Surge protector (SPD)
PV DC SPD, Type 2, 600 V · DIN-rail module, two pluggable varistor cartridges with a status window each · Uc 600 V DC, In 20 kA, Imax 40 kA (8/20 µs), Up 2.5 kV · one cartridge from each line to PE, so line-to-line clamps through the two in series · PE to the grounding electrode with the shortest lead you can · when a cartridge has taken more than it can, its thermal disconnector opens it and the window turns red: replace it
Try it on the benchThe lab drops it on an empty bench and opens its datasheet card.
Typical part: Type 2 SPD, DIN-rail (PV DC 600 / 1000 V, AC 275 V)
Pins
- PV+
- PV−
- PE
Ratings and limits
| Uc (max continuous) | 600 or 1000 V DC · 275 V AC |
|---|---|
| In / Imax (8/20 µs) | 20 kA / 40 kA |
| Up (protection level) | ≈ 2.5 kV (600 V DC) · 1.5 kV (AC) |
| Cartridges | two, pluggable, status window each |
| Leads to PE | as short as possible, ≤ 0.5 m total |
How to use it
One module at the controller’s or inverter’s PV input (DC) and one at the AC panel. Each varistor sits between a line and PE, so a surge on either line is shunted to earth and a line-to-line surge is clamped by the two in series. Its PE lead length matters more than its kA rating: 1 m of wire adds about 1 kV to the clamping voltage during a 20 kA strike. A red window means the cartridge has done its job and must be replaced.
Lessons and builds that use it
- Grounding, bonding and surge protection: the two jobs of earth
- Commissioning and troubleshooting: the checklist and the fault
- Exam: this system fails on cold mornings