What are the differences in Type 1 and Type 2 for Surge Protective Devices (SPD)?

FA164101

28 September 2021

Issue:
What is the definition of a Type 1 and Type 2 rating for Surge Protective Devices (SPD)?

Product Line:
TVSS/SPD

Environment:
Application

Cause:
Clarification

Resolution:

Type1:
Permanently connected, hard-wired SPDs which can be installed between the secondary side of the utility service transformer and the line side of the main service equipment overcurrent protective device, as well as the load side of the main service equipment.

Type2:
SPDs intended for installation on the load side of the main service equipment overcurrent protective device ONLY. These SPDs may also be installed at the service entrance point, but must be installed on the load side of the main service overcurrent protective device. 

*Note:  Check the wire range on the lugs for the SPD , ensuring that the wire size and number of conductors being connected, are within the range of the lug.