What can happen if the MCOV of an SPD is not appropriately selected?

Selecting the appropriate Maximum Continuous Operating Voltage (MCOV) for a Surge Protective Device (SPD) is critical to its performance and reliability. If the MCOV is not appropriately selected, the SPD may conduct constantly, which is a direct result of the device being exposed to voltages beyond its rated capacity. This constant conduction can lead to overheating, premature failure, or complete burnout of the SPD.

When the voltage levels exceed the MCOV, the SPD may continuously divert the excess voltage away from sensitive equipment, failing to provide the necessary surge protection effectively. This situation negates the primary function of the SPD, which is to protect against voltage spikes, as it becomes a pathway for regular operational voltage, thus rendering it ineffective for surge protection and risking damage to the connected systems.

This scenario highlights the importance of correctly assessing and matching the MCOV to the system voltage to ensure that the SPD can handle the normal operating conditions without compromising its protective capabilities.