FAQ
42
new and significant change from the previous 
2020 NEC language.
Leviton Solution 
Type 2 Surge Protection Devices (SPDs) would typically 
be the type of device most often associated with this 
Code article. See Type 2 Below.
Here we have provided an explanation of the dierent levels of 
surge protection and their applications:
continued from page 40
Type 3 SPDs are typically 
surge receptacles or cord 
connected point-of use 
devices. Leviton oers a 
complete assortment 
in duplex and quad in many 
styles and colors.
Surge Receptacles 
and Strips
Type 2 SPDs are typically service 
entrance SPD panels or branch 
circuit SPD panels that are 
connected on the load side of 
the service disconnect overcurrent 
device (main service panel).
Type 1 SPDs for the supply side of 
service entrance.
Surge 
Breakers
Cat. No. 
51120
Cat. No.
51110-SGR
Type 1 and Type 2 SPDs shunt external surges that originate from 
utilities or disturbances outside the home or facility. Type 2 SPDs 
can protect for both internal and external surges when located at 
the branch. Type 3 SPDs can shunt surges that originated internally 
within the home or facility. So a comprehensive strategy for surge 
protection typically involves a Type 1 or Type 2 SPD and also a 
Type 3 SPD at point of use.
Type 4 SPDs are component 
assemblies consisting of one or 
more Type 5 components 
together with a disconnect 
(integral or external) or a means 
of complying with the limited 
current tests in UL 1449.
Type 5 SPDs Discrete component 
surge suppressors connected 
by its leads or provided with an 
enclosure with mounting means 
and wiring terminations.










