4.2.2 Monitoring for single-phase failure
P No.
Index Name / Setting
Unit Function
701
28
VDC_Variance
V^2
DC voltage variance
737
MON_MNCTL
Monitoring control and status word
737
0
MON_MNCTL
Monitoring control word
737
1
MON_MNSTAT
Monitoring status word
760
MON_VDC_Guard
Monitoring of DC link voltage
0
Tfilt_av
ms
Filter time constant for average
1
Tfilt_var
ms
Filter time constant for variance
2
Max_var
V^2
Max allowed variance
3
Max_time
s
Max time with variance threshold exceeded
4
Check_time
s
Interval to check return of failed phase
Table 4.8: Parameter - Single-phase failure of the device power supply
In the event of a single-phase failure of the device supply, e.g. a burned-out non-
renewable fuse, the DC link voltage is maintained and the device continues to
operate for the time being. However, the input rectifier can be damaged at a high
output power.
The single-phase power failure detection is set with P 737[0] MON_MNCTL - bit 3 =
1.
The quadratic ripple (variance) of the DC link voltage is calculated. If it exceeds the
threshold value P 760[2]-MON_VDC_Guard - MaxVar for the time P 760[3]-MON_
VDC_Guard - Max_time, the monitoring is triggered.
The actual value is shown in P 701[28] - VDC Variance. Measure this value at
maximum output power and proper operation, then use about 5-10 times that as the
monitoring threshold.
The monitoring triggers error 54-1 (Emergency code 6100h). See chapter 11.6 Error
MOOG
ID No.: CB40859-001 Date: 11/2020
MSD Servo Drive - Device Help
31
4 Power stage
If the parameter is P 737[0] MON_MNCTL, bit 4 = 1, the PowerFail state of the
control is initiated. This must therefore be configured. See chapter 4.2.1 Detection of
a voltage failure. In this case, the error reaction should be set to "Ignore".