Siemens simatic et200sp User Manual

Wiring
3.3 Current transformer selection data
Analog input module AI Energy Meter 480VAC ST (6ES7134-6PA20-0BD0)
24 Manual, 12/2015, A5E36061895-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 Energy
Meter 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 92)

Siemens simatic et200sp Specifications

General

Category	I/O Systems
Power Supply	24 V DC
Protection Rating	IP20
Number of Modules	Up to 64 modules
Mounting	DIN Rail
Communication Protocols	PROFINET, PROFIBUS
Storage Temperature	-40 °C to +70 °C
Digital Inputs	Yes (depending on module)
Digital Outputs	Yes (depending on module)
Analog Inputs	Yes (depending on module)
Analog Outputs	Yes (depending on module)
Modularity	Modular
Relative Humidity	5 to 95% (non-condensing)
Weight	Varies by configuration
System Type	Distributed I/O