58
Harmonic Restraint Test:
The
Harmonic Restraint Test
requires two SR-98’s operating in Master/ Slave mode,
see
SELECTION OF MASTER UNIT
. Select one unit to be Slave unit. The Master unit
INIT button controls both the Master and Slave AC CURRENT MAIN outputs. It also
establishes the in-phase relationship between the two currents. When choosing output
taps, select the same tap for both units. For example, use the 10 Amp output tap on
both units. Note: Failure to use the same output taps will result in phase shift error
between the two currents. One unit (in this procedure the Slave Unit) will provide the
harmonic current, 2 nd, 3 rd or 5 th. The second unit, the Master Unit, will provide the
fundamental (sometimes referred to as the “by-pass” current).
From the
TEST MENU
Screen on both units, select
CURRENT RELAY
. The following
test screen should be displayed.
Connect Relay Trip contacts to
STOP/MONITOR
terminals.
Note: If relay is solid state, microprocessor-based, or has a DC auxiliary relay that
requires a DC voltage prior to applying test currents, connect the appropriate relay
terminals to the Master Unit
DC AUX
terminals. With the arrow key, highlight the
DC
VOLTS
and press the
DC
Button. Increase the DC voltage output by rotating the Master
Unit Control Knob until proper voltage is applied.
Connect the Master Unit
AC CURRENT MAIN
,
10 A
output terminal and common
return to the relay terminals so that the test current will energize the Operating Coil
(Element) and one Restraint Coil (Element). Connect the Slave Unit
AC CURRENT
MAIN
,
10 A
output terminal and common return in parallel with the Master Unit test
connections, so that the test currents will add across the same two Coils (Elements).
Note: Observe polarity. Connect the two Common returns to the same relay terminal.
1.
AC AMPERES
should be highlighted on both Master and Slave units.
2.
To set the desired harmonic on the Slave Unit, press the
TIMER SETUP
button.
The following screen should be displayed.
Содержание SR-98
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