IL04915001E
Effective 7/09
2
For the CT supervision feature to work a 500:1
ratio Series A2 C311CT must be installed, as
specified in section 5.
1.3 LED indicators
The unit has two LEDs. A green LED shows
correct operation by slowly flashing (1 s on / 1 s
off). When the unit is in a tripped condition, a red
LED shows short 0.25 s flashes as a code
indicating the cause of the trip:
•
One 0.25 s flash every few seconds means
Ground fault current exceeded the set G/F
limit, but did not reach S/C levels. This trip is
labeled ‘G/F’.
•
Two consecutive 0.25 s flashes every few
seconds means Ground fault current
exceeded the S/C level. This trip is labeled
‘S/C’.
In case Type 2 Co-ordination is used, this
code also means that the upstream device
tripped correctly; after the current dropped to
zero as a result of the upstream trip, the
D64RPB30 activated its trip relay to isolate
the faulty circuitry.
•
Three consecutive 0.25 s flashes every few
seconds can only occur when Type 2 Co-
ordination is used. It means that Ground fault
current exceeded the S/C level, but the
upstream device failed to trip. The
D64RPB30 then tripped as a last resort. This
trip is labeled ‘Backup’. The contactor should
be replaced since its contacts may have
been damaged due to the S/C current.
•
Four consecutive 0.25 s flashes every few
seconds means that the connection to the
external CT is either open or shorted. Note
that the trip is latched until reset; therefore
intermittent failures will be captured,
overcoming the impression that the unit
tripped without cause.
•
Continuous 0.25 s flashes indicate an extra
‘trip failed’ alarm state on top of one of the
possible trips described above.
Following the operation of the trip relay,
measured ground fault current remained at a
high level. When the local or remote reset
button is first pressed, the trip is not reset,
but the ‘trip failed’ alarm state is. As a result
the red LED will now show the original cause
of the trip.
1.4 Reset / Test pushbutton
The built-in momentary pushbutton is used to
verify the condition of the D64RPB30 if control
voltage has been removed from the relay (see
section 1.5)
and to reset the internal relay and/or
the red LED (depending on the exact Operating
Mode, see section 1.6).
The reset will only be granted if the cause of the
trip is cleared. Otherwise the relay will remain
activated without resetting. If the cause of the
trip is cleared but another fault exists, then
pressing the reset button will reset the trip
indication on the red LED. This permits the new
trip code to be displayed. However, the relay will
remain activated without resetting.
Double-clicking the local button invokes a test
which switches an AC voltage onto the
processor’s CT sensor input. The voltage is
scaled to simulate a Ground fault current of 1.5
times the G/F trip level setpoint. The unit will trip
on G/F after the set delay (plus 0.4 s) and then
switch off the AC voltage. Press the reset button
again to reset the device. No external power
supply is required.
1.5 Memory after loss of control voltage
When control voltage is removed from the
D64RPB30, the condition of the relay will be
memorized (for at least one week). Pressing the
Reset pushbutton before restoring control
voltage will light either the green LED or the red
LED, green indicating no trip was registered and
red indicating the opposite. The green LED will
light continuously, whereas the red LED will give
a sequence of short flashes as described in
section 1.3 indicating the cause of trip. Please
note that if the D64RPB30 is operated in one of
the Failsafe modes (see section 1.6), and there
was no trip when control voltage disappeared,
the system will still activate its relay at the very
moment of losing voltage. If this is what
happened, the red LED will show five
consecutive short flashes, meaning ‘relay was
merely activated because control voltage was
lost while operating in Failsafe mode’.
