Siemens SINAUT ST7 - Page 101

Installation guide
3.3 Current consumption and power loss of the SINAUT ST7 components
Station control system
System Manual, 07/2009, C79000-G8976-C178-07
101
Short module name Module order no. Current consumption
from backplane bus
(max.)
Current consumption
from 24 V load power
supply
Power loss (nominal)
MD741-1 6NH9 741-1AA00 - 137...182 mA ***) 4 W
MD720-3 6NH9 720-3AA00 - 50 / 140 mA **) 5 W
*) only when the TIM module is installed as a CP in an S7-300 rack
**) lower value: Receive mode/ higher value: Send mode
***) depending on the mode, see System manual MD741-1
Example
An S7-300 is configured with the following modules:
● 1 power supply PS 307; 2 A
● 1 CPU 314
● 2 digital input modules SM 321; DI 16 x DC 24 V
● 1 relay module SM 322; DO 8 x AC 230 V/5 A
● 1 analog input module SM 331; AI 8 x 12 bits
● 1 analog output module SM 332; AO 2 x 12 bits
● 1 communications module TIM 4R
● 1 modem MD3
Calculation of the current and power loss balance
The following table contains the power consumption and loss balance for the S7- 300
configuration described above. This current consumption and power loss balance does not
include any actuators connected to the outputs.
Table 3- 4 Current consumption and power loss balance
Module Current consumption
from S7-300 backplane
bus
Current consumption from 24
V load power supply
Power loss
Power supply PS 307; 2 A - - 10 W
CPU 314 - 700 mA 8 W
2 digital input modules
SM 321; DI 16 x DC 24 V
(2 x 25 mA) = 50 mA (2 x 25 mA) = 50 mA (2 x 3.5 W) = 7 W
1 relay module
SM 322; DO 8 x AC 230 V/5 A
40 mA 125 mA 4.2 W
1 analog input module
SM 331; AI 8 x 12 bits
60 mA 200 mA 1.3 W
1 analog output module
SM 332; AO 2 x 12 bits
60 mA 135 mA 3 W
1 communications module
TIM 4R
60 mA 500 mA 12.3 W
1 modem MD3 - 200 mA 4.8 W
Total: 270 mA 1910 mA 50.6 W