DC string circuit-breakers PKZ-SOL
String circuit-breakers instead of fuses
String circuit-breakers PKZ-SOL are the fuseless alternative for the protection of photovoltaic modules against short circuit.
With their variable trip range, they can be optimally adjusted to the actual short-circuit current of a string. A thermal release reacts at 1.05 … 1.3 fold current and the magnetic release at 6-fold current.
Using the optional undervoltage release U-PKZ0, remote switching, for example, for the fire brigade is possible.
The easily fitted auxiliary switch NHI-E-PKZ0 provides switch state information.
Only the current ratings of the installed overload release are present on the current setting of the circuit-breaker compliant to IEC/EN 60947-2 (section 4.7.3).
For this reason, the tripping current of the switching device and the short-circuit current of the photovoltaic modules must be specified in a suitable format for every point on the scale.
| Circuit-breaker tripping current | Permissible solar module currents | |||
Nominal value A |
|
Short-circuit current A |
Rated current at 110 % short-circuit current A | |
4 |
2,5 4 |
1,6 3 |
1,5 2,5 |
|
7 |
4 7 |
2,6 5 |
2,5 5 |
|
12 |
8 – 12 |
5 – 9 |
5 8 |
|
20 |
14 – 20 |
9 – 15 |
8 14 |
|
30 |
23 – 30 |
15 – 22 |
14 20 |
|