Description

GE L30 Line Current Differential System

The GE Multilin L30, also cataloged as the L30 Line Current Differential Relay, operates as a dedicated hardware component for phase-segregated current differential protection and high-speed fault clearance within GE UR (Universal Relay) protection platforms.

Hardware Specifications

Parameter	Specification
Model	L30
Brand	GE Multilin
Origin	GE UR (Universal Relay) Series
Operating Temp	-40 deg C to +60 deg C
Protection Function	Line current differential protection (87L)
Protection Elements	Distance protection (21/21N), overcurrent protection, voltage protection
CT Input	Configurable 1 A / 5 A CT secondary
VT Input	100-240 V AC VT secondary
Communication Interfaces	Fiber optic, G.703, C37.94, Ethernet
Network Protocols	IEC 61850 Ed. 1/2, DNP 3.0, Modbus RTU/TCP/IP, IEC 60870-5-104
Ethernet Support	100Base-FX, 100Base-TX, PRP/HSR
Power Supply Options	110-250 V DC / 110-240 V AC or 24-48 V DC
Enclosure Rating	IP40 front panel, IP20 rear chassis

Profinet / EtherNet-IP Deterministic Network and Firmware Compatibility

The GE Multilin L30 integrates high-speed relay processing with modular communication and control resources within the UR hardware architecture. The device supports deterministic Ethernet-based protection communication through IEC 61850 MMS and GOOSE messaging, with redundant Ethernet options for network topology requirements.

The relay firmware structure supports configuration management through standardized settings files and maintains compatibility with UR family engineering tools. Internal processing handles line differential calculations, synchrophasor measurement, disturbance recording, and protection logic execution within the relay processor environment.

Frequently Asked Questions

Q: Does the L30 support multi-terminal line differential protection configurations?
A: Yes. The L30 supports phase-segregated line differential protection for up to three terminals with communication channel supervision and direct transfer tripping functions.

Q: What CT and VT signal interfaces are supported by the hardware?
A: The relay supports configurable CT modules with 1 A or 5 A secondary inputs and VT inputs rated for 100-240 V AC secondary signals.

Q: What communication protocols are available for integration with protection networks?
A: The L30 supports IEC 61850 Edition 1 and Edition 2, GOOSE, MMS, DNP 3.0, Modbus RTU/TCP/IP, IEC 60870-5-104, and IEEE 1588 PTP synchronization.

Field Installation Guidelines

Install the L30 relay in a compatible UR rack environment with correct mechanical mounting and rear terminal connection alignment. CT and VT wiring should follow protection engineering practices, including separate routing from high-voltage conductors and appropriate shielding for low-level measurement circuits.

Fiber optic communication connections should maintain correct optical interface matching between relay terminals. Ethernet and serial communication wiring should be installed according to network grounding and shielding requirements.

Verify control power polarity and voltage range before energizing the relay. Digital input wiring should maintain electrical isolation requirements, and output contact circuits should be connected according to the assigned protection scheme.

Specifications

• Brand: General Electric

Advantages

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