Project: Installation of fire-retardant and temperature-resistant power and lighting conduit at New Zealand’s cool store project

Evcco’s HFT conduit is a halogen-free, fire-retardant and temperature-resistant plastic conduit that would be as robust as galvanised steel but as easy to work with as PVC.

The Evcco HFT range of conduit and fittings offers compliance with AS/NZS 2053 as a ‘non-flame propagating’ conduit as it is manufactured using advanced fire-resistant polymer materials. The conduit is rated for operation from -40 up to 110°C, offering an extended temperature range that helps keep critical systems running longer in an emergency. It is highly resistant to a wide range of acids, alkalis, cleaners, detergents and sanitisers. Evcco HFT conduit is coloured grey, stocked in sizes ranging from 20-150 mm and is supported by a comprehensive range of junction boxes, elbows, tees, bends and adapters.

One of the first users of the conduit was Fonterra - a New Zealand-based dairy company. With operating temperatures ranging from 10°C down to minus 18°C, a metal conduit system was the expected choice for Fonterra’s cool store project; but that choice came with the usual drawbacks - compared to plastic conduit, galvanised steel conduit is dirty, cumbersome and more difficult to install.

Contractor Dickson Gray Electrical was on the job, and Director Grant Megson says at the time they had heard about a new type of plastic conduit. Wholesaler JA Russell received an advance sample of Evcco halogen-free, fire-retardant and temperature-resistant plastic conduit from Marley NZ. JA Russell submitted the sample to Dickson Gray Electrical and, convinced by the sample and the specifications, Dickson was able to submit an alternative design specification for the conduit system with the aim of making the job easier without compromising the performance of the finished installation. This substitution was readily accepted because the temperature rating of the Evcco HFT product covered the range required, says Megson.

For Dickson Gray Electrical it was a 14-month-long project with up to 45 staff during peak activity. “The Evcco conduit saved significant installation time throughout the project because it was so easy to install,” says Megson. He says the installation was a lot quicker than galvanised steel conduit because Evcco HFT is just as easy to work with as PVC conduit. The lightweight conduit can be cut using normal PVC conduit cutters, and steel pipe threading machines are simply not required.

Evcco HFT also offers rubber-sealed joiners so they just clip together, says Megson. “This allows for movement as the temperature drops from the ambient day temperature at installation down to the much colder operating temperatures.”

Marley New Zealand’s National Electrical Sales Manager, James Buchanan, says this is a key element of the versatility of the new conduit. Evcco HFT conduit can be installed by using either a special permanent 3M adhesive or purpose-designed, rubber-sealed joiners, bends and plain-to-screw adapters. The HFT rubber joint fittings offer IP67-compliant protection from water and dust. The conduit can also be bent manually.

The halogen-free, flame-retardant specifications support the use of HFT conduit in fire safety-related applications, like tunnels, fire egress and ventilation systems, says Buchanan. “In the event of a major fire, Evcco HFT emits a low smoke density and will not produce toxic fumes. This reduces the risk of respiratory damage for building occupants and gives better visibility both for those evacuating and incoming rescue teams,” Buchanan adds.

Acidic fumes caused by burning products containing halogens can be a major cause of fire damage to electronic and computer circuitry and control systems - even in small fires. “But during a fire the Evcco HFT conduit does not emit corrosive or acidic gas that causes secondary damage to electronic equipment. This makes it ideal for critical communications and network cabling.” Where sustainability is an important design requirement, Evcco HFT can contribute to the Green Star rating system run by the NZ Building Council.

The materials used in the conduit also have benefits in other industries where extensive use of chemical cleaning agents in washdown areas has usually required the use of metal conduits.