Rockwell Automation 1746-XXXX SLC 500 Digital I/O Modules Installation Instructions - Manual (Page 14)

14 SLC 500 Digital I/O Modules
Publication 1746-IN027D-EN-P - December 2012
Replace Fuses
1. Remove SLC 500 system power and correct the conditions causing the short circuit.
2. Remove the output module from the chassis.
3. Remove the fuse.
• 1746-OBP16 and 1746-OVP16 modules: Use a wide-tipped, slotted-head
screwdriver to remove the blown fuse. Slide the screwdriver tip under the fuse and
use a twisting motion to pry the fuse from the fuse clip. Use care so that the printed
circuit board and surrounding electronics are not damaged.
• 1746-OAP12 module: A fuse holder is provided with each fuse. Simply grasp the
fuse holder with needle-nose pliers, or your fingers, and pull it out.
4. Replace the fuse.
• 1746-OBP16 and 1746-OVP16 modules: Center the replacement fuse over the fuse
clip and press down. If you use a tool to press the fuse in place, apply pressure to the
metal end caps only, not the center of the fuse.
• 1746-OAP12 module: Insert a new fuse into the fuse holder, align the fuse holder on
fuse clips, and press down.
5. Replace the output module in the chassis.
6. Restore SLC 500 system power.
7. Clear processor fault bits as indicated in the steps provided on
page 13 .
Electronically Protected Modules (1746-OB6EI and 1746-OB16E)
The electronic protection of the 1746-OB6EI and 1746-OB16E modules have been designed to
provide protection for the modules from short circuit and overload current conditions. The
protection is based on a thermal cut-out principle. In the event of a short circuit or overload
current condition on an output channel, that channel will limit current within milliseconds after
its thermal cut-out temperature has been reached. All other channels continue to operate as
directed by the CPU (processor) module.
ATTENTION: Never install, remove, or wire modules with power applied to chassis.
IMPORTANT The modules do not provide protection against reverse polarity wiring or
wiring to ac power sources. Electronic protection is not intended to replace
fuses, circuit breakers, or other code-required wiring protection devices.