Single core cable

[OldGoldy]

There is no trunking.

 

But suppose it still could be done this way.

 

No trunking?

 

You haven't got wires/cables within any polystyrene insulation, have you?

[leeco]

No trunking?

 

You haven't got wires/cables within any polystyrene insulation, have you?

 

Well not polystyrene but rockwool but this cable calculator Suggested a Min of 1.5mm2 for the cable in a enclosed thermal wall for the max load I can get on a 25m lenght and I have used 2.5mm2.

 

http://www.bbowner.co.uk/volt-drop-cable-size-calculator.html

[OldGoldy]

Well not polystyrene but rockwool but this cable calculator Suggested a Min of 1.5mm2 for the cable in a enclosed thermal wall for the max load I can get on a 25m lenght and I have used 2.5mm2.

 

http://www.bbowner.co.uk/volt-drop-cable-size-calculator.html

Can't comment on ratings/distance, was just concerned 'no trunkin'+ polystyrene = poor(cable) insulation/safety.

[leeco]

Can't comment on ratings/distance, was just concerned 'no trunkin'+ polystyrene = poor(cable) insulation/safety.

 

 

Cables in insulation derates them by 50% and from what I learned at college 2.5mm2 twin and earth can take 32amps. I have a 2500w inverter so that would be 2500w / 240v = 10.41 amps and I can't see me ever using the full 2500w on the boat so how is it unsafe?

[Gazboatman]

Cables in insulation derates them by 50% and from what I learned at college 2.5mm2 twin and earth can take 32amps. I have a 2500w inverter so that would be 2500w / 240v = 10.41 amps and I can't see me ever using the full 2500w on the boat so how is it unsafe?

He's not saying it is, is he?

 

Think he was refering to if it was being installed in or around Kingspan or polystyrene..

[leeco]

He's not saying it is, is he?

 

Think he was refering to if it was being installed in or around Kingspan or polystyrene..

 

I don't know but who would insulate with polystyrene anyway. Nothing wrong with kingspan.

[Grace and Favour]

I don't know but who would insulate with polystyrene anyway. Nothing wrong with kingspan.

 

FYI, Boats have, in gthe past, been insulated with polystyrene and polystyrene derivatives.

 

It has since been discovered that where any electrical cabling comes into contact with polystyrene, the insulation on the cabling can be seriously degraded - - which is not good.

 

Hence the cables would need to be fully enclosed in trunking when polystyrene is present

Edited March 6, 2012 by Grace & Favour

[leeco]

FYI, Boats have, in gthe past, been insulated with polystyrene and polystyrene derivatives.

 

It has since been discovered that where any electrical cabling comes into contact with polystyrene, the insulation on the cabling can be seriously degraded - - which is not good.

 

Hence the cables would need to be fully enclosed in trunking when polystyrene is present

 

 

Ok and I could see why as polystyrene is very flammable and can't be very good at insulating anyway. This boat had some in the walls when we striped it out. In the roof it had it all over and was about 2mm thick .

[Grace and Favour]

Ok and I could see why as polystyrene is very flammable and can't be very good at insulating anyway. This boat had some in the walls when we striped it out. In the roof it had it all over and was about 2mm thick .

 

In it's day polystyrene was one of the best insulation materials commonly available - - - which is why it was used

It wasn't long ago that houses had polystyrene insulation too, you know

[leeco]

In it's day polystyrene was one of the best insulation materials commonly available - - - which is why it was used

It wasn't long ago that houses had polystyrene insulation too, you know

 

Yes I can remember been a kid playing on building sites making boats out of packs of the stuff.

[ChrisPy]

I don't know but who would insulate with polystyrene anyway. Nothing wrong with kingspan.

Kingspan is polystyrene, e.g. Kingspan Styrozone.

 

Ok and I could see why as polystyrene is very flammable and can't be very good at insulating anyway. This boat had some in the walls when we striped it out. In the roof it had it all over and was about 2mm thick .

25mm of polystyrene provides adequate insulation. 2mm was used e.g for ceiling tiles - the only insulation it provides (maybe) is a reduction in condensation when it is fitted on the surface (e.g. on ceilings). Same would apply to any insulation material.

[wonderdust]

Depends on what Kingspan product you purchase.

Edited March 6, 2012 by wonderdust