22 | Installation
Power Quality Controller – PQC | Operating Manual | FRAKO
5.2.3 Specifications for the electrical connections
– Only approved solid core or stranded wire cables having an adequate cross sec-
tion and sufficiently high voltage withstand ratings must be used for the connect-
ing cabling.
– If flexible stranded cables are used for the PQC connections, short ferrules 6 mm
in length must be crimped onto their ends.
– Suitable clips or other fasteners must be fitted to relieve any strain on the wires
and cables connected to the PQC.
– No additional connectors must be fitted in the wires and cables connected to the
PQC.
– All the connectors supplied with the PQC must be plugged in, even when it is
not intended to use them, and be secured to the instrument with their retaining
screws, if provided.
5.2.4 Earth connection
An earthing tab is provided for the PE connection in the rear wall of the
casing. It is marked with the earthing symbol as per EN 60617-2 shown
at left
The PE conductor cross section must be at least equal to that of the larg-
est conductor of the AUX phases, the voltage measurement connections,
the relay outputs or the alarm connections. Its insulation colour is yellow/
green. Earthing connections for network power circuits must have at least
the same current-carrying capacity rating as the circuits themselves.
If the earthing tab has broken off, the PQC must not be started up. The
instrument must either be repaired or replaced.
Note
The PQC may only be put into service if the earthing conductor is con-
nected to it.
5.2.5 Power supply
External disconnector
An external disconnecting device, such as an isolator or circuit breaker, must be
fitted in the power supply line to the PQC. This must be located in the vicinity of the
instrument and must be able to isolate all cables connected to the AUX terminals of
the PQC. This device must not disconnect the earthing conductor.
