Advertisement
I.L. 40-201.9
The apparent impedances seen by the relay in each of the above positions and the expected operation of the
inner (21 BI) and outer (21 BO) blinders are the following:
The following tests make sure that the transmitter and receiver are connected in the unit.
NOTE:
Test #1 indicates the sequence of positions in the RX diagram to be applied and the time in cycles to hold the
position and the action of the relay.
The fault impedance measured should be 10.6 ∠105 ohms.
I-10
POS
Z app
13.8 ∠5
1
4.47 ∠25
2
3.33 ∠65
3
5.00 ∠100
4
10.6 ∠105
5
Make sure that the loopback connections described in 7.1 and 7.2 are made.
Also, the metered value CHRX displayed should be ARM.
TEST #1
Trip OST on the Way Out
Pos
Time
A
1
60
2
5
3
20
4
5
5
60
Power Automation and Protection Division
21 BI
41 BO
No
No
No
Yes
Yes
Yes
No
Yes
No
No
Trip Action
50-67 ms after 2
REL 352 Version 1.00
Advertisement
