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Binary input for control function
This input allows remote opening of the circuit-
breaker.
The input must be made with a screened two-pole
cable. Screening must be earthed on the metal
box of the PR512 (please refer to the connection
diagram enclosed with the circuit-breaker).
By connecting an unsupplied external contact (e.g.
the contact of a Buchholz relay) to the special
input connector, it is possible to control circuit-
breaker opening remotely through the PR521
when the primary current exceeds the value of 0.2
x In on at least one phase fitted with a current
sensor.
Should tripping for phase currents under 0.2 x In
have to be guaranteed, the auxiliary power supply
is required.
The maximum length of the connection is 30m.
The connection must be made with a screened
two-pole cable.
Front view of the TT2 Test Unit
– Put Dip Switch 1 in position A to enable TT2 for
operation. This also enables the test unit power
supply with the display therefore lighting up.
In this case, it is also possible to carry out hardware
resetting of the protection and resetting of the K51/
YO3 signalling relays.
– Put Dip Switches 1 and 2 in position A and press
the TEST pushbutton to release the YO3 opening
solenoid with consequent circuit-breaker opening.
– Put Dip Switches 1 and 3 in position A and press
the TEST pushbutton to check functions I> and I>>
TEST function
By using the TT2 accessory (Test Unit supplied
on request), the overall functionality TEST of the
relay release (electronic part and YO3 opening
solenoid) can be carried out.
By means of the 9 PIN connector, the TT2 Test
unit allows the TEST to be carried out on func-
tions 50-51 in the configuration with definite time
curve (DT). The above-mentioned TEST can be
carried out with the YO3 opening solenoid
activated (TRIP) or de-activated (TEST).
Rear view of the TT2 Test Unit
Use of the TT2 unit
(only for the fixed time curves) and start selected
function timing with subsequent release of the YO3
opening solenoid and consequent circuit-breaker
opening.
– Put Dip Switches 1, 3 and 4 in position A if the YO3
opening solenoid opening command is to be
disabled during checking of function I> and I>>.
– To carry out self-diagnosis of the battery charge
and correct operation of the TT2, put Dip Switch 1
in position A, press the CHECK pushbutton and
verify that the LED lights up. If the LED is off, the
battery must be replaced.
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