Appendices
A - 76
NX-series Digital I/O Unit User’s Manual (W521)
Relay Output Units (Screwless Clamping Terminal Block, 12 mm 
Width)
Unit name
Relay Output Unit
Model
NX-OC2633
Number of points
2 points, independent contacts
External connection 
terminals
Screwless clamping terminal block (8 ter-
minals)
I/O refreshing method
Free-Run refreshing
Indicators
TS indicator, output indicator
Relay type
N.O. contact
Maximum switching 
capacity
250 VAC/2 A (cosΦ = 1), 250 VAC/2 A 
(cosΦ = 0.4), 24 VDC/2 A,
4 A/Unit
Minimum switching 
capacity
5 VDC, 1 mA
Relay service life
Electrical: 100,000 operations 
*1
Mechanical: 20,000,000 operations
ON/OFF response time
15 ms max./15 ms max.
Dimensions
12 (W) x 100 (H) x 71 (D)
Isolation method
Relay isolation
Insulation resistance
Between A1/B1 terminals and A3/B3 termi-
nals: 20 MΩ min. (at 500 VDC)
Between the external terminals and the 
functional ground terminal: 20 MΩ min. (at 
500 VDC)
Between the external terminals and internal 
circuits: 20 MΩ min. (at 500 VDC)
Between the internal circuit and the func-
tional ground terminal: 20 MΩ min. (at 100 
VDC)
Dielectric strength
Between A1/B1 terminals and A3/B3 termi-
nals: 2300 VAC for 1 min at a leakage cur-
rent of 5 mA max.
Between the external terminals and the 
functional ground terminal: 2300 VAC for 1 
min at a leakage current of 5 mA max.
Between the external terminals and internal 
circuits: 2300 VAC for 1 min at a leakage 
current of 5 mA max.
Between the internal circuit and the func-
tional ground terminal: 510 VAC for 1 min 
at a leakage current of 5 mA max.
Vibration resistance
Conforms to IEC 60068-2-6.
5 to 8.4 Hz with amplitude of 3.5 mm, 8.4 
to 150 Hz, acceleration of 9.8 m/s
2
100 min each in X, Y, and Z directions 
(10 sweeps of 10 min each = 100 min 
total)
Shock resistance
100 m/s
2
, 3 times each in X, Y, and Z direc-
tions
I/O power supply 
method
Supplied from external source.
Current capacity of I/O 
power supply terminal
Without I/O power supply terminals
NX Unit power con-
sumption
• Connected to a CPU Unit
1.20 W max.
• Connected to a Communications Cou-
pler Unit
0.80 W max.
Current consumption 
from I/O power supply
No consumption
Weight
65 g max.