An anti-condensation heater may be used in a rotating electrical machine to prevent internal surfaces and atmosphere becoming cold, thereby preventing the formation of moisture in the windings. Because the heater will be energised when the machine is without over-pressure, it is essential that it is explosion protected.
Emergency lighting will normally be installed in pressurised control rooms, cabins etc. and energised when there is loss of over-pressure. These fittings must also be explosion protected, typically Ex e. Solenoids for fire dampers will be Ex d protected. Alarms, over-pressure and flow-rate sensors may use IS protection. Ex d enclosures will be used for control panels.
