Omron NT631C manual Inspection Method, Items Required for The Inspection, Points Inspected

Inspection and Cleaning				Section 7-4
Inspection Method		In normal environments, inspect the NT631/NT631C 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 The Inspection
		Prepare the following items before starting the inspection.
		• 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)
		Points Inspected
		Inspect the following points to determine if there is any divergence from the
		stated criteria. If there is, either improve the surrounding environment so that
		the values fall within the stated range, or adjust the NT631/NT631C, for exam-
		ple by re-tightening screws.
Point	Inspection Details		Criterion	Inspection
Inspected				Instrument
Power supply	Fluctuation in power supply terminal		Permissible voltage fluctuation range	Tester
voltage	voltage		20.4 to 26.4 VDC (24 VDC –15% to
			+10%)
Ambient envi-	Ambient temperature (temperature in		0 to 50°C	Thermometer
ronmental con-	the operation panel)
ditions
	Ambient humidity (humidity in the		35% to 85% RH	Hygrometer
	operation panel)
	Presence/absence of dust		Dust must not be settled	Visual inspection
Mounting condi-	Looseness of mounting brackets, etc.		To be no looseness	Phillips screwdriver
tions
	Connector connections of connecting		To be fully inserted and locked, with no	Phillips screwdriver
	cable		looseness
	Looseness of screws in external wir-		To be no looseness	Phillips screwdriver
	ing
	Conditions of external connecting		Faults such as incipient disconnection	Visual inspection
	cables
Components	Brightness of the backlight		Must be sufficiently bright.	Visual inspection
with limited lives	(NT631C only)		Backlight life:
			(Under the normal range of ambient tem-
			perature and humidity)
			NT631C-ST141@-EV2: Approx.
			25,000 hours or longer
			NT631C-ST151@-EV2: Approx.
			30,000 hours or longer
			NT631C-ST152@-EV2/ST153@-EV3:
			Approx. 50,000 hours or longer
			(Brightness setting is not available for
			the NT631C-ST151/152@-EV2/
			ST153@-EV3 and the backlight can-
			not be replaced.)
	Note	1. Do not disassemble for repairs or modification.

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