ABB PQFS Installation, Operation And Maintenance Instructions page 59

the filter is interrupted or the filter trips due to an error. Otherwise the bulb will be
off.
PQF-Manager
NO
Alarm
outputs
Remark:
(a)
Right hand terminal block when looking from rear, counting from top to
Figure 51: 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
for 2 master filters.
230 Vac
external
power
supply
Note: Contacts drawn in non-alarm position
Figure 52: Cabling of the alarm status of a multi-unit filter consisting of masters only, using the NC
In the Figure 52, the alarm bulb will be activated when both master units are in
alarm.
Figure 53 shows a cabling scheme using a 24 Vdc supply in conjunction with the
NO alarm contact. The scheme assumes that an external digital input monitors
the alarm contact of the filter. In this case the voltage applied to the digital input
will be low when:
the filter is disconnected from the supply OR
o
the filter trips due to an error OR
o
the external 24 Vdc power supply fails
o
The voltage applied to the external digital input is high when:
the filter is connected to the supply and is not in error AND
o
the external 24 Vdc power supply is in working order
o
9
External bulb
10
alarm indicator
(a)
11
NC
(a)
12
NC Alarm
contact of
master 1
alarm contact on each filter.
Manual Power Quality Filter PQFS ç Electrical design and installation 59
230 Vac
external
power
supply
B
NC Alarm
contact of
Alarm bulb
master 2
B
Figure 52