The 2020 NEC updates require surge protection for most
electric applications. Installing surge protection is something that many home
inspectors already recommend. We will look at the different types and the
proper installation of surge protectors. A “surge” is a very brief surge of
voltage on the electrical lines. A surge can be caused by work the utility
company may be performing, power outages, turning a breaker on and off, devices
/ appliances with large power draws, and a lightning strike.
A surge can cause damage to many sensitive electrical
devices and appliances that have a motor. There are 4 types of surge protection
devices. Type 1 is installed at the line side of the main electric service
panel between the utility pole / transformer and where the electric conductors
enters your service panel. Type 1 protect against external power surges, but do
not offer protection against internally surges. You would see this device at
the meter. Type 2 surge protectors are installed on the load side of the main
service panel and will protect against external and internal power surges. This
unit can be directly connected to the main service panel. It will look like a
double pole breaker with no handle. A neutral stranded conductor from the surge
protector will be connected to the neutral bus. Green conductor would go to the
ground bus. This is for installation in a main service panel and is normally
closest to the main service disconnect or the main service lug. An external surge protection device is
installed either next to or directly on the outside of the main service panel.
Two black / hot conductors will be connected to a double pole circuit breaker
closest to the main service disconnect or the main service lug. The size of the
breaker is determined by the manufacture. I see many that are rated for 20
amps. This can easily be looked up to ensure it is properly installed. A white
or neutral conductor is connected to the neutral bus, green to the ground. Type
3 surge protection devices are located at the devices. Surge protective
receptacles can be installed in place of a typical receptacle. The wiring is
the same. Surge power strips can also be used for protection. They should not
be confused with a power strip that does not contain surge protection. Type 4
surge protectors are surge protection modules for industrial applications. They
can also be directly wired in. In addition, they will protect industrial
devices that use servo motors and automation drives.
