Precautions When Using The Relay Output Units - Omron NX-ID User Manual

7 Digital Output Units
7-6 Precautions when Using the Relay
Output Units
This section describes precautions when using the Relay Output Units.
Relay Service Life
The service life of Relay Output Units depends on the type of load, contact current and ambient tem-
perature.
Use the following diagrams to calculate the relay service life based on the operating conditions, and
replace the NX Unit before the end of its service life.
Contact Current vs. Service Life Characteristic
500
300
200
100
50
30
20
10
5
3
2
1
0.1
Switching frequency: 20 operations/minute
Precautions for Correct Use
The above chart shows the life characteristics for individual relays. Do not exceed the specifi-
cations of the Relay Output Units. If a switching capacity exceeding the specifications is used,
the reliability and life expectancy of other parts will be reduced and the NX Unit may malfunc-
tion.
7 - 20
Service life curve
24 VDC/250 VAC
Resistance loads
24
VAC
0.2 0.3 0.5 1 2 3
Contact current (A)
5 10
NX-series Digital I/O Unit User's Manual (W521)