4
Operating instructions
Safety relay module
SRB 301MC
SRB 301MC-ST
EN
5.3 Notes
Signalling outputs must not be used in safety circuits.
Due to the operating principle of the electronic fuse, the cus-
tomer must check that no hazard is caused by an unexpected
restart in circuits without reset button (automatic reset).
Opening the front cover (see Fig. 2)
• To open the front cover, insert a slotted screwdriver in the top and
bottom cover notch and gently lift it.
• When the front cover is open, the electrostatic discharge requirements
must be respected and observed.
• After setting, the front cover must be fitted back in position.
Only touch the components after electrical discharge!
Setting the switch (see Fig. 3)
• The cross-wire short monitoring function (factory setting) is
programmed by means of the switch underneath the front cover of the
safety-monitoring module.
• The switch must only be operated in de-energised condition by means
of a finger or an insulated blunt tool.
• Pos. nQS (top): Not cross-wire short proof,
suitable for 1-channel applications with outputs connected to potential
in the control circuits.
• Pos. QS (bottom), Cross-wire short proof:
suitable for 2-channel applications without outputs connected to
potential in the control circuits.
U
B
U
i
K1
K2
SRB
301
S11 13 23 33
S12 14 24 34
S21 42 X2 A2
S22 41 X1 A1
U
B
U
i
K1
K2
SRB
301
S11 13 23 33
S12 14 24 34
S21 42 X2 A2
S22 41 X1 A1
U
B
U
i
K1
K2
SRB
301
S11 13 23 33
S12 14 24 34
S21 42 X2 A2
S22 41 X1 A1
S12 18 28 38
S22 45 X1 A1
nQS
QS
Fig. 1
Fig. 2
Fig. 3
6. Set-up and maintenance
6.1 Functional testing
The safety function of the safety-monitoring module must be tested.
The following conditions must be previously checked and met:
1. Correct fixing
2. Check the integrity of the cable entry and connections
3. Check the safety-monitoring module's enclosure for damage.
4. Check the electrical function of the connected sensors and their
influence on the safety-monitoring module and the downstream
actuators
6.2 Maintenance
A regular visual inspection and functional test, including the following
steps, is recommended:
1. Check the correct fixing of the safety-monitoring module
2. Check the cable for damages
3. Check electrical function
If a manual functional check is necessary to detect a
possible accumulation of faults, then this must take place
during the intervals noted as follows:
• at least every month for PL e with category 3 or
category 4 (according to ISO 13849-1) or SIL 3 with HFT
(hardware fault tolerance) = 1 (according to IEC 62061),
• at least every 12 months for PL d with category 3
(according to ISO 13849-1) or SIL 2 with HFT (hardware
fault tolerance) = 1 (according to IEC 62061).
Damaged or defective components must be replaced.
7. Disassembly and disposal
7.1 Disassembly
The safety-monitoring module must be disassembled in a de-energised
condition only.
Push up the bottom of the enclosure and hang out slightly tilted
forwards.
7.2 Disposal
The safety-monitoring module must be disposed of in an appropriate
manner in accordance with the national prescriptions and legislations.
