Is it necessary to install power surge arrester to protect Air defense alarm?
If install an air defense sirens, its principle is ringing after the rotation of an electric motor. when it do not have alarms, and power air switch off, will it be damaged by the lightning current come from the power line? Is it necessary to install the power surge arrester.
In general, lightning electromagnetic pulse (LEMP) are mostly fleeing from the metal wire, power cord is the main conduction line. If you use circuit breaker to cut off all circuit which is possible conduction voltage line, it should say not installed the SPD is not a problem. But the general circuit breaker only disconnect the phase line, there will be voltage-invasive through neutral line.
In general, lightning electromagnetic pulse (LEMP) are mostly fleeing from the metal wire, power cord is the main conduction line. If you use circuit breaker to cut off all circuit which is possible conduction voltage line, it should say not installed the SPD is not a problem. But the general circuit breaker only disconnect the phase line, there will be voltage-invasive through neutral line.
In addition, does the air defense alarm installed on the roof? It should be within the scope of protection of the air terminal, metal shell should be connected with roof lightning protection bar in equipotential bonding.