The electrical installation within the cubicles is in accordance with BS 7671.
The electrical equipment is suitable for operation in an outdoor environment and to be housed in a cubicle rated at IP66. All components conform to a MTBF of 15,000 hours. Reliability is designed to be 100% with a life of 25 years.
All live terminals and components are shrouded to prevent inadvertent contact.
The quality and rating of the circuit protection devices (fuses and MCBs) required in each cubicle are designed to be appropriate to the individual circuit requirements and are of a suitable rating to allow for the specific inrush characteristics of the self-regulating heater element.
For effective circuit discrimination each transformer primary circuit is protected by BS 88 cartridge fuses and each 110 volt secondary heater feeder circuit is protected by a double pole MCB.
All protective devices and components are mounted within clear fronted sub assembly enclosures mounted onto the backplate of the enclosure.
An anti-condensation heater is mounted inside the cubicle in an appropriate position and is controlled from a pre-set thermostat, which is also mounted in the cubicle.
A bulkhead type of lamp fitting is mounted inside the enclosure, which is controlled from the door-operated switch.
To isolate the mains supply into the cubicle a main isolating switch is fitted which can only be operated after opening the cubicle door.
A manual override facility is also included in the control cubicle to ‘override’ the weather monitoring devices and energise the heating circuit under all ambient conditions. This override facility is fitted for maintenance and test purposes only and in the event that the control cubicle is left in ‘override’ mode the circuit will revert to its normal ‘auto’ mode after 60 minutes.