Cabling Of Alarm Functionality; Alarm Outputs - ABB PQFM Instruction Manual

6.12.2 Cabling of alarm functionality

An alarm represents an error condition that makes the filter trip. Two types of error
conditions exist:
- External error condition: These are conditions that are imposed on to the filter
from the outside world. Consider the example of the network voltage that
increases well above the filter safe operation level for a certain time. In that case
the filter will disconnect from the network reporting a network overvoltage. When
the network voltage returns to a normal level however, the filter will reconnect to
the network and continue filtering providing that the same problem does not
occur systematically.
- Internal error conditions: These are error conditions that are reported by internal
controls of the filter itself. They may indicate an internal filter problem.
Two ways to cable the alarm functionality exist:

6.12.2.1 Alarm outputs

The PQF-Manager alarm outputs located at the bottom right side (when looking at the
PQF-Manager from the rear) are triggered (return to default position) whenever:
- A permanent internal or external error condition is present. In order to avoid
transient switching of the contacts, the error has to be present for 3 minutes
before the alarm relays are activated.
- No power is supplied to the filter.
Table 30 further down this section gives an overview of all the error conditions that lead
to the alarm contact being triggered. Two alarm contacts exist, one being of type
'normally open' (NO) and the other of type 'normally closed' (NC).
The alarm contacts are:
- Free of potential.
- Rated for a maximum of 250 Vac/1.5 A or 30 Vdc/5 A. When using a
24 Vdc power supply, a minimum current of 25 mA should be drawn by the circuit
connected to the alarm contact.
Table 28 shows the status of the alarm contacts for different operation modes of the
filter.
Table 28: Status of the alarm contacts for different filter operation modes
Filter state
Disconnected from the
supply
Filter (auxiliaries)
connected to the supply,
no error present
Normally open alarm
contact state
Open
Closed
Manual Power Quality Filter PQFM ç Electrical design and installation 77
Normally closed alarm contact state
Closed
Open