Fire Performance Cable Joints - London Underground Standards - XLPE/SWA 600/1000V

Fire Performance Cable JointsFire Performance Cable Joints

 

Fire performance aspects of SPS 600/1000 volt heat shrink cable joints for XLPE/SWA/LSOH sheathed cables 

Cable Joint Material Description
Using 4 core 30sqmm SWA cable which was known to be compliant with the requirements of London Underground Standards 2-01001-002 "Fire Safety Performance of Materials" and E4156, the cable standard, a cable joint assembly was produced by SPS, an adhesived lined heat shrinkable tube, was used as the main bonding component within the cable joint assembly. A flame retardant silicone layer upon as glass fibre sleeve was provided as an outermost fire barrier protection tube or "over-sock". This assembly was produced as Part Number SPA NH 240-300-4.

Pictured: Fire Performance Cable Joints - London Underground Standards - XLPE/SWA 600/1000V

Fire Performance Cable Joints - London Underground Standards - XLPE/SWA 600/1000V
 

Cable Joint Fire Performance

Fire performance requirements are given in London Uderground Engineering Standard 2-01001-002, ref. Table 2, Test programme for cables, stations and tunnels. This standard relates to the following parameters :

  • Combustibility/flammability (BS EN ISO 4589-2 : 1996 : Part 3 : and BS EN ISO 4589-2 : 1996 : Part 2)
  • Smoke emission (based upon BS EN 50268 : 2000)
  • Toxic fume emission


Materials which are compliant with the appropriate parts of this standard can be used in below ground locations and, where applicable, in rolling stock.

Cable Joints Technical Evaluation

Smoke emission was evaluated by ad-hoc tests based upon test principles given in BS EN 50268 : 2000, comparing requirements with the equivalent cable diameter. Tests were carried out in two positions, at the the middle of the cable joint over-sock and at the middle of interface between cable and joint ends. Taking into account general and specific visibility distances with respect to smoke emission, the assembly was found to be compliant with the requirements of the standard. Flammability temperature index and oxygen index measurements were conducted on the heat shrinkable tube sheath and oversock and were compliant with the standard.

A toxic fume emission evaluation completed the assessment and confirming complete compliance with London Underground Standard 2-01001-002.

Adobe Fire Performance Cable Joints - London Underground Standards - XLPE-SWA 600-1000V

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