60 Electrical design and installation
Manual Power Quality Filter PQFS
shows the status of the alarm contacts for different operation modes of the
filter.
Table 24: Status of the alarm contacts for different filter operation modes
Filter state
Normally open alarm
contact state
Normally closed alarm contact state
Disconnected from the
supply
Open
Closed
Filter (auxiliaries)
connected to the supply,
no error present
Closed
Open
Filter (auxiliaries)
connected to the supply,
error appears
Opens when error
present for 3 minutes
Otherwise, remains
closed
Closes when error present for 3
minutes
Otherwise, remains open
Filter (auxiliaries)
connected to the supply,
error disappears
When open before,
closes when error
disappears
When closed before,
remains closed
When closed before, opens when error
disappears
When open before, remains open
shows an example of an alarm contact cabling scheme using the NC alarm
contact. Using this scheme the bulb B will be on when the power supply to the filter is
interrupted or the filter trips due to an error. Otherwise the bulb will be off.
15
16
(a)
17
(a)
PQF-Manager
Alarm
outputs
NO
NC
230 Vac
external
power
supply
External bulb
alarm indicator
B
Remark:
(a)
Right hand terminal block when looking from rear, counting from top to
Figure 42: Alarm bulb cabling scheme using the NC alarm contact on
the PQF-Manager
When the filter system consists of multiple master-units and an alarm contact is needed
to signal when the complete system is off, then the NC alarm contacts of all the master
units have to be cabled in series. An example is given in