Fire Resistant Cable Ties Support BS7671 Compliant Fire Alarm & Detection Installations

By Chris Dodds on 19th May, 2015

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Fire Resistant Cable Ties Support BS7671 Compliant Fire Alarm & Detection Installations

Fixing Cables In Escape Routes Using Fire Resistant Cable Ties.

In this second in a new series of Guest Blogs by NICEIC registered electrical contractors, we discuss and clarify the recent changes to BS7671 17th Edition Electrical Regulations and the subsequent impact upon the specification of fire resistant cable supports and fire alarm and detection systems. 

Commonly referred to as "The Third Amendment".

We benefit from the views and expert technical input from Mayhew Electrical, a fully approved NICEIC Mayhew Electrical Contractorselectrical contractor, providing a complete industrial, commercial and domestic electrical installation service.

Mayhew Electrical specialise in Inspection & Testing services to BS7671, including electrical installation condition reporting and today explain how they have proactively responded to BS7671.

Who Are NICEIC?

NICEIC aims to protect everyone who uses electricity from unsafe electrical installations anywhere.

To achieve this, NICEIC maintain a register of qualified, competent electricians.

NICEIC Approved Contractor

Too Hot To Handle?

As of 1st January 2015 new regulations, under BS7671 Amendment 3, were introduced to combat the dangers to life and property posed by the use of plastic fastenings and fixings including cable ties, clips and bases.

Focus was placed upon the essential requirement to support cables with fire resistant fastenings and fixings which resist premature collapse in fire conditions. Consequently, plastic cable clips, plastic cable trunking and non-metallic cable ties cannot be used as the sole support method for wiring systems, especially safety critical escape routes. 

BS7671 regulations were updated to ensure cable accessories installed onto fire resistant cables and systems are capable of preserving the integrity of the fire rated electrical circuits - substandard or under-specified plastic cable supports and ties are potentially incendiary ingredients fuelling the fire and adding to the debris rather than supporting the safe evacuation of people via escape routes.

Cables supporting fire escape routes in corridors and staircases must be installed using fire resistant fixings and fasteners to comply with BS7671 - materials must resist the effects of fire and subsequent cable collapse posing a serious risk to life. 

Clearly, cable fixings, fasteners or supports (whether cable tray, trunking or cable ties) should not compromise the circuit integrity below that of the fire resistant cable specification.  

Put simply, fire resistant cables should be supported by fire resistant cable supports. 

Pictured : Excerpted from BS7671, IET Wiring Reg's - 3rd Amendment

Fire Resistant Cable Ties BS7671

BS7671

 

Amendment 3 to BS 7671: 2008 : Proposed Regulation 521.11.201


521.11.201 Wiring systems in escape routes shall be supported such that they will not be liable to premature collapse in the event of fire.

The requirements of Regulation 422.2.1 shall also apply, irrespective of the classification of the conditions for evacuation in an emergency.

1: Non-metallic cable trunking or other non-metallic means of support can fail when subject to either direct flame or hot products of combustion. This may lead to wiring systems hanging across access or egress routes such that they hinder evacuation and firefighting activities.


2: This precludes the use of non-metallic cable clips, cable ties or cable trunking as the sole means of support. For example, where non-metallic cable trunking is used, a suitable fire-resistant means of support/retention must be provided to prevent cables falling out in the event of fire.

 

Pictured : In February 2013 the Coroners Court concluded dropped service cables trapped firefighters contributing to their deaths at a fire in Southampton during 2010. Several separate firefighter fatalities have been directly attributed to the use of combustible cable support systems, including plastic trunking and the consequent entanglement in electrical cabling.

 Image : Hampshire Fire & Rescue Service.   

Fire Resistant Cable Ties   

A View From The Frontline

As mentioned, Mayhew Electrical are specialist Fire Alarm and Detection System installers based in Chelmsford, Essex, UK. Here we now draw upon their practical project experience and learn how they have conciously reacted to BS7671 and responsibly focussed attention on the material specification of cable containment and support used on site. 

"While we carried out the recent installation of a replacement fire alarm panel we took the step of updating the installation in line with latest version of BS5839 and also incorporated measures to comply with requirements of Amendment 3 of BS7671 - we paid strong attention during a fire risk assessment to the existing wiring system and the installed materials on site. We assessed the likelihood of insitu trunking, cable ties and fixings to actually withstand fire intensity and guided by BS7671 and best practice carried out some essential upgrade to fire safety for the client, their people and their assets" comments Keith Mayhew (MD).

"As a start by utilising Panduit stainless steel cable ties as a supplement to the original plastic ties (typically 1 stainless steel tie per metre), we have made provision to prevent any risk of fixing failure allowing cables to fall potentially injuring or trapping people or fire fighters. This is a good way of quickly updating existing installations to comply."

"Mayhew Electrical are involved in a lot of cable basket and cable tray installations so the purchase of a cable tie gun was cost effective. Stainless steel cable ties can be set equally well with normal pliers and side cutters, however steps should be taken to ensure the cut “tail” is as short as possible and folded or positioned to prevent any risk of injuring future installers or end users."

"Where we are involved in new installation design, we are specifying cable management systems that are installed to cradle cables and fixed using all metal fasteners, supplementary stainless ties may still be required on vertical runs or around final termination points." 

The following Flickr Album from Mayhew Electrical highlights key areas and applications for Panduit stainless steel cable ties on the recent fire alarm and detection system.

Content from Mayhew Electrical : Project Gallery (April 2015) Fire & Smoke Alarm Cabling and System - BS7671 Electrical Installations (IEE Wiring Regulations, 17th Edition)

Comply or Die?

Sounds stark but it is true. Unless BS7671 compliance is observed then future fatalities will occur sooner or later.

As we have highlighted, under the new BS7671 regulations, stainless steel cable ties have increasingly been adopted for bundling and locating fire alarm and detection cables.

Stainless steel cable ties provide a high strength, reliable and fire resistant cable fixing. 

A common choice for contractors is the Panduit range of stainless steel ball lock cable ties suitable for cable bundle diameters up to 355mm and a minimum loop tensile strength of 450lbs. Panduit MLT stainless steel cable ties (grade 304) withstand temperature excursions to 538 Degrees celsius - they are fire proof.   

A final word of warning, the UK market has seen a flood of unbranded imported stainless steel cable ties over the years.

T&D have sample tested certain batches and observed problems ranging from metal ball-bearing mechanism failure and cutting risks posed to installers hands due to razor sharp edges.

The cost may seem very low but the price could be very high.

BS7671 is there to save lives and control the specification and high quality of installed cable components. Now that has been achieved, it would be a sad outcome if our safety remained in jeopardy due to contractors cutting the cost-corner. 

Tip, stick to a brand you can trust.

 

Reputation Matters - Place Trust In Panduit Panduit

Panduit are the world leader in innovating and manufacturing stainless steel cable tie and banding systems for cable support in harsh and hazardous area installations.

The following comments from Andrej Nikolic and Sarah Short (Former Social Media Manager) at Panduit outline the selection criterion for stainless steel cable ties.  

Keeping your communications and power cables properly and safely installed in harsh environments can be a challenge. The importance of proper installation is imperative for facility and personnel safety.

In order to ensure that proper cable fastening solutions are being implemented, stainless steel cable ties may be specified. 

Many people choose stainless steel ties because they are thoroughly non-flammable. They will not catch on fire nor will they cause a fire to occur. They can be installed in extremely high temperature environments as the melting point of the alloy is in excess of 1400 Degrees celsius.

BUT...not all stainless steel cable ties are created equal. We recommend 5 steps to evaluating and selecting your stainless steel cable ties : 

1.            Evaluate your environment.  Do you have a corrosive environment with exposure to chemicals, radiation or severe weather or temperature?  Is your application underground?  Will it be exposed to direct sunlight?

2.            What grade of stainless do I need? At the bare minimum, go with AISI 304 grade stainless for the harsh environment applications listed above.  Many times, AISI 316 is more prudent in severe corrosive environments. 

3.            SAFETY! Since installers will be handling these cable ties day in and day out, it is critical to use ties with smooth edges to avoid scrapes and cuts.

4.            Evaluate your application. If vibration is a regular occurrence you will want to select a tested and validated cable tie that won't loosen over time.

5.            What tensile strength do I need?  Tensile strength, also known as the breaking strength of the tie, is measured in Newton or Pounds. The higher the tensile strength, the stronger the tie.

Choosing a good stainless steel cable tie is an important first step, but in order to ensure a fully successful installation, one must also use reliable installation tools as well.  The key function of an installation tool is to safely and properly tension the tie around the bundle, and cut off the excess tie material without leaving any dangerous sharp edges that can cause injury to the facility staff. 

When choosing your stainless cable tie supplier, make sure to also look for global and reputable third party agency approvals or certifications such as UL, ABS, DNV, BV and CE, among others. 

Panduit offers a comprehensive, premium and cost-effective line of stainless steel ties and strapping products to meet any need within these harsh environment applications. 

For more information please visit www.panduit.com.  

 

 

Pictured : Panduit MLT Ball-Lock Stainless Steel Cable Ties - Fire Resistant

Panduit Cable Ties

 

 

By Martin Bainbridge EngTech GIFireE, MIFPO, MIFSM, SIIRSM RSP
 
Panduit Cable Ties

 
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Panduit Pan-Steel Cable Ties For Fire Resistant Cable Support





Category:  Cable Cleats & Cable Ties

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