WTSP-A40 AC Surge Protective Device SPD
WTSP-A40 AC Surge Protective Device SPD, 275V AC, 20kA nominal and 40kA maximum discharge current, Up 2.0kV, 35mm DIN rail.
ac spd
AC surge protective devices that safeguard inverters and AC distribution against transient overvoltages.
ac spd products
Protecting a Board or an Inverter Output?
Send the board layout, the supply arrangement and what is being protected. We reply within 24 hours with the device, the upstream breaker and the wiring diagram.
AC SURGE PROTECTION
AC Surge Protective Devices for Distribution Boards
An AC surge protective device gives a transient a shorter path to earth than through your equipment. It sits in parallel with the supply, normally on the load side of the main breaker, and does nothing until the voltage spikes.
Where it goes depends on what it is protecting. At the service entrance, a Type 1 device handles the surge that comes in on the supply; at a sub-board, a Type 2 device handles the residual surge and switching transients. WTSP-A40 is fitted in the board next to the breakers.
The installation details decide whether it works: short leads to the busbar, a direct earth connection, and an upstream breaker sized for the device. Units carry CE and CCC marking.
Installing an AC SPD
The device type follows the location. The wiring follows the rule that shorter is better.| Location | Device class | What it handles | Note |
|---|---|---|---|
| Service entrance | Type 1 | Partial lightning current | With external lightning protection |
| Sub-board | Type 2 | Switching and induced surges | Most common in distribution |
| At the equipment | Type 3 | Residual surge | Close to sensitive loads |
Wiring rules
- Keep the leads under half a metre. Long leads add inductance, and the voltage drop along them is what reaches your equipment.
- Earth directly to the main earth bar, not through a random screw on the enclosure.
- Fit the upstream breaker the device rating calls for, so a failed device is disconnected rather than burning.
COMMON QUESTIONS
Frequently Asked Questions
Type 1 is installed at the service entrance where a lightning current can enter, Type 2 in sub-boards for switching and induced surges, and Type 3 close to sensitive equipment. A building usually needs a coordinated set, not a single device.
At the point of entry to the installation or the board being protected, on the load side of the main breaker, with short leads to the busbar and a direct earth connection. A device at the far end of a board protects very little.
Yes, a dedicated breaker or fuse selected for the device rating, so a failed device is disconnected safely. Without it, a short-circuited device can burn inside the board.
The status window changes colour when the protection element is spent. Check it at each service and replace the cartridge or the device as indicated.
CONTACT US
Start Your Electrical Project Today
Send your application, voltage, certifications and quantity to this electrical protection manufacturer. We reply with a quotation within 24 hours.
- Engineering review by an electrical protection manufacturer before quoting
- Plant pricing with no intermediaries
- Export packing and shipping handled in one place
- One order owner from quotation to delivery