Do Emergency Power Generators Require The Use Of Surge Protectors?

For home applications, the event of transferring the home power source from the utility to a generator can create an electrical voltage spike and the generator itself could be a source of spikes and surges. Home emergency generator manufacturers do consider this possibility and most manufacturers include a surge protective device to the output of that generator.

For commercial and industrial applications, No, not every industrial emergency power generator is required to have a surge protector. However, many emergency power systems are required by NEC to include Surge Protective Devices (SPDs) at specific points in the system, and installing them is generally considered a best practice. The code requirement applies to the emergency power distribution equipment rather than the generator alternator itself. However, SPDs are frequently installed:
- At the generator output terminals
- On the generator distribution switchboard
- At the Automatic Transfer Switch (ATS)
- At downstream panels serving sensitive loads
- On control and communication circuits

In both cases, for emergency systems governed by the National Electrical Code (NEC) Article 700, a listed SPD must be installed on emergency system switchboards, switchgear, and panelboards. The requirement is intended to protect life-safety equipment from transient overvoltages caused by lightning, utility switching, generator transfers, and similar events.

Released for: Schneider Electric Canada