Increased Safety Lighting

The Burn Brite Lights increased safety (Ex e) lighting system uses a combination of flameproof and increased safety equipment to reduce maintenance and spare parts costs.

The increased safety lighting system consists of four major components:

• Primary supply cable
• Ex e isolator box (with or without switch)
• Secondary lighting cable
• Light assembly

The supply or primary cable is a hazardous location trailing cable with pilot protection circuits. It may be either single or three phase. This cable is run along the face from the lighting supply transformer to the first isolator box and then looped to subsequent boxes mounted on the shields. To minimise voltage drop along long faces, this cable is often 10mm² or 16mm² (more common).

The isolator is an IP66 enclosure and houses the primary sockets, secondary sockets, terminals and switches. The Burn Brite enclosure also houses fuses and power factor correction capacitor (if required). The fuses are necessary to provide isolation of faulty secondary cables and/or luminaires. They also serve to provide protection due to break of gauge from a 16mm² primary to 1.5mm² secondary cables. The enclosures are of folded and welded stainless steel construction.

In practice they provide convenient connections of a smaller secondary cable to the heavier (16mm²) primary supply cable.

The secondary cables used with flameproof lighting are similar to the primary cable, although they may or may not include pilot conductors. They must not be disconnected or replaced while energised, as a spark may be produced upon opening the circuit.