UR8LH 8-Channel Relay Output Module (Industrial-Grade Protection Control)

The UR8LH Relay Output Module represents a critical component in modern protection relay architectures, delivering eight independent Form-A (SPST-NO) relay contacts engineered for demanding industrial control applications. Designed as an integral expansion module for GE Multilin Universal Relay platforms, this unit provides the essential interface between digital protection logic and physical switchgear control circuits across power distribution, motor protection, and process automation installations.

Industrial facilities face increasing demands for reliable, high-speed control interfaces that can withstand harsh electrical environments while maintaining precise operation. The UR8LH addresses these challenges through robust contact design, comprehensive electrical isolation, and proven compatibility with the complete UR series ecosystem. Whether managing circuit breaker trip commands, coordinating load shedding sequences, or controlling auxiliary equipment, this module delivers the performance and reliability that critical infrastructure demands.

With sub-10-millisecond response times, 2500V AC isolation, and a wide operating voltage range, the UR8LH enables system integrators to build flexible, scalable protection and control solutions. Its hot-swappable architecture minimizes maintenance downtime, while extensive temperature ratings ensure continuous operation in the most challenging industrial environments.

Core Capabilities & Technical Advantages

→ Eight Independent Form-A Relay Outputs
Each channel provides a dedicated SPST-NO (normally-open) contact rated for 7A at 30VDC or 250VAC, enabling direct control of circuit breakers, contactors, annunciators, and auxiliary devices without intermediate interface relays.

→ High-Speed Contact Operation
Response times under 10 milliseconds ensure that protection commands translate to physical actions with minimal delay, critical for fault clearing, emergency shutdowns, and coordinated switching sequences in time-sensitive applications.

→ Comprehensive Electrical Isolation
2500V AC isolation between relay coils and contacts protects sensitive microprocessor-based protection systems from high-voltage transients, ground potential differences, and electromagnetic interference common in industrial power environments.

→ Universal Voltage Compatibility
Operates across 24-250VDC/VAC control voltage ranges, accommodating diverse installation requirements from low-voltage PLC systems to traditional 125VDC station battery supplies without external voltage conversion.

✓ Extended Environmental Ratings
-40°C to +85°C operating temperature range supports installations in outdoor switchyards, unheated equipment rooms, and thermally challenging industrial processes where standard electronics would fail.

✓ Hot-Swap Maintenance Capability
When deployed in compatible UR chassis configurations with redundant power architectures, modules can be replaced during live operation, eliminating costly process interruptions for routine maintenance or emergency repairs.

Industrial Application Scenarios

Substation Automation & Feeder Protection
In electrical distribution substations, the UR8LH integrates with digital feeder protection relays to execute circuit breaker control, recloser sequencing, and automatic transfer switching. The module's eight outputs typically manage breaker trip/close coils, lockout relay interfaces, SCADA remote indication, and alarm annunciation circuits. High isolation voltage protects relay logic from station ground potential rise during fault conditions.

Motor Control Center Integration
For critical motor protection applications, the UR8LH provides the control interface between microprocessor-based motor protection relays and motor starter contactors. Typical implementations use relay outputs for starter enable/disable commands, thermal overload bypass during starting, cooling system activation, and multi-level alarm signaling to plant control systems.

Transformer Protection & Control
Transformer protection schemes leverage the UR8LH for coordinated control of cooling equipment, tap changer operations, neutral grounding switches, and Buchholz relay interfaces. The module's fast response enables rapid de-energization sequences when internal faults are detected, minimizing equipment damage and improving personnel safety.

Generator Protection Systems
In power generation facilities, the UR8LH manages generator breaker control, excitation system interfaces, synchronization permissives, and emergency shutdown sequences. The wide voltage range accommodates both 125VDC station battery systems and 48VDC telecommunications power supplies common in distributed generation installations.

Process Industry Safety Systems
Chemical, petrochemical, and manufacturing facilities deploy the UR8LH in safety instrumented systems (SIS) where electrical protection relays coordinate with process safety logic. Applications include emergency pump shutdown, valve isolation commands, ventilation system activation, and multi-stage alarm escalation to distributed control systems.

Technical Parameters & Selection Criteria

Selection Guidelines:

Choose the UR8LH when your application requires normally-open contacts for simple on/off control functions such as circuit breaker trip commands, contactor enable signals, or alarm annunciation. The 7A contact rating accommodates most industrial control coils and pilot devices directly.

For applications requiring both normally-open and normally-closed contacts (such as interlocking circuits or fail-safe alarm systems), consider the UR8RH module which provides Form-C (SPDT) contacts. When output requirements exceed eight channels, multiple UR8LH modules can be installed in the same chassis, with the UR series supporting up to six I/O expansion modules depending on chassis configuration.

Verify that control circuit voltage falls within the 24-250VDC/VAC range. For specialized applications requiring higher contact ratings or alternative voltage ranges, consult the complete GE Multilin I/O module portfolio for application-specific solutions.

Advanced Integration Features

Modular System Architecture
The UR8LH integrates seamlessly into the Universal Relay modular platform, which supports flexible combinations of CPU modules, analog input modules, digital I/O modules, and communication interfaces. This architecture enables system designers to configure protection and control solutions precisely matched to application requirements without over-specifying hardware.

IEC 61850 GOOSE Mapping
When deployed with UR series relays equipped with IEC 61850 communication modules, relay outputs can be mapped to Generic Object-Oriented Substation Event (GOOSE) messages, enabling high-speed peer-to-peer communication between protection devices without routing through central SCADA systems.

Programmable Logic Integration
UR series CPU modules provide extensive programmable logic capabilities, allowing relay outputs to be controlled by complex Boolean equations, timers, counters, and analog comparators. This flexibility supports sophisticated control sequences such as load shedding prioritization, automatic restoration schemes, and coordinated switching operations.

Self-Monitoring & Diagnostics
The UR platform continuously monitors relay coil circuits and contact status, providing detailed diagnostic information through front-panel displays, communication protocols, and alarm contacts. This capability enables predictive maintenance strategies and rapid troubleshooting of control circuit faults.

Delivery Timeline & Service Commitment

Standard Delivery: In-stock UR8LH modules ship within 1-2 business days via express courier services with full tracking and insurance. Typical delivery times range from 3-7 business days for domestic shipments and 7-14 business days for international destinations, subject to customs clearance procedures.

Custom Configuration: For projects requiring factory configuration, firmware customization, or integration with specialized UR chassis assemblies, lead times typically extend to 4-6 weeks depending on engineering requirements and production scheduling.

Warranty Coverage: Every UR8LH module includes a comprehensive 12-month manufacturer's warranty covering defects in materials and workmanship. Warranty service includes advance replacement for critical applications, with expedited shipping to minimize downtime.

Technical Support: Our engineering team provides pre-sales application consulting, configuration assistance, and post-installation troubleshooting support. Services include relay logic programming guidance, system integration recommendations, and coordination with GE Multilin factory technical support for complex applications.

Documentation Package: Each module ships with installation instructions, wiring diagrams, and technical specifications. Complete UR series manuals, application notes, and configuration software are available for download from our technical resource library.

Frequently Asked Questions

How does the UR8LH relay output module interface with existing SCADA systems?
The UR8LH relay contacts provide hardwired control outputs from the UR series protection relay, which communicates with SCADA systems via Modbus, DNP3, or IEC 61850 protocols through separate communication modules. Relay outputs execute local control actions based on protection logic or remote commands received from SCADA, providing a critical backup control path if communication networks fail.

What is the maximum switching frequency for UR8LH relay contacts?
Under rated load conditions (7A at 30VDC or 250VAC), the UR8LH supports switching frequencies up to 100 operations per minute. For applications requiring higher cycling rates, such as pulse-width modulation or high-frequency sequencing, solid-state output modules should be considered as an alternative to electromechanical relay contacts.

Can the UR8LH module be installed in energized UR chassis without system shutdown?
Yes, when the UR chassis is equipped with redundant power supply modules and configured for hot-swap operation, the UR8LH can be safely inserted or removed during live operation. However, connected control circuits will be interrupted during module replacement, so this procedure should be coordinated with operational requirements and safety protocols.

What are the differences between UR8LH Form-A and UR8RH Form-C relay outputs?
The UR8LH provides eight Form-A (SPST-NO) contacts that are normally open and close when energized, ideal for simple trip commands and enable signals. The UR8RH offers eight Form-C (SPDT) contacts with both normally-open and normally-closed terminals, required for interlocking circuits, fail-safe alarm systems, and applications where both energized and de-energized states must control separate circuits.

How many UR8LH modules can be installed in a single Universal Relay chassis?
The number of I/O expansion modules depends on the specific UR chassis model and CPU module configuration. Standard UR chassis typically accommodate 4-6 expansion modules, while extended chassis support up to 12 modules. Consult the UR series planning guide or contact our engineering team for application-specific configuration recommendations.

Are UR8LH relay contacts suitable for switching inductive loads such as contactor coils?
Yes, the UR8LH is designed for switching inductive loads common in industrial control applications. For highly inductive loads (such as large contactor coils or solenoid valves), install RC snubber networks or varistor suppression devices across relay contacts to extend contact life and minimize electrical noise. Consult GE Multilin application notes for specific suppression recommendations based on load characteristics.

Ready to Enhance Your Protection System?

The UR8LH Relay Output Module delivers the reliability, performance, and flexibility that modern industrial protection and control systems demand. Whether you're designing a new substation automation project, upgrading legacy electromechanical relay panels, or expanding existing UR series installations, this module provides a proven solution backed by GE Multilin's decades of protection relay expertise.

Our technical team is ready to assist with application-specific questions, system configuration recommendations, and integration planning. Contact us today to discuss your project requirements, request detailed technical documentation, or place your order for immediate shipment.

Request a Quote | Technical Consultation | Download Specifications

© 2026 NINERMAS COMPANY LIMITED. All rights reserved.
Original Source: https://ninermas.com
Contact: sale@ninermas.com | +0086 187 5021 5667