Fireproof Cable Joints For BS7846 Fireproof Mains & Control Cables (LSZH)
Published 07 Feb 2019
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uploaded by Chris Dodds - Thorne & Derrick Sales & Marketing Manager
BS7846 Cables
Thorne & Derrick International distribute fireproof cable joints for LV Low Voltage fire resistant armoured (SWA) power cables to British Standards BS6387 and BS7846.
The BS7846 British Standard enhanced fire performance cable is specified for fire alarms and emergency lighting in both indoor and outdoor installations – general fire resistant power cables are used to protect emergency plant including sprinkler pumps, smoke extractors and fire dampers.
The British Standards
BS6387:2013 : Test Method For Resistance To Fire Of Cables Required To Maintain Circuit Integrity Under Fire Conditions.
BS 7846:2015 : Electric Cables. Thermosetting Insulated, Armoured, Fire-Resistant Cables Of Rated Voltage 600/1000 V For Fixed Installations (having low emission of smoke and corrosive gases when affected by fire).
BS7846 Cable Construction
| Conductor | Annealed plain or tinned copper (Class 2) |
| Insulation | GP6 or GP8 with levels of HCI no greater than 0.5% |
| Bedding | Polymeric materials with levels of HCI no greater than 0.5% |
| Armour | Galvanised steel wires or galvanised interlocking steel tape |
| Outersheath | Polymeric material conforming to the requirements for LTS 1 contained in BS7655-6.1 |
BS7846 Cable Core Identification
| Number of Cores | Identification |
| Two-core | Brown and blue |
| Three-core | Brown, black and grey |
| Four-core | Blue, brown, black and grey |
| Five-core | Green and yellow, blue, brown, black and grey |
BS7846 Cable Fire Resistance CategoriesÂ
The cables under the British Standard are categorised according to their special fire resistance characteristics:
| F2 | Resistance to fire, resistance wear, resistance to fire with mechanical shock, assessed separately when tested in accordance with this Standard |
| F30 | Resistance to fire with direct mechanical impact and fire assessed in combination for 30mins when tested in accordance with British Standard BS8491 for 30mins |
| F60 | As per F30 for 60mins |
| F120 | As per F30 for 120mins |
Fire Resistant Armoured Power Cable For Essential Services
BS7846 fire resistant cable manufactured by Prysmian features a plain annealed stranded copper conductor, XLPE insulation, MICA fire resistant tape, polyester tape low smoke zero halogen bedding, fire barrier tape and black low smoke zero halogen outer sheath with a galvanised steel wired armour (SWA).
Low smoke zero halogen (LSZH) heat shrink cable joints with additional fireproof or fire resistant properties are available – typically used to connect, repair or joint Prysmian FP600S or Prysmian FP400 cables. The cable joints feature low smoke and corrosive gas emissions (LSOH) and are moisture resistant with LUL Approvals.
See also : Low Smoke Zero Halogen (LSOH) Cable Accessories
- BS6387/BS7846 Cable Enhanced Fireproof Mains CableÂ
2, 3 & 4 Core 4sqmm – 400sqmm. Plain annealed stranded copper conductor, mica fire resistant tape, XLPE insulated, polyester tape, low smoke zero halogen (LSZH) bedding, fire barrier tape, galvanised steel wire armour, low smoke zero halogen (LSZH) outer sheath. Sheath Colour Black. 600/1000 grade volts.
Manufactured to meet the following standards – circuit integrity: BS8519-2010 120 minutes/BS8491, acid gas emission to IEC 60754, BS EN 50267, flame propagation to IEC 60332-3, BS EN 50265, BS EN50266 and smoke emission to IEC 61034, BS EN 50268.
Cable Joints
SPS fireproof cable joints utilise LSF zero halogen heat shrink tubes and fire barrier tubes – the joints incorporate mica tape over each of the conductor cores. Micaca tape is a slit silica tape constructed from 96% pure silica fibre, coated one side with a pressure adhesive backing that facilitates installation of the joint kit.
âž¡ Watch the Installation Video for Fire Resistant & Zero Halogen Cable Joints HERE.
Fire resistant cable joints ensure vital emergency circuit integrity in fire conditions – cable joint kit contents include fire protection sleeve, stainless steel clamping spring, inner and outer sealing sleeve, tinner copper earth braid, tinned copper earth mesh, insulation tubes, mica pads and crimp ferrules.
LONDON UNDERGROUND APPROVED
Developed specifically for London Underground Limited (LUL) and for use within underground rail tunnels and above surface at platform and station level, the low smoke zero halogen cable joint incorporates flame retardant, non halogen polyolefin heat shrink tubing with a meltable inner liner providing excellent flame retardant properties with reduced acid gas emission and smoke generation.
A complete range of multicore and multipair cable joints are available with LUÂ approval for rail power, signals and telecoms cables.
Fire Resistant Cable Accessories
Thorne & Derrick International distribute the complete range of Fire Resistant Cable Accessories to preserve and power low voltage electrical systems without compromising the manufacturing standards according to BS7846 – complete ranges of cable clips, cleats (including claw cleats) and glands are also available to support the installation of Prysmian FP specification cables.
| Clips | Firefix | Claw Cleat (Single hole – stackable) | 2 Bolt Cleat (Stackable) | Traditional FP Gland | FP Easy Fit Gland | Brass Gland | |
| FP600S | – | – | BICON 370CG | BICON 370CG | – | – | BICON LSF-CW |
| FP200 GOLD | AP Clips | FP Firefix Single or Double | – | – | 251, 252, 254 | FP2520 | BICON A1/A2 423 L |
| FP PLUS | AP Clips | FP Firefix Single or Double | – | – | 251, 252, 254 | FP2520 | BICON A1/A2 423 L |
| FP400 | – | – | BICON 370CG | BICON 370CG | – | – | BICON LSF-CW |
Cable Breakouts | Cable Caps | Cable Lugs | Cable Cleats | Cable Trough | Cable Duct | Feeder Pillars | for 11kV/33kV/66kV networks see MV HV Joints & Terminations
Further Reading
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Prysmian FP400 Fire Resistant Power Cable – BS6387 CWZ Armoured Cables
Size: 130.56 KB
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Prysmian FP600S Fire Resistant Power Cable – BS8491 F120 Armoured Cables
Size: 156.65 KB
