Safety Stop Function; Installation; Operation; Truth Table - WEG CFW-11 User Manual

Installation and Connection
For XC25 control cabling considers the following:
Use wire gauge from 0.5 mm
0.50 N.m (4.50 lbf.in).
Use shielded cables connected to ground only on inverter side. Use the provided metallic pieces as shown
on Figure 3.23 on page
Run the cables separated from the remaining circuits (power, 110 V / 220 Vac control, etc.).

3.3.2 Operation

3.3.2.1 Truth Table

STO1 Logic Level
(Voltage Between
XC25:1-2
Terminals)
3 0 (0 V)
0 (0 V)
1 (24 V)
1 (24 V)
NOTE!
Maximum delay between STO1 and STO2 signals: 100 ms (otherwise inverter will be tripped by F160 fault).
Safety Stop function takes priority over all other functions of the inverter.
This function should not be used as a control for starting and/or stopping the inverter.

3.3.2.2 State of Inverter, Fault and Alarm Related to Safety Stop Function

State/Fault/Alarm
STO state
F160 fault

3.3.2.3 STO Status Indication

State of the inverter is shown on the left upper side of the display and in parameter P0006.
Possible states of the inverter: ready, run (inverter enabled), undervoltage, fault, self-tuning, configuration, DC
braking and STO (Safety Stop function activated).
3-36 | CFW-11
(20 AWG) to 1.5 mm
2
3-30.
Table 3.11 - Safety Stop function operation
STO2 Logic Level
(Voltage Between Safety Stop
XC25:3-4 Function
Terminals)
0 (0 V)
Activated
(enabled)
1 (24 V)
Fault
0 (0 V)
1 (24 V) Disabled
Table 3.12 - State of inverter, fault and alarm related to Safety Stop function
Description
Safety Stop activated Voltage between terminals 1 and 2 (relay K1 coil) and between terminals 3 and 4 (relay K2 coil)
of XC25 lower than 17 V

Safety Stop function

It's applied voltage to relay K1 coil (STO1) but it's not applied voltage to relay K2 coil (STO2) or
fault vice-versa or there is a delay of more than 100 ms between one signal and the other. To solve it,
correct the external circuit that generates STO1 and STO2 signals
(14 AWG) and maximum tightening torque of maximum
2
Inverter Behavior
Inverter remains in STO state and does not accept commands. In order to escape this
condition, it's required to have STO1 = 1 and STO2 = 1 simultaneously
Inverter is tripped by F160 fault (Safety Stop function related fault). To escape this
condition, it's required to reset the inverter
Inverter accepts commands normally
Cause