electrician, heavy-up,electrical repair
Written by Larry Cook

Surge Protection for Commercial Facilities – Part 3

As discussed in Part 2, almost every enterprise must rely on modern electrical equipment in some way, and they can be degraded or damaged by power surges. Business continuity can be endangered without proper protection. Part 3 will cover Surge Suppression Devices, Selection, and Uninterruptible Power Supply. 

Surge Suppression Devices

Regulating voltage supplied to electric devices, surge suppression devices divert or block voltages when they reach unsafe levels. Their installations are done with a staged, cascaded or layered configuration for the diversion of surges at various points inside an electrical system.

Surge suppressors installed at points where power enters the facility provide the first defensive shield from surges that are externally generated. They safeguard against lightning, grid switching, power system issues, bad weather, and surrounding facilities.

The second defensive shield is provided by surge suppressors installed at the distribution panel, which handles power distribution for a facility. They provide protection from medium to high external or internal power surges.

The installation of surge suppression devices at branch panels will safeguard against low level surges produced by load equipment, such as office equipment, lighting controls, and industrial systems. Sensitive equipment and particular circuits may be especially vulnerable and require individual protection from low level surges.


Select devices described as “Transient Voltage Surge Suppressor”, comply with UL 1449, the minimum performance standard, feature an indicator light, which indicates proper functioning, and a response time that is less than 1 nanosecond.

The Joules value indicates the electrical energy the surge suppressor is capable of dissipating. This number ranges from 200 to several thousand, providing greater protection the larger the Joules value.

The clamping voltage indicates when the suppression device will conduct electricity to the ground. The typical rating is 330 volts, so do not get a surge suppressor that is greater than 400 volts.

Uninterruptible Power Supply

An uninterruptible power supply provides emergency electrical power when the power source fails, giving electrical equipment almost instantaneous protection from power interruptions. It allows sensitive equipment such as computers to be properly shut down.

Electrical Peace of Mind

Providing professional electricians since 1988 in Maryland, Cook Electric is the company you can rely on for all your electrical service needs. For knowledgeable, fair, honest, reliable, and conscientious service, call Cook Electric today at (410) 266-9040. We will be very glad to help you.