The basic principle for surge protection is the complexity and coordination of protections. The complexity requirement can be met only by installing surge protections in all inputs and outputs (!) of the given equipment, i.e. it is necessary to protect the feed line, measuring and communication interface. We can ensure
coordination by installing protections with various protective effects in sequence into
the line or the communication core and the interface.
Criteria to meet the requirement for complexity and coordination particularly include installation position or zone boundary, maximum pulse or discharge current, required protection level and response time.
In order to select the correct type of protection for light-current signals, you must also have detailed information on the protected signal:
a) Signal voltage
b) Signal current
c) Frequency bandwidth - frequency and signal form
d) C onduit in lightning protection zones (LPZ 0 to LPZ 2)
e) L ongitudinal impedance - maximum line attenuation
f ) Possibility of steady overvoltage (so-called high-ohm fault)