Three Phase 4 Pole Surge Protection Device WSPD440
18th Ed. Compliant
2-Year Warranty
UK Stock
Free Delivery £30+
Secure Payments With
Full three-phase surge protection in a compact 4-module device. The WSPD440 is a high-performance 4 Pole Type 2 Surge Protection Device (SPD) for three-phase systems with neutral (3P+N). Rated up to 40kA discharge capacity, it protects against transient overvoltages from lightning strikes, switching surges, and grid disturbances – keeping sensitive...
Full three-phase surge protection in a compact 4-module device.
The WSPD440 is a high-performance 4 Pole Type 2 Surge Protection Device (SPD) for three-phase systems with neutral (3P+N). Rated up to 40kA discharge capacity, it protects against transient overvoltages from lightning strikes, switching surges, and grid disturbances – keeping sensitive equipment and circuits safe.
Designed for residential, commercial, and industrial installs, this DIN-rail mountable SPD ensures compliance with BS7671:2018 Amendment 2 and BS EN 61643-11. A clear mechanical indicator provides instant status checks, while the 4-module width makes integration easy inside distribution boards and panel enclosures.
- Complete coverage: Protects L1, L2, L3, and Neutral
- High capacity: 20kA nominal / 40kA max discharge
- Installer friendly: 35mm DIN rail mount, 2.5–25mm² terminals
- Visual safety: Red/green fault status indicators
- Standards compliant: BS7671 & BS EN 61643-11
- Applications: EV charging, industrial machinery, commercial boards
When to Use This SPD
| SPD Type | Protection Provided | Best For |
|---|---|---|
| 4 Pole (3P+N) | Protects all three phases + neutral | Three-phase boards, EV hubs, industrial equipment |
| Single Phase | Protects line + neutral | Domestic consumer units & small commercial installs |
| 3 Pole (No Neutral) | Protects L1, L2, L3 | Balanced three-phase systems without neutral |
What does a 4 pole SPD protect?
It protects all three phases and the neutral (3P+N), giving full coverage for balanced and unbalanced loads in three-phase systems.
Does this SPD comply with 18th Edition regulations?
Yes – it meets BS EN 61643-11 and fully complies with 18th Edition surge protection requirements for residential, commercial, and industrial sites.
Where should I install this SPD?
As close as possible to the origin of supply – usually in the main distribution board – with a short, direct earth connection to minimise let-through voltage.
| Product Code | WSPD440 |
| SPD Type | Type 2 (3P+N) |
| Poles | 4 (L1, L2, L3, N) |
| Nominal Discharge Current (In) | 20kA |
| Max Discharge Current (Imax) | 40kA |
| Operating Voltage | 230/400V AC (Uc 275V) |
| Mounting | 35mm DIN rail |
| Terminal Capacity | 2.5–25mm² |
| Status Indicators | Mechanical (red/green) |
| IP Rating | IP20 |
| Temperature Range | -40°C to +85°C |
| Standards | BS EN 61643-11 / BS7671:2018+A2:2022 |
Install upstream of final circuits, as close to the incoming supply as possible. Suitable for TN-S and TT systems with a neutral connection. Always ensure correct earthing and bonding.
- Mount on DIN rail inside an enclosure or consumer unit
- Connect L1, L2, L3, and Neutral to labelled terminals
- Use the shortest possible earth conductor to the MET
- Check green/red indicator for live operational status
