Sto Installation, Optional; Connecting The Signal Terminals - Grundfos CUE Series Installation And Operating Instructions Manual

6.6 STO installation, optional

DANGER
Exposure to high pressure or toxic liquids
Death or serious personal injury
- Failure to remove the jumper will disable the STO
function and the motor might not stop as intended
and can cause severe injury or death.
- Failure to use safety-monitoring relay compliant
with Category 3 /PL "d", ISO 13849-1 or SIL 2, EN
62061 and IEC 61508. Perform a functional test
every 12 months to ensure that the system works
properly.
To enable the integrated STO, follow these steps:
1. Remove the jumper wire between control terminals 37 and 12
or 13. Cutting or breaking the jumper is not sufficient to avoid
short-circuiting.
Fig. 32
2. Connect an external safety-monitoring relay via a NO safety
function to terminal 37 (STO) and either terminal 12 or 13, 24
V DC.
Select and apply the components in the safety control system
appropriately to achieve the desired level of operational safety.
Before integrating and using STO in an installation, carry out a
thorough risk analysis on the installation to determine whether the
STO functionality and safety levels are appropriate and sufficient.
FC
12
37
Fig. 33 STO wiring
Pos. Description
1 Reset button
2 Safety relay (category 3, PL d or SIL2)
3 Emergency stop button
Short-circuit protected cable if the product is not
4
installed inside an IP54 cabinet.
14
1
2
4 3
6.6.1 Restart behaviour after STO activation
By default the STO function is set to unintended-restart
prevention behaviour. To terminate STO and resume normal
operation with manual reset, do the following:
• Reapply 24 V DC supply to terminal 37.
• Send a reset signal via bus, Digital I/O or the reset button.
• Set the STO function to automatic restart by changing the
value of 5-19 terminal 37 "Safe Stop" from default value 1.
"Safe Stop Alarm" to value 3, "Safe Stop Warning".
Automatic restart means that STO is terminated, and normal
operation is resumed, as soon as the 24 V DC is applied to
terminal 37. No reset signal is required.
6.6.2 Restart settings
• Remove the 24 V DC voltage supply to terminal 37 using the
interrupt device while the frequency converter drives the
motor, that is the mains supply is not interrupted.
• Check that the motor coasts and that the alarm Safe Stop
displays in the local operating panel if mounted.
• Reapply 24 V DC to terminal 37.
• Ensure that the motor remains in the coasted state.
• Send reset signal via bus, Digital I/O or the reset button.
• Ensure that the motor becomes operational again.

6.7 Connecting the signal terminals

As a precaution, signal cables must be separated
from other groups by reinforced insulation in their
entire lengths.
Connect the signal cables according to the guidelines for good
practice to ensure EMC-correct installation. See section
6.6.1 Restart behaviour after STO
• Use screened signal cables with a conductor cross-section of
2
minimum 0.5 mm and maximum 1.5 mm
• Use a 3-conductor screened bus cable in new systems.
activation.
2
.