Notes On The Protective Circuitry Of External Relays And Contactors (Free-Wheeling Circuit); Measures To Meet A Certain Safety Integrity - Bosch Rexroth IndraControl S20 Manual

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Connection examples of the safe outputs
7.2 Notes on the protective circuitry of external relays and con‐
tactors (free-wheeling circuit)
7.3

Measures to meet a certain safety integrity

IndraControl S20 Module With Safe Digital Outputs S20-SSDO-8/3
The following is specified for each example:
● Key data
The table provides the important data for the example.
● Device diagnostics and module behavior in case of error
The diagnostic capability depends on the parameterization.
If an error message is transferred to the control, the respective message
is provided in the table. For information on the error code, the trouble‐
shooting options and whether the error message has to be acknowl‐
edged, refer to chapter 9 "Errors: Reporting and troubleshooting" on
page 43.
● Example parameterization
The table exemplarily shows all parameters for the specified assign‐
ment.
Representation Meaning
Bold Mandatory setting
Normal Exemplary setting. Depending on the application, another setting is
possible.
- Is not evaluated
Tab. 7-1: Key for the following tables
Faults (cross-faults. short circuits) that can be excluded if the installation is
correct (e.g. protected cable routing, separated cable routing, double insula‐
tion, use of ferrules) are not considered in the table.
Only errors between outputs located on the same plug are observed. If the
installation is correct, cross-faults against inputs and outputs of other plugs
for example cannot occur.
Fig. 7-1: Example of the free-wheeling circuit of an external relay
Observe the following measures:
● Limit the inductive switch-off voltage to < –15 V (e.g. with RC elements,
suppressor diodes or varistors).
● Note that the free-wheeling circuit affects the release time and the serv‐
ice life of the contactor.
● Note the vendor specifications while dimensioning the protective circui‐
try of the relay.
The attainable safety integrity (SIL, SILCL, category und performance level)
is specified for each connection example.
DOK-CONTRL-S20*SSDO*8*-AP02-EN-P
K1