Manual Power Quality Filter PQFS  Electrical design and installation 65
Filter (auxiliaries) connected to the
supply, no warning present
Open
Filter (auxiliaries) connected to the
supply, predefined warning present
Closes when warning present for pre-defined time.
Otherwise, contact remains open.
Filter (auxiliaries) connected to the
supply, predefined warning disappears
When closed before and warning disappears for at
least the predefined time, contact opens.
When closed before and warning disappears for a
time smaller than predefined time, contact
remains closed.
Otherwise, contact remains open.
Table 28 gives a list of the warning conditions that can be assigned to a digital output.
Table 28: List of possible warning conditions that can be assigned to a digital output
Supply voltage (RMS) higher than preset value.
Supply voltage (RMS) lower than preset value.
Supply voltage imbalance higher than preset value.
Ground current level higher than preset value.
IGBT Temperature higher than preset value.
Control board temperature higher than preset value.
Remark: All warning levels can be changed by the user.
Any of the six digital outputs can be used to cable warning functionality. A maximum of
3 warnings can be assigned to the digital outputs. However, by default the digital
outputs of the PQF-Manager have been set up for monitoring other functions than
warnings (cf. Table 10). Refer to Section 7.9.1.4 for guidelines on how to set up warning
conditions and how to associate them with digital output contacts.
For cabling the digital output contacts as warning contact, the same approach as shown
in Figure 44 can be adopted. The electrical characteristics of the digital output contacts
and the points to pay attention to are discussed in Section 6.12.2.
In order to obtain full redundancy with filters consisting of more than one master unit,
the digital outputs of all the units in a multi-master arrangement have to be set up and
cabled in the same way. The wiring diagram given in Figure 45 can be used to implement
the monitoring of the warnings in multi-master units.
6.12.4 Cabling of the digital output contacts to monitor other filter operation
modes than warnings and alarms
Table 9 gives an overview of the other functions that can be monitored with the digital
outputs in addition to the already discussed warnings and alarms.