Buyer’s guide
Surge Protection (SPD) Selection
Choosing surge protective devices — Type 1, 2 and 3, where to install them and how to coordinate.
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Overview
Surge Protection (SPD) Selection
Surge protective devices (SPDs) protect electrical and electronic equipment from transient overvoltages caused by lightning and switching events. As installations fill with sensitive electronics, SPDs have moved from optional to essential — and selecting the right type for the right location is what makes them effective.
This guide explains the SPD types, where each belongs, and how to coordinate them. Emirates Panel supplies surge protection from Weidmüller and ABB as an authorized distributor.
SPD types
Type 1, Type 2 and Type 3
Type 1 SPDs handle the high-energy partial lightning current and are installed at the service entrance of buildings with an external lightning protection system. Type 2 SPDs handle switching surges and residual lightning energy and are installed in distribution boards. Type 3 SPDs provide fine protection close to sensitive equipment.
They work as a coordinated cascade — each type reduces the surge further as it travels toward the load — so a complete scheme often uses more than one type.
- Type 1: service entrance (lightning current)
- Type 2: distribution boards (switching surges)
- Type 3: at sensitive equipment
- Coordinate as a cascade from source to load
Where to install
Protect at every boundary
Install Type 1 (or combined Type 1+2) at the main incomer, Type 2 in sub-distribution boards, and Type 3 at the final outlet feeding critical electronics such as control systems, IT and instrumentation. The closer the SPD to the equipment, the lower the let-through voltage it must achieve.
Keep connecting leads short and straight — long, looped SPD leads add inductive voltage that undermines the protection, a common installation error.
Coordination & backup
Get the details right
SPDs need a backup overcurrent device (fuse or breaker) sized per the manufacturer’s data, and the SPD’s voltage protection level (Up) must be below the equipment’s withstand. Coordinate types so each operates in its intended role.
Specify SPDs with status indication or remote signalling for critical sites, so a failed SPD is noticed and replaced before the next surge arrives.
Key points
At a glance
Type 1
Service-entrance, high-energy lightning current.
Type 2
Distribution-board switching-surge protection.
Type 3
Fine protection at sensitive equipment.
Short leads
Keep SPD connections short to limit added voltage.
Up level
Voltage protection level must beat equipment withstand.
Standards
Specify to IEC 61643 series.
Avoid these
Common mistakes to avoid
The biggest installation error is long, looped SPD connecting leads, which add inductive voltage and undermine the protection — leads must be short and straight. Skipping the Type 1 device at a building with external lightning protection is another serious omission.
Teams also forget the SPD’s backup overcurrent device, fail to coordinate the types as a cascade, and choose a voltage protection level (Up) that the equipment cannot actually withstand.
How we help
From this guide to delivered product
Reading the theory is one thing; applying it to your project is another. The Emirates Panel technical team turns this guidance into a specific recommendation — the right device, rating and accessories for your duty — and supplies it as genuine, authorized product with the documentation your consultant needs to approve it.
Send your requirement, a one-line or a parts list, and we respond with pricing, availability and lead time, backed by EP Group sourcing across the UAE and GCC.
FAQ
Frequently asked questions
Do I need all three SPD types?
Often yes for full protection — Type 1 at the entrance, Type 2 in boards, Type 3 at sensitive loads — coordinated as a cascade.
Where do Type 1 SPDs go?
At the service entrance of buildings with external lightning protection, to handle partial lightning current.
Why keep SPD leads short?
Long leads add inductive voltage during a surge, raising the let-through voltage and reducing protection — keep them short and straight.
Which SPD brands do you supply?
Weidmüller and ABB surge protection, genuine and warranted, as an authorized distributor.
Need help specifying?
Our technical team helps you select the right product and supplies it genuine, with documentation.
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