Safety Stop Function; Operation; Truth Table; State Of Inverter, Fault And Alarm Related To Safety Stop Function - WEG CFW-11 User Manual

3.3.2 Operation

3.3.2.1 Truth Table

STO1 Logic Level STO2 Logic Level
(Voltage Between (Voltage Between
XC25:1-2 XC25:3-4
Terminals) Terminals)
0 (0 V) 0 (0 V)
0 (0 V) 1 (24 V)
1 (24 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

Table 3.11 - State of inverter, fault and alarm related to Safety Stop function
State/Fault/Alarm
STO state Safety Stop activated
F160 fault

Safety Stop function

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).
It's possible to set one or more digital and relay outputs of the inverter to indicate that Safety Stop function is
activated (state of the inverter = STO), if the inverter is or not on a fault state and more specifically if the inverter
was tripped by F160 fault (Safety Stop function fault). For that use the parameters P0275 (DO1), P0276 (DO2),
P0277 (DO3), P0278 (DO4) and P0279 (DO5) according to
Table 3.10 - Safety Stop function operation
Safety Stop
Function
Activated
(enabled)
Fault
Disabled
Description
Voltage between terminals 1 and 2 (relay K1 coil) and between terminals 3 and 4
(relay K2 coil) of XC25 lower than 17 V
It's applied voltage to relay K1 coil (STO1) but it's not applied voltage to relay K2 coil
(STO2) or 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
Installation and Connection
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 1 (24 V) 0 (0 V) condition, it's required to reset the
inverter
Inverter accepts commands normally
Cause
Table 3.12 on page 3-40.
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CFW-11 | 3-39