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Maintenance of the NT20
Section 7-3
7-3
Maintenance of the NT20
Carry out maintenance work in order to ensure that the NT20 is always used
in its optimum condition.
!WARNING
Do not attempt to take the PLC apart and do not touch any internal parts while
the power is being supplied. Doing either of these may result in electrical
shock.
Spare PT
It is advisable to have a spare NT20 available to minimize system downtime in
the event of an NT20 failure or if the screen display becomes difficult to read
due to deterioration of the display unit.
Backlight
The backlight must be replaced when the brightness of the display backlight
dims and the display becomes difficult to see. The backlight cannot be
replaced by the user.
Contact your nearest OMRON representative.
7-4
Inspection and Cleaning
Clean and inspect the NT20 regularly to ensure that it is always used in its
optimum condition.
Cleaning Method
If the display is dirty the screen is difficult to see. Clean the screen from time
to time as follows.
• In daily cleaning, wipe the display with a soft dry cloth.
• If the soiling cannot be removed with a dry cloth, wet the cloth with water,
wring it out well and wipe the display with it.
• If rubber or vinyl products, tape, etc. are left stuck to the display for long
periods they will cause staining. If such items are stuck to the display,
remove them during cleaning.
Note
Never use volatile solvents such as benzene or thinners, or dusters.
Inspection Method
In normal environments, inspect the NT20 at intervals of between 6 months
and a year. In environments that are extremely hot and humid, or very dusty
environments, shorten the inspection interval.
• Items Required for Inspection
Prepare the following items before starting the inspection.
• The tools supplied with the NT20
• Screwdrivers (Phillips, flat-head)
• Tester (or digital voltmeter)
• Industrial alcohol
• 100% cotton cloth
• Hygrometer (required in some cases)
• Thermometer (required in some cases)
• Synchroscope (required in some cases)
• Pen-writing oscilloscope (required in some cases)
Summary of Contents for NT20
Page 1: ...Programmable Terminal Cat No V091 E1 01 NT20 USER S MANUAL ...
Page 2: ...NT series Programmable Terminal User s Manual Produced March 2007 ...
Page 3: ...iv ...
Page 5: ...vi ...
Page 9: ...x TABLE OF CONTENTS ...
Page 15: ...xvi ...
Page 21: ...xxii EC Directives 6 ...
Page 37: ...16 Before Operating Section 1 6 ...
Page 153: ...132 Transferring the Resource Data Section 3 11 ...
Page 185: ...164 Numeral Setting Section 4 8 ...
Page 267: ...246 Key to Programs Section 6 8 ...
Page 281: ...260 Specifications Appendix A ...
Page 285: ...264 Transporting and Storing PTs Appendix C ...
Page 303: ...282 Function Restrictions Depending on the Support Tool Appendix I ...
Page 307: ...286 Index ...
Page 309: ...288 Revision History ...