ABB REL 301, Instruction Manual

Page: 77 / 132

I.L. 40-386.3
(10/94) 3-9
NOTE: The setting of
∆
I,
∆
V, for OSC is not recommended since data will
be collected for normal operations.
3.3.2 Fault Data (Flt. Data) Capture Setting
Is for selecting one of the 3 ways (TRIP/Z2TR/Z2Z3) to initiate the fault data taken,
where:
TRIP – to store fault data only if trip action occurs.
Z2TR – to store fault data if Zone2 units pick up or any trip action occurs.
Z2Z3 – to store fault data if Zone2 or Zone3 units pick up or any trip action occurs.
3.3.3 Current Transformer Ratio Setting (CT Ratio)
The CT Ratio is used for the load current monitoring, if it is selected to be displayed
in primary amperes. It has no effect on the protective relaying system.
For this example, set CT Ratio = 240.
3.3.4 Voltage Transformer Ratio Setting (VT Ratio)
The VT Ratio is used for the system voltage monitoring, if it is selected to be displayed
in primary volts. It has no effect on the protective relaying system.
For example, set VT Ratio = 600.
3.3.5 Frequency Setting (Freq.)
Should be selected to match the power system operating frequency.
For example, select Freq. = 60 if the power system operating frequency is 60 Hertz.
3.3.6 Current Transformer Type Setting (CT Type)
Provides the flexibility for 5 amp or 1 amp rated current transformer selection.
For example, select and set CT Type = 5 if a 5 amp current transformer is used.
The setting of CT Type affects all the distance unit and overcurrent unit setting rang-
es. The ranges will be automatically changed as listed in Table 3-1 :
3.3.7 Read Primary Setting (Read Out)
The Read Out should be set to Primary Units if all the monitoring ac voltages and currents are
selected to be displayed in primary KV and KA values, respectively.
3.3.8 Ohms Per Unit Distance (X / Dist)
The line reactance setting X / Dist is the multiplier for fault distance display. It has a range of
0.3 to 1.5 ohms (primary) in 0.001 steps. In this example, the line reactance is 0.8 ohms/mile;
set X / Dist = 0.8.