Industrial Shields PLC 10, Manual

Page: 34 / 37

Ref. 013001000100 Rev.1: 18-01-2021
33
above and below the devices. Also, allow at least 25 cm of depth between the front of the
modules and the inside of the enclosure.
Notes for maintenance:
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.
The following factors should be considered when formulating a maintenance program:
-
Maintenance must be performed by qualified personnel familiar with the construction,
operation, and hazards involved with the control.
- Maintenance should be performed with the control out of operation and
disconnected from all sources of power.
- Care should be taken when servicing electrostatic sensitive components. The
manufacturer's recommendations for these components should be followed.
-
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.
- The means employed for grounding or insulating the equipment from ground should
be checked to assure its integrity.
- 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.
- 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.
- 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.
Safety rules for maintenance personnel
Consider the following steps to follow. A false manoeuvre could be the cause of an
accident or material damage.
Do not disassemble or modify the modules. This could lead to breakdowns or
malfunctions and could lead to injuries or fire.
- All types of radio communication devices, including mobile phones and personal
handy-phone systems (PHS), must be kept more than
25cm away from the PLC in all
directions. Failure to observe this precaution exposes malfunctions caused by excess of
temperature.
- Disconnect the external power supply of the system (on all phases) before connecting
or disconnecting a module. Failure to observe this precaution may cause faults or
malfunctions of the module.