Siemens SIMATIC ET 200SP User Manual

Wiring
3.3 Current transformer selection data
Analog input module AI Energy Meter 480VAC/CT HF (6ES7134-6PA00-0CU0)
30 Manual, 07/2018, A5E42674880-AA
Checking the ratio of burden load and power loss
The rated burden of the transformer must be 1.5 to 2 times greater than the power loss in the
connection circuit to ensure that the transformer is not overloaded and that the current
limitation is ensured during a short-circuit.
At a maximum secondary current of 4 A the power loss in the connection circuit is calculated
in accordance with the following formula for a connection cable (outgoing and incoming line)
with a length of 10 m and a cross-section of 1.0 mm
2
and a burden resistance of the
AI Energy Meter HF of 25 mΩ:
The ratio of the rated burden and the power loss in the connection circuit thus amounts to:
The required ratio of rated burden and power loss in the connection circuit lies within the
required range. The transformer is dimensioned sufficiently large.
See also
Technical specifications (Page 132)

Siemens SIMATIC ET 200SP Specifications

General

System Type	Distributed I/O System
Mounting	DIN Rail
Communication Protocol	PROFINET, PROFIBUS
IP Rating	IP20
Category	I/O Systems
Supply Voltage	24 V DC
Modularity	Yes
Hot Swapping	Yes
Storage Temperature	-40°C to +70°C
Digital Inputs	Yes
Digital Outputs	Yes
Analog Inputs	Yes
Analog Outputs	Yes
Communication Interface	PROFINET, PROFIBUS
Number of Modules	Up to 64
Relative Humidity	5 to 95% (non-condensing)
Operating Temperature	-25°C to +60°C