Megger SR-98, Инструкция по эксплуатации

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SELECTION OF MASTER UNIT
Each Model SR-98 can be operated independently. However, when performing tests
that require more than one SR-98, such as testing current differential relays, it is
necessary to select one unit as a Master Unit. The Master Unit establishes the phase
reference for both Master and Slave units. This allows the output currents to be virtually
in-phase, when doing slope (differential characteristic) tests (requires the same rated
output tap is used for both units). Additionally, the Master Unit controls the initiation of
both AC CURRENT MAIN outputs.
Since all Model SR-98 test sets are identical, any unit can be used as the Master Unit.
Incorporated on the front panel of the SR-98 is an interface terminal port next to the
following symbol,
To interconnect two SR-98 units together requires the optional interface cable, part
number 51679. Simply plug the interface cable into the two interface terminals prior to
turning the units on. From the POWER UP Screen, press the MASTER SLAVE
SELECT button on both units. Then press the MODE SELECT button for the Slave Unit.
Note that both displays changed. The Slave Unit states that it is Slave and the external
unit is the Master, while the Master Unit states that it is Master and the external unit is
the Slave. Press the PREV SCREEN button to return to the POWER UP Screen.
Normally, the Master/Slave mode is used when test requirements call for two currents.
The two currents are normally used to provide restraint and operating currents when
testing current differential relays. Another application is when you want the currents to
sum as when testing harmonic restraint elements. To test current differential relays,
see TESTING CURRENT DIFFERENTIAL RELAYS for the step by step test procedure.