F20
Twin Earth Fault Indicator
© Nortech Management Ltd, United Kingdom
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Description
The F20 Twin Earth Fault Indicator enables electricity distribution network
engineers to quickly determine which section of the underground MV network
is responsible for the interruption of consumer supplies.
The F20 has two independent Earth Fault (EF) elements. This allows the F20
to be used to monitor both the incoming and outgoing cables at a Ring Main
Unit site on the distribution network.
An indication of the passage of fault current is given by a flashing LED for a
pre-set time period. At the same time the relay contacts operate giving an
electrical remote alarm.
On completion of the time period the unit will automatically self reset and is
then ready to detect subsequent faults. The F20 may also be manually reset,
remotely reset via a telecontrol DC reset signal or on restoration of AC
supplies.
Each of the EF elements is available for use with either a core balance CT or
three phase CTs. The CT arrangements are factory set.
A lithium battery provides power to the unit. The battery will provide up to 20
years life between changes.
A 12-24V dc supply can be connected as an alternative to the lithium battery.
