<Safety Instruction> Chapter 5A | Suppressing threats to circuits that enter the premises
Here our objective is to avoid or mitigate damage to critical infrastructure where the point of origin is outside the building which houses the enterprise. There are three main areas where action is typically recommended:
01 Protection of Utility Power at the Electric Panel or Meter
The value of using uninterruptible power supplies to protect certain high value equipment was discussed in the preceding section. And, indeed, a UPS does that well.
However, the first step, and one that is often omitted when engineering the power distribution system is to add a power protection device at the electrical service panel. Alternatively, in some jurisdictions, such a device can be located outside the premises in the electric meter base.
Regardless, the purpose of such a device is to shunt high voltage which may appear on the power line to ground. The addition of this equipment greatly increases the probability that the various components within the building that are connected to AC power will survive events such as lightning which results in direct contact with the outside conductors, induced current caused by electromagnetic pulse or a phase-to-phase short.