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However, the user might program the
criteria for operation to suit his local
requirement by manipulating a bank of
micro-switches inside the indicator.
Note: Voltage or current as start and
stop criteria are user programmable.
2.1. Sensors
The magnetic field generated by the line
current induces a signal in the indicator
pickup coil. The induced signal is applied
to a di/dt sensor in order to discriminate
between fault current and load current.
The di/dt sensor detects instant current in-
creases as is the case when faults occur.
The trip level of the di/dt can be set to 6,
12, 25, 60, or 120 A by means of a switch
bank inside the unit.
A normal variation of the load current will
not activate LINETROLL 110E.
Figure 1: Magnetic field sensor principle.
Figure 2: Electric field sensor principle
LINETROLL 110E /110Eµr User Guide February 2010
The line voltage is detected by means of an
aerial placed inside the indicator.
2.2. Activation criteria
LINETROLL 110E can be easily set to
operate in the wanted mode by altering a
number of switches inside the unit.
In order to avoid activating the indicator
due to the magnetising inrush current of the
line, it's di/dt sensor is blocked for 5 sec.
upon re-energising of the line. While the
blocking time elapses, the line current
stabilises and does not cause triggering of
the di/dt sensor.
A fault duration exceeding 60ms is
required to activate the indicator.
In addition to its di/dt sensor,
LINETROLL 110E incorporates a
common threshold sensor with threshold
levels of 250, 500A, 750A or 1000A. The
threshold criterion, if enabled, activates the
indicator if the fault current exceeds the
selected level. (The inrush blocking is still
active in this mode)
A rapid line current increase followed by a
de-energising of the line within 5 sec. will
activate the indicator.
It can also be set to indicate upon a rapid
current increase without looking for a de-
energised line.
2.3. Indication
The main indication; 4 red/amber LED's
indicates permanent faults. The secondary
indication is a single green LED.
Transient fault: Only the green LED
flashes for 24h.
Permanent fault: Both green and
red *) until reset (timer-, auto- or
manual-reset).
*) Note: to verify a permanent fault, the red
Indication is delayed 70 sec. See more
detailed info Ch 10 Flashing sequence.
Page 4 of 16
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