Table of Contents
Advertisement
VLT® PTC Thermistor Card MCB 112
Operating Guide
6.2.7 Warning 71, PTC 1 Safe Stop
STO has been activated from VLT
•
The MCB 112 applies 24 V DC to terminal 37 again (when the motor temperature reaches an acceptable level), and
•
The digital input from the MCB 112 is deactivated.
AUTOMATIC RESTART
When the conditions of the PTC circuit and/or emergency stop circuit have returned to normal, the motor restarts automatically.
6.2.8 Alarm 72, Dangerous Failure
STO with trip lock. If the combination of STO commands is unexpected, the dangerous failure-alarm is issued. This situation occurs if
the VLT
PTC Thermistor Card MCB 112 enables X44/10 without STO being enabled. Furthermore, if the MCB 112 is the only device
®
using STO (specified in [4] PTC 1 alarm or [5] PTC 1 warning in parameter 5-19 Terminal 37 Safe Stop), an unexpected combination
activates the STO without activating the X44/10.
If X44/10 is activated in [2] Safe stop alarm or [3] Safe stop warning, this signal is ignored. However, the MCB 112 is still able to
activate STO.
For correct and safe use of the STO function, follow the related information and instructions in the VLT
Safe Torque Off Operating Guide.
Example
[5] PTC 1 Warning is selected in parameter 5-19 Terminal 37 Safe Stop, and X44/10 is not activated, but STO is. This is an unexpected
selection. [5] PTC 1 Warning in parameter 5-19 Terminal 37 Safe Stop specifies that STO is only triggered from MCB 112.
6.2.9 Unexpected Combinations
Table 7: Unexpected Combinations Triggering Alarm 72 Dangerous Failure
Function
PTC 1 Alarm
PTC 1 Warning
PTC 1 & Relay A
PTC 1 & Relay W
PTC 1 & Relay A/W
PTC 1 & Relay W/A
+ = Activated
1
- = Not activated
2
28 | Danfoss A/S © 2022.08
PTC Thermistor Card MCB 112 (motor too warm). Normal operation can be resumed when:
®
W A R N I N G
Table 7
summarizes the unexpected combinations that trigger this alarm.
N O T I C E
N O T I C E
Number
[4]
[5]
[6]
[7]
[8]
[9]
Maintenance and Troubleshooting
X44/10 (DI)
+
(1)
-
+
-
+
+
+
+
Frequency Converter -
®
STO terminal 37
-
(2)
+
-
+
-
-
-
-
AQ267038105120en-000101 / 130R0104
Advertisement
Table of Contents
