Surge protection in UAE panels is no longer optional — DEWA, ADDC, and most main-contractor specifications now require IEC 61643-rated SPDs at every distribution level. Heres how to lay them out and what part numbers to use.
The three SPD types
- Type 1: Lightning current arrester. Installed at the building main incomer (typically near the LV transformer / main MCCB). Rated by impulse current Iimp (kA, 10/350 µs waveform). Common values: 12.5 kA, 25 kA per pole. Required where direct-strike risk exists.
- Type 2: Surge arrester. Installed at sub-distribution boards. Rated by nominal discharge current In and max discharge current Imax (8/20 µs). Common values: In=20 kA, Imax=40-80 kA.
- Type 3: Point-of-use protection. Installed at sensitive equipment (PLCs, CCTV, instrumentation). Rated by combined impulse Uoc (typically 6 kV).
Where each goes in the panel hierarchy
| Panel level | SPD type | Typical Brand Codes |
|---|---|---|
| Main LV switchboard | Type 1+2 (combined) | ABB OVR T1+T2 series, Schneider iPRD1, Phoenix Contact FLASHTRAB |
| Sub-distribution / floor panel | Type 2 | ABB OVR T2, Schneider iPRD, Phoenix Contact VAL-MS |
| Final circuit / control panel | Type 3 or Type 2+3 | Schneider iPRC, Phoenix Contact PLUGTRAB |
Common mistakes
- Installing only Type 2 at the incomer where a Type 1 is required — Type 2 alone will be destroyed by a real lightning strike.
- Forgetting the upstream MCB/fuse — every SPD needs a backup overcurrent device, typically gG fuse 63A or 125A depending on rating.
- Wire length too long — the SPD lead length from busbar to earth should be < 50 cm. Each extra metre adds significant residual voltage.
- Missing remote indication — most SPDs have an NC contact that should be wired back to the BMS so blown cartridges get replaced before the next strike.
Sourcing
EPFINDER stocks ABB OVR (T1, T2, T3 ranges), Schneider iPRD / iPRC, and Phoenix Contact FLASHTRAB / VAL-MS / PLUGTRAB in our Dubai warehouse. We can supply complete SPD coordination studies on request as part of a project quote. Request a quote.
