Setting Guidelines - ABB REG670 Applications Manual

1MRK 502 071-UEN -
8.8.3
8.8.3.1
Generator protection REG670 2.2 IEC and Injection equipment REX060, REX061, REX062
Application manual
capacitance and conductance to ground between standstill and fully loaded machine
will also limit the possible setting level for the alarm stage. As a consequence 10 kΩ
sensitivity can be typically reached without problem. Depending on particular
installation alarm sensitivity of up to 50 kΩ may be reached at steady state operating
condition of the machine.
Note that it is possible to connect two REG670 in parallel to the REX060 injection unit
in order to obtain redundant measurement in two separate IEDs. However, at
commissioning both REG670 IEDs must be connected during calibration procedure.

Setting guidelines

Setting injection unit REX060
The 100% stator earth fault protection module in the REX060 generate a square wave
signal for injection into the stator windings of the generator via the neutral point. The
injected voltage and current are connected to the measurement parts of REX060. The
signals are amplified giving voltage signals for both the injected voltage and current,
adapted to analogue inputs of IED.
Frequency, current and voltage gain are settable and stored in non-volatile memory.
If value is outside range, then the limited value will be stored. Last stored settings are
shown in display.
Table 32: Necessary settings for REX060
Setting
System frequency
Injected frequency
UmaxEF [V]
Injection frequency can be set as integer in range 50 to 250 Hz. When selected, only
one digit can be adjusted at the time by the Up or Down buttons. Store the new value
by Enter button, or alternatively recover to the last stored value by Clear button.
Gain setting can be set in four discreet steps for SIM in the main menu. These
selectable steps, in turn result in pre defined voltage and current gain factors. The gain
can be adjusted by the Up or Down buttons when selected. Store the new gain by the
Enter button, or alternatively recover to the last stored gain by the Clear button.
Stator gain should be set to the VT/DT rating. That voltage is dependent on the VT/DT
ratio and the highest possible voltage at neutral point. Gain factor (UmaxEF) shall be
selected to correspond to this voltage which shall be at least the same as VT/DT value
in table below.
Impedance protection
Range
50/60 Hz
50 to 250 Hz
Four steps for the 100% stator earth fault
protection
Section 8
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