Rockwell Automation Safety Guidelines for the Application, Installation, and Maintenance of Solid-State Control - Manual (Page 25)

Publication SGI-1.1 - August 2009
Section 5 : Preventive Maintenance and Repair Guidelines 25
Too much pressure against a heatsink can damage a semiconductor while
too little can restrict the amount of heat transferred from the
semiconductor to the heatsink and result in operation at higher
temperature with decreased reliability.
Exercise care when removing modules from a system during maintenance.
Failed modules are frequently returned to the manufacturer for repair. Any
physical damage sustained during removal may result in more expensive
repair or render the module unrepairable if damage is too great.
Modules with electrostatic sensitive components should be handled by the
edges without touching components or printed circuit conductors. Use
packaging material supplied with the replacement module when shipping
the module to the manufacturer for repair.
When the scope of repairs exceeds the manufacturer's recommendations
for field repair, the module(s) should be returned to the manufacturer for
repair. Doing so will help to ensure that only properly selected
components are used, and that all necessary hardware and firmware
revisions are incorporated into the repair. Failure to make necessary
updates may result in safety, compatibility or performance problems which
may not become apparent for some time after the repaired module has
been placed back in service. When firmware is protected by copyright law,
updates can be provided legally only by the manufacturer or licensee.
See also section 4.3.
5.4 Safety Recommendations
for Maintenance Personnel All maintenance work should be done by qualified personnel familiar with the
construction, operation, and hazards involved with the equipment. The
appropriate work practices of NFPA 70E should be followed.