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Idiomas disponibles
Setting the Counter
The time counter has three modes of operation:— 'Normal', 'Runback' and 'Manual'. The purpose of each of these
modes is as follows:
Normal —
for measurement of the time from the commencement of current injection to the tripping (i.e. either
opening or closing) of the relay contacts.
In this mode the counter is triggered as soon as the 'Set/Test' switch is moved to the 'Test' position, assuming the
output has previously been set.
Upon tripping of the contacts in the device under test (or the current flow falling below the minimum threshold in the
output common terminal), the count will cease and the output will be turned off. The counter display will show the
recorded time.
Runback — for measurement of runback times (I.D.M.T. relays) i.e. the time the relay disc takes to regain its rest
position after it has tripped.
In this mode, the counter will be triggered upon the tripping of the contacts of the device under test rather than when
the 'Test' position is selected, (or the current flowing in the output common terminal falling below the minimum
threshold). The counter will then be stopped by depressing either the 'Manual' push-button on the control panel or
the remote 'Manual' push-button. The operator has to watch the device under test and press the push-button when
the disc stops rotating. The reading of the counter display indicates the runback time.
Manual —
for manual operation of the time counter.
In this mode of operation, either the 'Manual' push-button on the control panel or the remote 'Manual' push-button
is depressed both to start and stop the counter. The displayed reading is the recorded time.
Voltage Output d.c.
Proceed as opposite, except that the range switch should be set to indicate 240 V d.c. output, and the 240 V d.c.
terminals should be used.
Independent a.c. Voltage Output
1.
Proceed with the Preliminary Procedure until step (5), except that the 120 V a.c. terminals are now connected to
the device under test.
2.
Select the 120 V a.c. position on the range switch.
3.
Now turn the auxiliary output control clockwise until the desired output is displayed on the meter.
4.
If the counter is to be used with this output, then it should be operated in the 'Manual' mode.
Note:— Since it is envisaged that this output will normally be used as an auxiliary voltage source when testing
Directional relays, the counter has not been designed to operate with it automatically.
5.
Upon completion of the test, return the auxiliary output control fully anti-clockwise before disconnecting the
leads.
Use of Optional Filter Unit
1.
If the SF30 Filter Unit is being used, it should be connected at the Preliminary Procedure stage.
2.
The Unit is connected in series with either of the output leads such that the common terminal on the SF30 is
connected to the SCITS100, and the current terminal on the SF30 is connected to the device under test.
3.
The current terminal used on the SF30 should be chosen according to the maximum current to be injected. (See
table below.)
Current to be injected
0 — 1 A
1 — 2 A
2 — 5 A
5 — 10 A
10 — 30 A
> 30 A
Terminal to be used
1 A
2 A
5 A
10 A
30 A
The Filter Unit is not required with currents over 30 A
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