SWITCHGEAR ASSEMBLIES FOR NUCLEAR GENERATING PLANTS SERVICE CONDITIONS
The service conditions below are significant to the qualification of switchgear assemblies and included components. Usual Service Conditions The values given as usual service conditions represent the anticipated average conditions for switchgear assemblies in nuclear power generating stations. These values are recommended for use in generic qualification programs and do not imply a derating of the equipment. Ambient Temperature A yearly average ambient temperature of 30 °C with temperature excursions to 10 °C and 40 °C is considered usual. Relative Humidity Relative humidity variations between 10% and 90% are considered usual. Altitude Altitudes of up to 6600 ft (2000 m) above sea level for metal-enclosed low-voltage power circuit breaker switchgear and up to 3300 ft (1000 m) for metal-clad switchgear and metal-enclosed interrupter switchgear are considered usual. Radiation Radiation exposure of up to 104 rads equivalent gamma tota...
