Rockwell Automation 1608 HC-DySC User Manual, 200 A - Manual (Page 36)

36 Rockwell Automation Publication 1608P-UM004A-EN-P - September 2013
Chapter 6 Maintenance
Transient Voltage Surge Suppressor (TVSS)
The HC-DySC includes an internal TVSS device (or SPD), protecting the
output (load). Indicator lights on the TVSS show if surge protection is not active
(internally disconnected). Power to the TVSS module may be removed by
opening the block of fuses F16-F17-F18 and F20 (present in 4-wire models
only).