ABB Relion 650 Series Applications Manual page 71

1MRK 505 287-UUS B
6.1.3.1 Configuration
The configuration is done in the Application Configuration tool. For example, signals from external
check criteria shall be connected to the inputs as required for the application.
BLOCK input is used to block the function for example, from external check criteria.
BLKTR input is used to block the function tripping for example, from external check criteria. The
alarm level will be operative.
6.1.3.2 Settings of protection function
Operation : The operation of the high impedance differential function can be switched Enabled or
Disabled .
AlarmPickup : Set the alarm level. The sensitivity can roughly be calculated as a divider from the
calculated sensitivity of the differential level. A typical setting is 10% of
as scheme supervision stage.
tAlarm : Set the time for the alarm. A typical setting is 2-3 seconds.
TripPickup : Set the trip level according to the calculations in the examples for each application
example. The level is selected with margin to the calculated required voltage to achieve stability.
Values can be 20-200 V dependent on the application.
R series : Set the value of the stabilizing series resistor. Calculate the value according to the
examples for each application. Adjust the resistor as close as possible to the calculated example.
Measure the value achieved and set this value here.
6.1.3.3 Busbar protection
The 1Ph High impedance differential protection HZPDIF (87) function can be used to protect the
busbars with relatively few feeders.
Busbar protection REB650
Application manual
The value shall always be high impedance. This means for example, for 1A circuits
say bigger than 400 ohms (400 VA) and for 5 A circuits say bigger than 100 ohms
(2500 VA). This ensures that the current will circulate and not go through the
differential circuit at through faults.
The settings of U>Alarm, U>Trip and SeriesResistor must be chosen such that:
• U>Alarm/SeriesResistor is >2% of IRated of the used current input
• U>Trip/SeriesResistor is >4% of IRated of the used current input
Normally the settings shall also be such that U>Alarm/SeriesResistor and U>Trip/
SeriesResistor both gives a value <4*IRated of the used current input. If not it must
be considered the limitation in how long time the actual current is allowed to
persist not to overload the current input.
© Copyright 2013 ABB. All rights reserved
Section 6
Differential protection
M13076-5 v3
M13076-10 v5.1.1
TripPickup. It can be used
M16850-80 v8
65