Product Description; Introduction; Overview - GE T35 Instruction Manual

2 PRODUCT DESCRIPTION

2 PRODUCT DESCRIPTION 2.1INTRODUCTION
The T35 Transformer Management Relay is a microprocessor-based relay intended for protecting small, medium, and large
three-phase power transformers involved in complicated power system configurations. The relay is available with two to six
banks of three-phase inputs: either CTs or CTs and VTs. Typical T35 applications include:
• Transformers with windings connected between two or more breakers,
• Transformers with windings without associated breakers, where the only available ones are those on buses, lines, or
feeders.
The percent and instantaneous differential elements are the primary protection elements. The backup protection elements,
such as instantaneous overcurrent, can be expressed in fully configurable FlexElements™. The relay can also be config-
ured to protect transformers with any phase shift between the windings and handle up to 32 times the ratio mismatch (see
the Phase and Magnitude Compensation descriptions).
Voltage, current, and power metering is built into the relay as a standard feature. Current parameters are available as total
waveform RMS magnitude, or as fundamental frequency only RMS magnitude and angle (phasor).
The internal clock used for time-tagging can be synchronized with an IRIG-B signal or via the SNTP protocol over the
Ethernet port. This precise time stamping allows the sequence of events to be determined throughout the system. Events
can also be programmed (via FlexLogic™ equations) to trigger oscillography data capture which may be set to record the
measured parameters before and after the event for viewing on a personal computer (PC). These tools significantly reduce
troubleshooting time and simplify report generation in the event of a system fault.
A faceplate RS232 port may be used to connect to a PC for the programming of settings and the monitoring of actual val-
ues. A variety of communications modules are available. Two rear RS485 ports allow independent access by operating and
engineering staff. All serial ports use the Modbus
with baud rates up to 115.2 kbps. The RS232 port has a fixed baud rate of 19.2 kbps. Optional communications modules
include a 10BaseF Ethernet interface which can be used to provide fast, reliable communications in noisy environments.
Another option provides two 10BaseF fiber optic ports for redundancy. The Ethernet port supports IEC 61850, Modbus
TCP, and TFTP protocols, and allows access to the relay via any standard web browser (T35 web pages). The IEC 60870-
5-104 protocol is supported on the Ethernet port. DNP 3.0 and IEC 60870-5-104 cannot be enabled at the same time.
The T35 IEDs use flash memory technology which allows field upgrading as new features are added. The following Single
Line Diagram illustrates the relay functionality using ANSI (American National Standards Institute) device numbers.
Table 2–1: DEVICE NUMBERS AND FUNCTIONS
DEVICE FUNCTION
NUMBER
50/87 Instantaneous Differential Overcurrent
51G Ground Time Overcurrent
51P Phase Time Overcurrent
87T Transformer Differential
GE Multilin
®
RTU protocol. The RS485 ports may be connected to system computers
T35 Transformer Management Relay

2.1 INTRODUCTION

2.1.1 OVERVIEW

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