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

Safe Torque Off (STO)

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 mains voltage to the
frequency converter or auxiliary circuits, and therefore
does not provide electrical safety. Failure to isolate the
mains voltage supply from the unit and wait the time
specified could result in death or serious injury.
•
Perform work on electrical parts of the
frequency converter or the motor only after
isolating the mains 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 mains 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 Illustration 6.3.
MG07A102
Operating Instructions
Illustration 6.3 Jumper between Terminal 12 (24 V), 37, and 38
2.
NOTICE
The STO signal must be PELV supplied.
FC 280
1 Safety device
Illustration 6.4 STO Wiring in 1 Cabinet, Frequency Converter
Provides the Supply Voltage
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. Illustration 6.4 shows the
wiring schematic of STO applications where the
frequency converter and the safety device are in
the same cabinet. Illustration 6.5 shows the wiring
schematic of STO applications where external
supply is used.
37
38
12
55
6
1
33
6