Low Temperature For SWA Cables - Do they exist?! 1

[JohnnyHS]

Hello ladies and gents,

Have had a search online and through suppliers for a SWA cable that can operate at -40 to 70oC. i can find non armoured cable that can do this but not armoured. (may just have to conduit/mechanically protect the non armoured)

it is required for 230/50 2 Amps. 2.5mm2 3 cores.

Any advice? Its for power transmission in Slovakia where it can get that cold!!

Johnny H-S BSc(Hons) MInstMC

Engineers like to solve problems. If there are no problems handily available, they will create their own problems.

 

[waross]

What is SWA cable?
Here are some flavours of Canadian _40 deg. cable.

http://www.texcan.com/products/default.htm

Teck cable, a flexible armoured cable originally designed for use in Canadian mines, has become a key component for the distribution of electricity through a broad range of industrial, commercial and manufacturing facilities. A combination of interlocking flexible armour with two layers of PVC jacket enables a rugged, compact and flexible cable that is resistant to corrosion, water and mechanical abuse. Teck cable has a maximum conductor temperature of 90°C and a low temperature rating of -40°C. It is available in voltage ranges between 600V and 35KV.

http://www.nexans.ca/eservice/Canada-en_CA/navigate_206585/Armoured.html

AC90 (–40°C) XLPE 600 Volts 90°C Low Smoke Zero Halogen
AC90 (–40°C) ISO-BX XLPE 600 Volts 90°C Low Smoke Zero Halogen
ACWU90 (–40°C) XLPE 600 Volts 90°C

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[JohnnyHS]

Thanks Bill, very useful.

The situation is that we will be bending and installing in the UK here - ambient 20oC (in fact a little less - you may be familar with our summers!) - not a problem

Its for when the system is placed on site where the already installed cable is subjected to -40oC ambient.

Most specs i read state bending/install temp which i presume is related to the "brittleness" of the PVC for bending but not of the operation temperature which again these cables state install temps. I am not sure why cable companies dont state operating limits below a level- surely there are some?!

Whilst these cables would do the job my specific scenario may not need the "special" cable (and therefore cost/delivery implications etc) but a cable that can be installed, bent etc in a 20oC ambient here in the UK and then placed in operation in a -40oC max temperature environment

PS Bill SWA is steel wire armour

an example from the UK

http://www.batt.co.uk/products/view/383/BS5467-SWA/PVC-Cable-IEC60502-600/1000V

Johnny H-S BSc(Hons) MInstMC

Engineers like to solve problems. If there are no problems handily available, they will create their own problems.

 

[waross]

Hi JohnnyHS.
We see some cold weather here. Our code prohibits installation of thermoplastic insulated cables and wires when the ambient temperature is low enough that damage to the insulation may result.
We see a lot of -40 Deg C rated cables. This is suitable for installation at cold temperatures, (carefully). If cables are installed during warmer weather the installation may then be subject to cold temperatures as long as the cable is not subject to flexing.
I had an experience doing a small job in the Yukon Territory in the winter.
The feeder was installed during warmer weather but the temperature dropped before the terminations were completed. At about minus 20 F the insulation on the conductors started to crack. Work was suspended immediately. We build a small tent and added a large heater. When the cables and work area were somewhat warmer the few cracks in the insulation were repaired and the terminations were completed. This was not cold weather rated cable. Once installed there were no further issues. The installation was acceptable to the AHJ as long as there was no remaining damage from the installation.
Our code does not specify a temperature, it states words to the effect that thermoplastic insulated cables must not be installed when the ambient temperature is low enough that the insulation may be damaged.
Once installed, the cable must be fastened or supported so that it can not flex if low ambient temperatures are expected.
Hope this helps

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[JohnnyHS]

Yes a great help Bill - thanks. We have proposed the same to our customer. It is a very small amount of cable we are using, hopefully common sense will prevail.

Johnny



Johnny H-S BSc(Hons) MInstMC

Engineers like to solve problems. If there are no problems handily available, they will create their own problems.