Siemens SIMATIC ET 200SP System Manual

Distributed I/O system
295 System Manual, 09/2019, A5E03576849-AJ
Calculating the leakage resistance
C
Introduction
If you wish to protect the ET 200SP using a ground-fault detector or a residual current circuit
breaker, then you need the leakage resistance to select the correct safety components.
Ohmic resistance
When determining the leakage resistance of the ET 200SP, you must take into account the
ohmic resistance from the RC combination of the module in question:
Table C- 1 Ohmic resistance
Module
Ohmic resistance from RC network
CPU/interface module
10 MΩ (±5 %)
BaseUnit BU15...D
10 MΩ (±5 %)
BaseUnit BU30-MSx
10 MΩ (±5 %)
Formula
You can calculate the leakage resistance of the ET 200SP using the following formula if you
protect all of the modules listed above with one ground-fault detector:
R
ET200SP
=
R
module
/ N
R
ET200SP
=
Leakage resistance of the ET 200SP
R
module
=
Leakage resistance of a module
N
=
Number of BaseUnits BU15...D and interface module in the ET 200SP
R
CPU/IM
=
R
BU15...D
= R
Module
= 9.5 MΩ
R
CPU/IM
=
Leakage resistance of CP/interface module
R
BU15...D
=
Leakage resistance of the BaseUnit BU15...D
If you protect the modules listed above within an ET 200SP with several ground-fault
detectors, you must determine the leakage resistance for each individual ground-fault
detector.

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