Fire alarm cable is an essential part of the installation of any fire detection system.
All Certified Installers will insist on compliant Fire Alarm cables and will select the cable that is best fit for purpose. This depends on the design of the system, but essentially most cables are similar in design and are usually either a flat cable, a circular twisted pair or in some cases Fire Rated or have Low Smoke Zero Halogen materials.
In 2010 changes to NZS4512 specified that “cable used within a building for detector circuits, alerting devices, loudspeaker circuits or ancillary control circuits shall generally comply with AS/NZS5000.2 or AS/NZS5000.3 and shall either be sheathed in polyvinyl chloride or installed in conduit.” Refer Section 402.1. Both AS/NZS5000.2 and AS/NZS5000.3 are the Standards for 450/750 volt cables. We understand the objective is to have cables with a higher level of mechanical protection.
One of the biggest impacts of these changes is for a circular multicore cable the outer sheath had to be a minimum thickness of 1.2mm, refer sections 8.3.2 and 13.2 in the respective Standards. Previously flat cables were 0.90mm so the additional thickness, 33% more PVC, coupled with the cables being circular in design, proved to make them more difficult to strip, especially where longer tails may be required, e.g. control panels.
Being the leading manufacturer of cables for the Fire Detection market Tycab came up with the innovative “Tyrip” concept. In simple terms it is the inclusion of a seam/strip so that the installer can rip the sheath open using one or all of the conductors in the cable.
These cables are manufactured to meet AS/NZS3808 “Insulation and Sheathing Materials for Electric Cables”. This Standard specifies the required tensile strength for various types of materials. Tycab’s innovative extrusion tool ensures the softer strip does not compromise the compliance with the AS/NZS3808 or other relevant Standard.
The key benefit for the installer is it makes the stripping of the outer sheath and exposing the conductors for termination much easier and hopefully the whole process more productive. There is also less likelihood of inadvertently damaging the insulation on the conductors.
Tycab has always been at the leading edge when it comes to innovations that make it easier for the installer. Previous examples included the introduction of:
- The efficient and easy to use reel in a box, no more cable rollers.
- The 0.75mm twisted pair cable following changes to NZS4512, excellent for cost savings where there are smaller runs and no risk of voltage drop.
- Tinned conductors to provide that extra level of robustness in some of New Zealand’s harsher environments.