Description

GE Multilin T35 Transformer Protection System

The GE Multilin T35, also cataloged as the T35 Transformer Protection System, operates as a dedicated hardware component for transformer differential protection, backup protection, monitoring, and control within Universal Relay (UR) platforms.

Hardware Specifications

Parameter	Specification
Model	GE Multilin T35
Brand	GE Multilin
Origin	GE Multilin Universal Relay (UR) Series
Operating Temp	-40 deg C to +60 deg C
Protection Functions	87T transformer differential, 87N REF, 50/51 overcurrent, 49 thermal overload, 27/59 voltage, 81O/81U frequency, 24 overexcitation
Current Inputs	Up to 6 CT inputs, 1 A or 5 A nominal
Voltage Inputs	Up to 3 VT inputs, 100-240 V AC nominal
CT Withstand Capability	20 A continuous, 500 A for 1 second short-time
Power Supply Options	110-250 V DC / 110-240 V AC or 24-48 V DC
Ethernet Communication	10/100Base-T copper or 100Base-FX optical fiber
Serial Communication	RS485, RS232, RS422, G.703, C37.94
Communication Protocols	IEC 61850, DNP 3.0, Modbus TCP/IP, Modbus RTU, IEC 60870-5-103/104
Digital I/O	Configurable digital inputs, Form A/C relay outputs, Solid State Relay outputs
Event Recording	1024 time-tagged events
Oscillography	Up to 64 samples per cycle

GE Multilin UR Platform Communication and Control Features

The GE Multilin T35 integrates with the Universal Relay (UR) backplane architecture using modular I/O, communication, and power supply configurations. The relay supports deterministic substation communication networks through IEC 61850 Edition 1 and Edition 2, Ethernet interfaces, and direct relay-to-relay data exchange.

The T35 provides FlexLogic programmable control functions for custom protection schemes without external auxiliary relays. Firmware flash compatibility supports field configuration management through EnerVista UR engineering tools.

The communication architecture supports IEEE 1588 time synchronization, PRP network redundancy, and embedded Ethernet switching options. Network configuration can include copper, fiber optic, and serial communication interfaces depending on installed hardware modules.

Frequently Asked Questions

Q: Does the T35 support transformer inrush detection?
A: Yes. The relay applies second harmonic restraint for magnetizing inrush recognition and fifth harmonic restraint for overexcitation blocking.

Q: What type of communication interfaces are available on the T35?
A: The relay supports Ethernet, serial interfaces, and protocols including IEC 61850, DNP 3.0, Modbus TCP/IP, and Modbus RTU depending on the installed communication modules.

Q: Can the T35 exchange protection signals directly with other UR relays?
A: Yes. Direct I/O communication enables high-speed exchange of data between UR devices for applications such as direct transfer trip functions.

Field Installation Guidelines

Install the T35 in a suitable protection panel or relay rack with correct mechanical support and access clearance for wiring and maintenance.

Connect CT secondary circuits using dedicated twisted wiring paths with appropriate terminal security. Maintain separation between current transformer circuits, voltage transformer circuits, communication cables, and high-energy switching conductors.

Apply shield grounding practices according to the substation grounding design. Communication cable shields should be terminated according to the selected copper or fiber interface requirements.

Verify auxiliary power supply polarity and voltage range before energization. Confirm CT polarity, phase compensation settings, grounding configuration, and protection element parameters during commissioning.

Configure Ethernet network parameters, time synchronization sources, and IEC 61850 datasets after physical installation. Perform relay self-test verification and review event records before placing the protection system into service.

Specifications

• Brand: General Electric

Advantages

• High reliability in industrial environments
• Supports continuous operation
• Compatible with major PLC/DCS systems