Rockwell Automation Safety Guidelines for the Application, Installation, and Maintenance of Solid-State Control - Manual (Page 23)

Publication SGI-1.1 - August 2009
Section 5 : Preventive Maintenance and Repair Guidelines 23
Section 5 : Preventive Maintenance and
Repair Guidelines
5.1 General A well-planned and executed maintenance program is essential to the
satisfactory operation of solid-state electrical equipment. The kind and
frequency of the maintenance operation will vary with the kind and complexity
of the equipment as well as with the nature of the operating conditions.
Maintenance recommendations of the manufacturer or appropriate product
standards should be followed.
Useful reference publications for setting up a maintenance program are NFPA
70B-1983, Maintenance of Electrical Equipment, and NFPA 70E-1983,
Electrical Safety Requirements for Employee Workplaces.
5.2 Preventive Maintenance The following factors should be considered when formulating a maintenance
program:
1. Maintenance must be performed by qualified personnel familiar with the
construction, operation, and hazards involved with the control.
2. Maintenance should be performed with the control out of operation
and disconnected from all sources of power. If maintenance must be
performed while the control is energized, the safety related practices of
NFPA 70E should be followed.
3. Care should be taken when servicing electrostatic sensitive components.
The manufacturer's recommendations for these components should be
followed.
4. Ventilation passages should be kept open. If the equipment depends
upon auxiliary cooling, e.g., air, water, or oil, periodic inspection (with
filter replacement when necessary) should be made of these systems.
5. The means employed for grounding or insulating the equipment from
ground should be checked to assure its integrity (see 4.5).
6. Accumulations of dust and dirt on all parts, including on semiconductor
heat sinks, should be removed according to the manufacturer's
instructions, if provided; otherwise, the manufacturer should be
consulted. Care must be taken to avoid damaging any delicate
components and to avoid displacing dust, dirt, or debris in a way that
permits it to enter or settle into parts of the control equipment.