Alstom MiCOM P846, Technical Manual

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P846/EN CM/D Commissioning
(CM) 10-10
MiCOM P846
Carefully examine the relay to see that no physical damage has occurred since installation.
Ensure that the case earthing connections, bottom left-hand corner at the rear of the relay
case, are used to connect the relay to a local earth bar using an adequate conductor.
5.1.2 Current transformer shorting contacts (optional check)
If required, the current transformer shorting contacts can be checked to ensure that they
close when the heavy duty terminal block (block reference D and E in Figure 1) is
disconnected from the current input PCB.
Rear port with IRIG-B time synchronizing input which are available with the relay.
18
16
A B
1
C
1
18 18 18 18
16
17
18
18
18 17
19 2 3 1
18 18
3 2
D
1 19
E F
1
G
1
H
1
J
1
K
1
L
1
M
Current and Voltage
Input Terminal
Power Supply
Connection
Rear Comms
Port (EIA485)
Digital Input Connection
Digital Input Connection
IRIG-B and 2nd Rear
Comms Board
Digital Output Connection
Figure 1: Rear terminal blocks on size 80TE case (B variant)
The heavy duty terminal block is fastened to the rear panel using four crosshead screws.
These are located top and bottom between the first and second, and third and fourth,
columns of terminals (see Figure 2).
CM
Note: The use of a magnetic bladed screwdriver is recommended to
minimize the risk of the screws being left in the terminal block or lost.
Pull the terminal block away from the rear of the case and check with a continuity tester that
all the shorting switches being used are closed. Table 1 shows the terminals between which
shorting contacts are fitted.
Current Input Shorting Contact Between Terminals
1A CT’s 5A CT’s
IA D3 – D2 D1 – D2
IB D6 – D5 D4 – D5
IC D9 - D8 D7 – D8
IA(2) F18 – F17 F16 – F17
IB(2) F15 – F14 F13 – F14
IC(2) F12 – F11 F10 – F11
Table 1: Current transformer shorting contact locations