Rockwell Automation 1747-L40 SLC 500 Fixed Hardware Style - Manual (Page 90)

Chapter 7
Maintaining Your Control System
7–5
Under normal power–up conditions, the POWER LED turns on. If a power
supply fuse is blown, the POWER LED will not turn on. One of the
following conditions could cause a blown power supply fuse:
•
excessive line voltage
•
internal power supply malfunction
•
overloading 2–slot chassis
!
ATTENTION: Contact with AC line potential can cause injury
to personnel. Remove system power before attempting fuse
replacement.
Use only replacement fuses of the type and rating recommended
for the unit. Improper fuse selection can result in equipment
damage.
After the conditions causing the malfunction have been corrected, you can
replace the fuse:
1. Disconnect power to the processor.
!
ATTENTION: When power is applied to the controller
hazardous electrical potentials exist under the front cover. See
page 2–8 for more information.
2. Remove the cover on the processor.
3. Locate the fuse. Use a miniature fuse puller to grip the fuse and remove it
from its holder.
4. Discard the fuse and replace it with the recommended replacement fuse.
(See chapter 9 for more information.)
Fuse
5. Replace the cover on the processor.
6. Restore power to the processor. The POWER LED should now turn on.
Replacing the Power Supply
Fuse