2.13
Date Code 20170601 Instruction Manual SEL-387-0, -5, -6 Relay
Installation
Circuit Board Configuration
The dc connection diagram, Figure 2.9, illustrates tripping control of the three
power circuit breakers. The diagram includes three 52a input contacts to
define breaker status (open or closed) and a separate 86 lockout relay for
group tripping on a differential operation. Individual breaker trips occur for
overcurrent operation.
The diagram also shows ALARM and annunciation functions. The ALARM
contact comes factory wired as a form-B contact, so that it closes under
conditions of complete relay power failure. If breaker closing control were
desired, we would use the Trip Annunciator contact (OUT105) as one of the
three separate output contacts for connection to the breaker closing coils. That
is, for this case the breaker trip and close functions together would require all
seven standard output contacts.
Figure 2.9 Example DC Connections (Basic Version)
Circuit Board Configuration
In this section we describe the following:
➤ How to remove the relay circuit boards so you can change
circuit board jumpers or replace the clock battery
➤ How to replace the circuit boards in the relay
Accessing the Relay
Circuit Boards
Step 1. De-energize the relay by removing the connections to rear-
panel terminals + (Z25) and – (Z26).
Accomplish this easily on Connectorized relays by removing
the connector at rear-panel terminals + (Z25) and – (Z26).
Step 2. Remove any cables connected to serial ports on the front and
rear panels.
Step 3. Loosen the six front-panel screws (they remain attached to the
front panel) and remove the relay front panel.
Step 4. Each circuit board corresponds to a row of rear-panel terminal
blocks or connectors and is affixed to a draw-out tray. Identify
which draw-out tray needs to be removed. An SEL-387
SEL-387
(partial)
Power
Supply
A17
A18
IN101 IN102 IN103
TRIP
ANN
FAIL
ANN
OUT104 OUT105 ALARM
A19
A20
A21
A22
A07
A08
A09
A10
A15
A16
Z25
Z26 Z27
GND
A02 A04 A06
A01 A03 A05
+DC
–DC
+DC
–DC
+DC
–DC
+DC
–DC
Remaining: 3 Inputs (IN104–IN106)
2 Outputs (OUT 106, OUT107)
52-1
a
52-1
a
52-2
a
52-3
a
52-1
TC
52-2
TC
52-3
TC
52-2
a
52-3
a
86T
b
86T
a
86T
a
86T
a
86T
OP
The relay contains devices sensitive
to Electrostatic Discharge (ESD).
When working on the relay with the
front panel removed, work surfaces
and personnel must be properly
grounded or equipment damage may
result.
!
CAUTION
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