Type 1 SPDs offer first line defense against
external surges. They use the largest MOV’s in the business
(40mm & 53mm) and are outdoor rated. Plus, some of Type 1
SPDs feature an audible alarm warning that the device is no
longer providing the rated surge protection.
Type 2 surge panels use UL-recognized surge
fuses and contain replaceable modules, surge counters and
7-Mode protection. These SPDs conform to NEMA LS 1
guidelines.
Type 3 meets point-of-use applications.
Type 4 SPDs are UL recognized components,
and are available in a variety of configurations, including
DIN rail mount, wall mount and leaded.