These cables, to a BBC specification but updated to low fire hazard (LSOH) standards, have single solid conductors, twisted in pairs and overall foil screens with drain wire. They are suitable for permanent installations where screens are terminated on a bus arrangement, such as jackfields and IDC type blocks. They have a relatively low impedance (they were designed before digital audio was invented) and are not suitable for digital audio circuits.
Technical Specification:
| BBC specification: |
PSN10/3M (KSM-LFH5), PSN20/4M (KSM-LFH10), PSN40/2M (KSM-LFH20), PSN50/3 (KSM-LFH25), modified to low fire hazard design (LSOH) |
| Construction: |
Twisted to form pairs, than laid-up with overall Melinex tape |
| Voltage rating: |
750V DC |
| Conductors: |
1/0.5mm (0.2mm²) tinned copper wire |
| Current rating: |
1A |
| Insulation: |
Polyethylene, according to KSM & BSM Cable Colour Codes (see the linked resources) |
| Screen: |
Aluminium or aluminium/polyester tape |
| Drain wire: |
1/0.5, (0.22mm²) tinned copper |
| Overall jacket: |
Low smoke zero halogen material, cream |
| Overall diameter: |
6.3mm (KSM-LFH5), 7.6mm (KSM-LFH10), 10.2mm (KSM-LFH20), 10.8mm (KSM-LFH25) |
| CPR Euroclass: |
Eca |
| Conductor resistance: |
98 ohms/km |
| Weight: |
4.7kg/100m (KSM-LFH5), 8.4kg/100m (KSM-LFH10), 15.1kg/100m (KSM-LFH20), 17.0kg/100m (KSM-LFH25) |
| Reel length: |
1000m |
| Cut lengths: |
Available in any multiple of 1 metre |
Manufactured by Draka, part of the Prysmian group of companies.
'LFH' is a registered trademark of Canford Audio Limited.