What surge protection device coordination is required for a residential main distribution board?

Residential main distribution boards require a three-stage surge protection coordination scheme per IEC 61643-11 and IEC 62305-4. A Type 1 SPD (Class I) with a 10/350 μs waveform impulse current rating of at least 12.5 kA per pole must be installed at the service entrance to handle direct lightning current. Downstream, a Type 2 SPD (Class II) rated for an 8/20 μs waveform with a nominal discharge current (In) of 5 kA minimum provides overvoltage protection at sub-distribution levels. For sensitive terminal equipment, a Type 3 SPD (Class III) with a combination wave Uoc of 6 kV ensures fine protection. Coordination requires at least 10 meters of cable length or dedicated decoupling inductors between stages to ensure proper energy distribution, as verified by Chinnee Electric’s application guidelines for residential installations.