Omron NX701-1620, User Manual

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6 Inspection and Maintenance
6 - 6 NX-series CPU Unit Hardware User’s Manual (W535)
6-2 Replacing the Battery
The Battery in the NX-series CPU Unit must be replaced periodically as preventative maintenance.
(The Battery is a backup power supply for the CPU Unit’s internal clock and the variables that are
retained during power interruptions.) This section describes how to replace the Battery.
The Battery maintains the CPU Unit internal clock and the variables retained during power interruptions
while the main power supply is OFF.
If the Battery is not installed or Battery voltage drops too low, the internal clock will stop and the vari-
ables that are retained for power interruptions will be lost when the main power supply goes OFF.
The service life of a Battery is five years, which varies depending on the CPU Unit model, ambient tem-
perature, and power ON time rate.
Make a plan to replace the Battery so that the service life of the Battery will not exceed the minimum
lifetime under the normal product usage condition.
The Battery service life when power ON time rate is 0% (i.e., power OFF)
Battery service life (minimum lifetime) of NX701-

in relation to
power ON time rate and ambient temperature
6-2-1 Battery Replacement
Purpose of the Battery
Battery Service Life and Replacement Period
Unit model number
Approx. minimum lifetime [month]
*1
*1. The minimum lifetime we warrant is based on the calculation with the worst case values within the
specifications for the parts used in the product.
Reference life-
time [month]
*2
*2. The lifetime is based on the calculation with test data of the product. This value is used only for
reference because deviation for individual model is not considered.
25°C 40°C 55°C 25°C
NX701-

31 17 10 60
0
10
20
30
40
50
60
0 25 50 75 100
Service life [month]
Power ON time rate [%]
Ambient temperature
55
°
C
25
°
C
40
°
C
31
17
10
40
22
13
55
32
57
32
18