3 repair – Rockwell Automation Safety Guidelines for the Application, Installation, and Maintenance of Solid-State Control User Manual

Page 24

Publication SGI-1.1 - August 2009

Section 5 : Preventive Maintenance and Repair Guidelines

7. Enclosures should be inspected for evidence of deterioration.

Accumulated dust and dirt should be removed from the top of the
enclosures before opening doors or removing covers.

8. Certain hazardous materials removed as part of maintenance or repair

procedure (e.g., polychlorinated biphenyls (PCBs) found in some liquid-
filled capacitors) must be disposed of as described in Federal regulations.

C.5.2 Preventive Maintenance

Lithium batteries are frequently used for memory backup in solid-state

equipment due to their excellent shelf life and high energy-to-weight ratio.

Lithium is a highly reactive metal that can cause burns if there is contact

with skin. The batteries are sealed so there is seldom a problem of contact

with lithium as long as reasonable care is exercised when handling them.

They should only be used in their intended application and not subjected

to rough handling. When batteries are replaced in equipment, the batteries

removed should be disposed of in accordance with supplier's instructions.

The Department of Transportation has certain regulations that prohibit

shipment of equipment with batteries installed if the batteries contain 0.5

gram or greater of lithium. The batteries must be removed from

equipment and shipped separately in a container approved by the

Department of Transportation. Additional Department of Transportation

restrictions apply to the shipment of lithium batteries.

NEMA Standards Publication No. ICS 1.3 - 1986, Preventive Maintenance

of Industrial Control and System Equipment, is recommended for

personnel responsible for maintenance of equipment.

5.3 Repair

If equipment condition indicates repair or replacement, the manufacturer's
instruction manual should be followed carefully. Diagnostic information
within such a manual should be used to identify the probable source of the
problem, and to formulate a repair plan. The level of field repair
recommended by the manufacturer should be followed.

When solid-state equipment is repaired, it is important that any replacement
part be in accordance with the recommendations of the equipment
manufacturer. Care should be taken to avoid the use of parts which are no
longer compatible with other changes in the equipment. Also, replacement
parts should be inspected for deterioration due to "shelf life" and for signs of
rework or wear which may involve factors critical to safety.

After repair, proper startup procedures should be followed. Special
precautions should be taken to protect personnel from hazards during startup.