Sel 751A - Voltage Card Option; Table 2.2 Communication Card Interfaces and Connectors; Table 2.3 3 AVI Voltage Card Terminal Designation

2.5
Date Code 20100129 Instruction Manual SEL-751A Relay
Installation
I/O Configuration
Communications Card
Either the DeviceNet (see Appendix G: DeviceNet Communications) or the
EIA-232/ EIA-485 communications card is supported in Slot C. The EIA-232/
EIA-485 card provides one serial port with one of the following two serial
port interfaces:
➤ Port 4A, an isolated EIA-485 serial port interface
➤ Port 4C, nonisolated EIA-232 serial port interface, supporting
the +5 Vdc interface
Select either EIA-232 or EIA-485 functionality using the Port 4 Setting
COMM Interface. Table 2.2 shows the port number, interface, and type of
connector for the two protocols.
The communications card supports all of the following protocols:
➤ Modbus RTU Slave
➤ SEL ASCII and Compressed ASCII
➤ SEL Fast Meter
➤ SEL Fast Operate
➤ SEL Fast SER
➤ SEL Fast Message Unsolicited Write
➤ SEL Settings File Transfer
➤ SEL MIRRORED BITS (MBA, MBB, MB8A, MB8B, MBTB,
MBTA)
➤ Event Messenger
➤ DNP3 Slave Level 2
➤ C37.118 (Synchrophasor Data)
Voltage Card Option
(3 AVI)
MOT…x71x… Supported in Slot E only, order this card when you have
either single or three-phase (wye or delta) PTs. With a voltage card installed,
the SEL-751A tracks the frequency (using positive-sequence voltage) and
samples at 16 times a cycle—see Processing Specifications on page 1.23 for
more information.
Table 2.2 Communication Card Interfaces and Connectors
Port Interface Connectors
4A EIA-485 5-pin Euro
4C EIA-232 D-sub
Table 2.3 3 AVI Voltage Card Terminal Designation
Te r m in a l N u m b e r Description
01 VA, Phase A voltage input
02 VB, Phase B voltage input
03 VC, Phase C voltage input
04 N, Common connection for VA, VB, VC
05 N, Common connection for VA, VB,VC
06 N, Common connection for VA, VB,VC
NOTE: The relay tracks the
frequency if 3V1 is greater than 0.75 V.