Preventive Maintenance; Table 6-1 Inspection Items - Hitachi HSC-2100 Hardware Manual

6 MAINTENANCE

6.1 Preventive Maintenance

Every I/O module in a programmable controller should be given a daily or periodical (two or
more times a year) inspection on the inspection items listed below.
The purpose of these inspections is to keep the I/O modules in an optimal condition and thereby
ensure the problem-free use of the modules.
No.
① External appearance of each module
Lighting condition of each indicator or similar device
②
Loosened fixing screws, terminal block screws, and connector fastening
③
④ Condition of cable and wire jackets
Accumulation of dust and dirt
⑤
Input voltage to power supply
⑥
⑦ Voltage of power supply (power supply module and external power sources)
Remaining service life of relay contacts
⑧
Do not touch any of the modules in the programmable controller when they are
in an energized state. Touching any of the modules in an energized state
may lead to a discharge of static electricity from your body to the module,
resulting in malfunction or breakage of the module. If you have no choice but
to touch such a module, be sure to discharge the static electricity by touching
the metal frame of the cubicle and then touch the module. This is also true
when you perform any of the following actions on a module in its non-
energized state: 1) setting a switch on the module; 2) connecting or
disconnecting the cable from the module; or 3) inserting or removing the
connector from the module.
Every fixing or terminal screw must be secured tightly.
Insufficiently tightened screws may result in malfunction, smoke, or fire.
① External appearance of each module
Check each module for any trace of crack or flaw in its casing.
The presence of any such condition indicates that the internal circuitry may be damaged.
Such damage may result in system malfunction.
② Lighting condition of each indicator or similar device
Check each indicator or similar device for any abnormal lighting condition.
③ Loosened fixing screws, terminal block screws, and connector fastening
Before performing an inspection for this inspection item, be sure to power down your
application system.
Under this inspection item, check each module to see if any fixing screws, terminal block
screws, and connector fastening are loosened.
If a loosened screw or fastening is found, secure them tightly.
Any loosened screw may result in system malfunction or burnout due to heat buildup.

Table 6-1 Inspection Items

Item
NOTICE
6-2