Megger SR-98, Инструкция по эксплуатации

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33
INSTANTANEOUS ELEMENT OF OVERCURRENT RELAYS
From the
TEST MENU
Screen, select
CURRENT RELAY
. The following test screen
should be displayed.
Connect Relay Trip contacts to
STOP/MONITOR
gate.
Connect the appropriate
AC CURRENT MAIN
output tap to the Current Coil (see
SELECTION OF OUTPUT TERMINALS
,
CURRENT MAIN
for guide to proper
selection).
Connect
DC AUX
output to relay (for solid state).
Connect
AC AUX
output to relay if AC controlled.
Note: If relay is solid state, or microprocessor-based, and requires a DC logic voltage
prior to applying test currents, connect the relay dc power terminals to the
DC AUX
terminals. With the arrow key, highlight the
DC VOLTS
and press the
DC
Button.
Increase the DC voltage output by rotating the Control Knob until proper logic voltage is
applied. If the relay is AC voltage controlled/restrained, see
VOLTAGE RELAY Test
for
typical tests on the AC voltage control/restraint element.
Instantaneous Pickup Test:
1.
Using arrow key highlight
AC AMPERES.
2. With
MODE
set to
MOM.
(MOMENTARY), press the
INIT
button. The output
current should turn on for a short pulse duration.
3.
Rotate Control Knob clockwise slightly, and press the
INIT
Button. Observe
current reading retained by ammeter. Continue this procedure until the
instantaneous element picks up.
4.
Read and record the Pick-up current. If a timing test is desired continue to the
next step, otherwise return the current to zero.