CPU 72x
24.05.2019
page 9
1.4.2
Power Supply
The 24
Vdc power supply of the CPU 72x is realized via the 5 pole connecting terminal
(UC and 0V). Via the extension bus the internal 5
Vdc logic supply (UL) is connected to the
extension modules.
Power Supply CPU 72x
-T/LT
-TH/LTH
Power supply UC
Nominal value
24 Vdc
36 Vdc
Limit value
16.8
…30.0 Vdc 25.2…45.0 Vdc
Powerfail threshold typ.
16 Vdc
17 Vdc
Power consumption CPU without extension
modules
2.6 W
2.6 W
Max. power consumption CPU with extension
modules
11 W
11 W
Max. power supply for extension modules
5 W
5 W
Galvanic separation
UC
logic
Yes
1)
Yes
1)
UC
CAN supply
Yes
1)
Yes
1)
Logic
CAN supply
at CPU 725/727
Yes
Yes
Logic
CAN1 supply
at CPU 723-T
No
—
Logic
CAN2 supply
at CPU 723-T
Yes
—
against ground
Yes
1)
Yes
1)
Test voltage
560 Vac, 800 Vdc
Powerfail error
Yes, if UC
Powerfail threshold,
the LED ‘UC’ goes out
1)
simple insulation
Fig.08: Wiring of power supply (UC)