64 Electrical design and installation
Manual Power Quality Filter PQFS
o
The filter is disconnected from the supply or when there is no error.
−
The voltage applied to the external monitoring device will be high when:
o
The predefined error is present for the predefined time (minimum 180s)
AND
o
The external 24 Vdc power supply is in working order.
The different electrical characteristics of the digital output contacts compared to the
alarm contact characteristics must be respected. Note also that all digital outputs have
the same common which is located at the pins 1 and 2 of the right hand terminal of the
PQF-Manager (rear view, counting from top to bottom). This is clearly indicated in
A second use of the digital outputs is to monitor the status of individual master units in
a multi-filter system. This can be done by assigning the function ‘Unit missing’ (‘Unit
miss.) to a digital output. In that case the digital output of the master controlling the
complete system will activate the digital output considered when one of the units in a
filter system is not operational due to error.
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 set up and
cabled in the same way. The cabling scheme is given in
Once the cabling has been finished:
−
The auxiliary fuse box may be closed
−
The filter top cover may be replaced including the connection of the PQF-Manager
to the master unit
−
The power to the filter may then be restored
6.12.3
Cabling of warning functionality
A warning condition is a condition that can be set up by the user in such a way that if the
condition is met, a digital output contact of the PQF-Manager user interface (Cf
) is closed. As an example consider a case where the user has set up an upper warning
level for the network voltage. If the level measured by the filter becomes higher than the
predefined warning level and this condition remains valid for a preset time, the
associated digital output will be closed. By monitoring the digital output, the customer
will then know when the network voltage becomes too high and subsequently he can
take appropriate action.
Note that the warning functionality is not associated with a filter trip. It only has a
monitoring function.
describes the behavior of the digital output contact
configured as warning contact for different filter operating modes.
Table 27: State of a digital output contact configured as warning contact for different filter
operation modes
Filter state
Normally open digital contact state
Disconnected from the supply
Open
