Safety Precautions For Sto; Safe Torque Off Installation - Danfoss VLT Midi Drive FC 280 Instruction Manual

Safe Torque Off (STO)
chapter 9.6 Control Input/Output and Control Data for the
voltage levels and input current of STO terminals.

6.1 Safety Precautions for STO

Qualified personnel
Only qualified personnel are allowed to install or operate
this equipment.
Qualified personnel are defined as trained staff who are
authorized to install, commission and maintain equipment,
systems and circuits in accordance with pertinent laws and
regulations. Additionally, the personnel must be familiar
with the instructions and safety measures described in this
manual.
NOTICE!
After installation of STO, perform a commissioning test
as specified in chapter 6.3.3 STO Commissioning Test. A
passed commissioning test is mandatory after first instal-
lation and after each change to the safety installation.
WARNING
RISK OF ELECTRICAL SHOCK
The STO function does NOT isolate AC line voltage to the
adjustable frequency drive or auxiliary circuits and
therefore does not provide electrical safety. Failure to
isolate the AC line voltage supply from the unit and wait
the time specified could result in death or serious injury.
•
Perform work on electrical parts of the
adjustable frequency drive or the motor only
after isolating the AC line voltage supply and
waiting the time specified in
chapter 2.3.1 Discharge Time.
NOTICE!
When designing the machine application, consider the
timing and distance for a coast to stop (STO). For more
information regarding stop categories, refer to EN
60204-1.

6.2 Safe Torque Off Installation

For motor connection, AC line input connection and
control wiring, follow the instructions for safe installation in
chapter 4 Electrical Installation.
Enable the integrated STO as follows:
1. Remove the jumper between control terminals 12
(24 V), 37 and 38. Cutting or breaking the jumper
is not sufficient to avoid short-circuiting. See the
jumper in Figure 6.3.
MG07A122
Instruction Manual
Figure 6.3 Jumper between Terminal 12 (24 V), 37 and 38
2.
NOTICE!
The STO signal must be PELV supplied.
Danfoss A/S © 11/2015 All rights reserved.
Connect a dual-channel safety device (for
example, safety PLC, light curtain, safety relay or
emergency stop button) to terminals 37 and 38
to form a safety application. The device must
comply with the desired safety level based on the
hazard assessment. Figure 6.4 shows the wiring
schematic of STO applications where the
adjustable frequency drive and the safety device
are in the same cabinet. Figure 6.5 shows the
wiring schematic of STO applications where
external supply is used.
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