Functions:
The surge arrester is composed of a semiconductor valve element (varistor) which opens under certain conditions.
Under standard conditions, the surge arrester has infinitely high resistance between the protected conductors and the earth.
At voltage increase due to atmospheric nature or system failure, the varistor opens and conducts the overvoltage towards the earth circuit.
After the standard voltage restores, the varistor closes.
Technical characteristics:
* Rated discharge current (In): the rated value of discharge current can be repeatedly led to the earth.
* Maximum discharge current (Imax): peak value of discharge current which the surge arrester can bear once.
* Rated operating voltage (Uc):
- feedback voltage of the surge arrester: 275/440V; 50Hz
* Surge voltage Up: the voltage created in surge arrester terminals at rated discharge current running.
* Constant operating current: up to 800µA for 1p, 2p, 3p ; up to 600µA for 1p+N, 3p+N
* Indication for damaged surge arrester
Mounting:
- on DIN rail.
- vertical position.
- mounting on the front of the distribution box.
- flexible or rigid conductors with corresponding section.