old recipe' and be rich in Chloro-Flouro hydrocarbons - this in addition the Styrene etc etc.