Technical Guides

SPD Procurement Guide · Samples · Trial Orders · OEM MOQ What is the minimum order quantity (MOQ) for a surge protective device (SPD) manufacturer? Can an OEM buyer order…

Industrial Control Panel Guide VFD surge protection normally starts on the incoming power side of the variable frequency drive, not on its PWM motor output. A correctly selected Type 2…

A surge protective device that has turned black, melted, smoked, cracked or burned has experienced severe electrical or thermal stress. The visible damage confirms that a serious event occurred, but…

The most common causes of SPD failure are repeated surge stress, temporary overvoltage, incorrect Uc or Ucpv selection, wiring errors, unsuitable backup protection, excessive temperature, moisture, and the use of…

Pluggable SPD Replacement Guide In many pluggable SPDs, the removable protection module can be replaced without disconnecting and rewiring the base—but only when the existing base is undamaged and the…

Commercial Distribution Board Wiring Guide This single phase surge protector wiring diagram guide explains how panel builders should connect 1P+N and 2P SPDs, identify L, N and PE terminals, coordinate…

48V / -48V Telecom DC Power Protection Guide Looking for a 48V DC SPD, -48V DC SPD, or telecom DC surge protector for a cabinet, base station, or DC distribution…

SPD Parameter Guide · Up / Residual Voltage When buyers compare surge protective devices, the Up value is often misunderstood. A lower Up usually means better voltage limitation, but it…

TT Earthing System SPD Selection For a TT earthing system, SPD selection should not be based only on pole count. This guide explains when to specify a 3+1 SPD, how…

BESS SPD Selection Guide Not sure where surge protective devices should be installed in a battery energy storage system? This guide explains BESS surge protection for battery cabinets, DC bus,…