2.15
Date Code 20081022 Instruction Manual SEL-787 Relay
Installation
Rear-Panel Connections
Power Connections
The POWER terminals on the rear panel (A01 (+/H) and A02 (—/N)) must connect
to 110–240 Vac, 110–250 Vdc, or 24–48 Vdc (see Power Supply on page 1.8
for complete power input specifications). The POWER terminals are isolated
from chassis ground. Use 14 AWG (2.5 mm
2
) to 16 AWG (1.5 mm
2
) size wire
to connect to the POWER terminals.
For compliance with IEC 60947-1 and IEC 60947-3, place a suitable external
switch or circuit breaker in the power leads for the SEL-787; this device
should interrupt both the hot (+/H) and neutral (-/N) power leads. The
maximum current rating for the power disconnect circuit breaker or optional
overcurrent device (fuse) should be 20 A. Be sure to locate this device within
3.0 m (9.8 feet) of the relay.
Operational power is internally fused by a power supply fuse. See Field
Serviceability on page 2.26 for details. Be sure to use fuses that comply with
IEC 60127-2.
Grounding (Earthing)
Connections
You must connect the ground terminal labeled GND on the rear panel to a rack
frame or switchgear ground for proper safety and performance. Use 14 AWG
(2.5 mm
2
) wire less than 2 m (6.6 feet) in length for the ground connection.
Serial Ports
Because all ports (F, 2, 3, and 4) are independent, you can communicate to any
combination simultaneously. Although serial Port 4 on the optional
communications card consists of an EIA-485 (4A) and an EIA-232 (4C) port,
only one port is available at a time. Use the Port 4 communications interface
COMMINF setting to select between EIA-485 and EIA-232.
The serial port EIA-485 plug-in connector accepts wire size AWG 24 through
AWG 12. Strip the wires 8 mm (0.31 inches) and install with a small slotted-
tip screwdriver. All EIA-232 ports accept 9-pin D-subminiature male
connectors.
For connecting devices at distances over 100 feet, where metallic cable is not
appropriate, SEL offers fiber-optic transceivers or the fiber-optic port. The
SEL-2800 family of transceivers provides fiber-optic links between devices
for electrical isolation and long-distance signal transmission. Contact SEL for
further information on these products.
IRIG-B Time-Code Input
The SEL-787 accepts a demodulated IRIG-B time signal to synchronize the
internal clock with an external source. SEL-787 relays with an EIA-485 serial
port option for Port 3 have an external IRIG-B input at terminals B01 and B02.
SEL-787 relays with an EIA-232 serial port option for Port 3 have the IRIG-B
available in the EIA-232 port and can be connected to an SEL
communications processor. The available communications processors are the
SEL-2032, SEL-2030, SEL-2020, and the SEL-2100 Logic Processor.
Ethernet Port
The SEL-787 can be ordered with optional single/dual communications ports
of a 10/100BASE-T or 100BASE-FX Ethernet port. Connect to Port 1 of the
device using a standard RJ-45 connector for the copper port and an LC
connector for the fiber-optic port.
Contact with instrument terminals can
cause electrical shock that can result
in injury or death.
!
DANGER
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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