What Are Surge Protective Devices (SPDs), and Which Type Does Your Facility Need?
Quick Answer: A surge protective device (SPD) limits transient overvoltages — from lightning, utility switching, and internal load switching — to protect equipment. Type 1 SPDs connect on the line side of the service disconnect (utility side); Type 2 SPDs connect on the load side, including at branch panels. Most facilities use a layered approach: […]