Calculating Unit Current Consumption - Omron CJ2 User Manual

2 Basic System Configuration and Devices
2-1-5

Calculating Unit Current Consumption

The amount of current/power that can be supplied to the Units mounted in a Rack is limited by the
capacity of the Rack's Power Supply Unit. Refer to the following tables when designing your system so
that the total current consumption of the mounted Units does not exceed the maximum current for each
voltage group and the total power consumption does not exceed the maximum for the Power Supply
Unit.
For details on calculating the current consumption of Units, refer to 2-1-2 CPU Rack, 2-1-3 Expansion
Racks, and 2-1-4 Configuration Units.
Maximum Current and Power Supplied by Power Supply Units
The following table shows the maximum currents and power that can be supplied by Power Supply
Units in CPU Racks and Expansion Racks.
Note 1 When calculating current/power consumption in a CPU Rack, be sure to include the power required by the
CPU Unit itself, as well as the I/O Control Unit if one or more Expansion Racks is connected.
2 Be sure to include the power required by the I/O Interface Unit when calculating current/power consump-
tion in an Expansion Rack.
Power Supply Unit
CJ1W-PA205R
CJ1W-PA205C
CJ1W-PA202
CJ1W-PD025
CJ1W-PD022
Example Calculations
Example 1: In this example, the following Units are mounted to a CPU Rack with a CJ1WPA205R
Power Supply Unit.
Unit
CPU Unit
I/O Control Unit
Input Units
Output Unit
Special I/O Unit
CPU Bus Unit
Current consump-
tion
Power consump-
tion
2-18
Max. current consumption
5-V group
(internal logic)
5.0 A 0.8 A
5.0 A 0.8 A
2.8 A 0.4 A
5.0 A 0.8 A
2.0 A 0.4 A
Model Quantity
CJ2H-CPU68-EIP 1
CJ1W-IC101 1
CJ1W-ID211 2
CJ1W-ID231 2
CJ1W-OC201 2
CJ1W-DA041 1
CJ1W-CLK23 1
Calculation
Result
Calculation
Result
24-V group 24-V group
(relays) (service)
None
None
None
None
None
Voltage group
5-V
0.820 A
0.020 A
0.080 A
0.090 A
0.090 A
0.120 A
0.350 A
0.820 A + 0.020 + 0.080 ×
2 + 0.090 × 2 + 0.090 × 2 +
0.120 + 0.350
1.83 A (≤5.0 A)
2.51 × 5 V = 9.15 W
9.15 + 2.30 = 11.45 W (≤25 W)
CJ2 CPU Unit Hardware User's Manual
Max. total power
consumption
25 W
25 W
14 W
25 W
19.6 W
24-V
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0.048 A
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0.048 × 2
0.096 A (≤0.8 A)
0.096 A × 24 V = 2.304 W