Protecting Transpower Haywood

19 June 2015

Transpower New Zealand Limited is the state-owned enterprise responsible for electric power transmission in New Zealand. It performs two major functions in the New Zealand electricity market, providing the infrastructure of electric power transmission that allows consumers to have access to generation from a wide range of sources and as system operator it manages the real-time operation of the grid and the physical operation of the electricity market.

Transpower New Zealand were looking to protect their Auxiliary Power Rooms, Control Rooms and Condensers as well as the Cable Basement at the Haywood Sub Station in New Zealand. Fire Protection Technologies supplied Aquaheat Limited with special hazard fire protection systems for installation at the Haywood Sub Station, working together on the design and engineering aspects of the system.

Fire Protection Technologies supplied 29 80 litre 300 bar ProInert IG55 cylinders in a standard flooding system to protect the auxiliary power rooms, control rooms and condensers as well as extended discharge cylinders complete with 2 selector valves.

Two condensers are installed currently with an old CO2 system, Transpower were looking to replace this system with a similar system using an Inert agent such as ProInert IG55 to eliminate the inherent dangers of flooding an area with CO2. We have designed a suitable Selector Valve System protecting two condensers with selector valves. The system will discharge an initial quantity of agent and then bleed more agent into the enclosure over a 60 minute period, this is to make up for any losses of agent while the Condenser is running down to a full stop.

To protect the Cable Basement space Fire Protection Technologies supplied a complete Vortex Hybrid Watermist system including a total of 54, 80 litre, 200 bar cylinders complete with 2, 120 gallon water tanks and another 54 reserve Vortex Nitrogen Cylinders. The consultant chose Vortex over standard gaseous fire suppression systems due to the multiple cable penetrations and the potential leakage of the risk, standard gaseous systems may not have achieved the retention times necessary without significant sealing of the cable penetrations.