GE CT/VT8H UR8HH Relay Contact Module

Product Details

CT/VT8H UR8HH Product Description

The GE CT/VT8H UR8HH is a precision-engineered relay contact module designed for seamless integration within the GE UR Series protection and control platform. As a dedicated current transformer (CT) and voltage transformer (VT) input module, the CT/VT8H UR8HH serves a foundational role in the signal acquisition layer of substation automation and industrial protection architectures. Its eight-channel CT/VT input capacity enables high-density signal termination within a single rack slot, reducing wiring complexity while maintaining the signal fidelity required for accurate protective relay operation across transmission, distribution, and industrial power systems.

Within a complete UR Series chassis, the CT/VT8H UR8HH operates in direct coordination with the UR CPU module — such as the UR F35 Multi-Loop Controller or UR F60 Feeder Protection Relay — which processes the analog signals acquired through this contact module and executes protection algorithms including overcurrent, differential, distance, and directional protection schemes. The module's analog front-end is calibrated to match the UR platform's internal signal conditioning chain, ensuring that measurement accuracy and phase alignment are preserved across the full dynamic range of the connected CT and VT circuits.

Signal integrity from the CT/VT8H UR8HH feeds directly into the UR platform's I/O coordination layer, where digital output modules such as the UR DO8H and UR DO16H translate protection decisions into trip and close commands for circuit breakers, contactors, and motorized disconnects. This tight coupling between the analog input layer and the digital output layer is what enables sub-cycle fault clearance times and deterministic relay response — critical performance parameters in high-availability power infrastructure and process-critical industrial installations.

The module is rack-mounted within the standard UR Series chassis backplane, which supports hot-swap capability for select module types and provides the internal communication bus connecting all installed modules to the UR CPU. This backplane architecture allows the CT/VT8H UR8HH to be deployed alongside communication gateway modules — including the UR IEC 61850 GOOSE messaging module and the UR DNP3 serial communication module — enabling the protection system to participate in station-wide automation schemes, inter-relay communication, and SCADA integration without additional signal conversion hardware.

In redundant protection architectures, the CT/VT8H UR8HH supports dual-redundant CT/VT input configurations where primary and backup protection relays share the same physical CT/VT circuits through dedicated summation or isolation arrangements. This design pattern is standard in busbar protection, transformer differential protection, and generator protection schemes where single-point failure in the signal acquisition layer must be eliminated. The module's robust analog input circuitry is designed to withstand CT open-circuit transients and VT ferroresonance conditions that are common in high-voltage substation environments.

Power supply integrity for the UR chassis is maintained by the UR PS module, which provides regulated DC power to all installed modules including the CT/VT8H UR8HH. In critical installations, redundant power supply modules are deployed within the same chassis to eliminate power-related single points of failure. The CT/VT8H UR8HH's low power consumption profile is compatible with both standard and redundant UR power supply configurations, supporting installations in thermally constrained control panels and compact relay rooms.

For HMI and local operator interface, the UR Series platform integrates with the GE EnerVista UR Setup software suite, which provides graphical configuration, real-time metering, event recording, and oscillography retrieval directly from the UR CPU. The CT/VT8H UR8HH's channel assignments, CT ratio compensation, and VT scaling factors are all configured through EnerVista, with settings stored in non-volatile memory within the UR CPU module. This centralized configuration model simplifies commissioning and ensures that CT/VT input parameters remain consistent across firmware upgrades and module replacements.

Long-term maintenance efficiency is a core design principle of the UR Series platform. The CT/VT8H UR8HH is a field-replaceable module with a standardized form factor, allowing maintenance teams to swap the module without disturbing adjacent modules or the chassis backplane. Replacement modules are pre-configured using EnerVista settings files, reducing commissioning time during emergency maintenance windows. All CT/VT8H UR8HH units supplied by NANKMOS are tested prior to shipment and covered by a 12-Month Warranty, with global inventory availability supporting both planned maintenance schedules and unplanned replacement requirements.

The CT/VT8H UR8HH achieves its full system value when deployed as part of a coordinated UR Series automation platform. In a typical substation bay protection scheme, the module operates alongside the UR F35 Multi-Loop Controller for feeder and motor protection, the UR F60 Feeder Protection Relay for distribution feeder applications, and the UR T35 Transformer Protection Relay for power transformer differential and overcurrent protection. The CT/VT8H UR8HH provides the analog signal acquisition foundation that all of these CPU modules depend upon for accurate protection element operation.

At the digital output layer, the UR DO8H digital output module and UR DO16H high-density output module translate the protection decisions processed by the UR CPU into physical trip and close signals for circuit breakers and contactors. The UR DI16H digital input module simultaneously monitors breaker status, protection relay auxiliary contacts, and process interlock signals, completing the I/O loop that enables closed-loop protection and control automation.

Communication integration is handled by the UR IEC 61850 communication module, which enables GOOSE messaging for inter-relay tripping and station bus integration, and the UR DNP3 serial communication module for legacy SCADA connectivity. In installations requiring time synchronization for event recording and fault analysis, the UR IRIG-B time synchronization module provides GPS-referenced timing to the entire UR chassis, ensuring that oscillography records from the CT/VT8H UR8HH's analog inputs are accurately time-stamped for post-fault analysis.

Power supply redundancy is achieved through dual UR PS24 or UR PS125 power supply modules installed in the same chassis, providing N+1 power redundancy without interrupting module operation. For installations requiring panel-level power distribution, GE MPCV series miniature circuit breakers provide coordinated overcurrent protection for the DC supply circuits feeding the UR chassis.

The GE CT/VT8H UR8HH is deployed across a broad range of industrial and utility power system applications where accurate CT/VT signal acquisition is critical to protection system performance. In electric utility transmission and distribution substations, the module supports line protection, busbar protection, and transformer protection schemes where multiple CT/VT inputs must be processed simultaneously within a single relay chassis. The eight-channel input capacity of the CT/VT8H UR8HH is particularly well-suited to multi-feeder bay protection applications where a single UR CPU module manages protection for multiple circuit elements.

In industrial power systems — including petrochemical plants, steel mills, mining operations, and large-scale manufacturing facilities — the CT/VT8H UR8HH supports motor protection, generator protection, and medium-voltage switchgear protection applications. These environments demand relay modules that can withstand high ambient temperatures, vibration, and electromagnetic interference while maintaining measurement accuracy across the full range of fault and load conditions. The CT/VT8H UR8HH's robust analog input design meets these requirements, making it a reliable choice for harsh industrial environments.

In offshore and marine power systems, the module's wide operating temperature range and compliance with international electrical standards support deployment in vessel power management systems and offshore platform electrical protection schemes. For water treatment and pumping stations, the CT/VT8H UR8HH enables motor and feeder protection within compact control panels where space efficiency and long-term reliability are primary design constraints. In renewable energy integration applications, the module supports protection relay systems at wind farm collector substations and solar plant medium-voltage switchgear, where accurate CT/VT signal acquisition is essential for grid interconnection protection compliance.

Q1: Is the CT/VT8H UR8HH compatible with all UR Series chassis and CPU modules? The CT/VT8H UR8HH is designed for the GE UR Series platform and is compatible with standard UR chassis backplanes. Compatibility with specific CPU modules — including the F35, F60, T35, and other UR family relays — should be verified against the UR Series hardware compatibility matrix for the target firmware version. NANKMOS technical support can assist with compatibility verification prior to order placement.

Q2: Can the CT/VT8H UR8HH be replaced in the field without full system shutdown? The UR Series platform supports module-level replacement procedures that minimize system downtime. In installations where the UR chassis supports hot-swap for analog input modules, the CT/VT8H UR8HH can be replaced with pre-configured replacement units using EnerVista settings files. For installations where hot-swap is not supported, planned maintenance windows should be scheduled. All replacement units supplied by NANKMOS are pre-tested and covered by the 12-Month Warranty, reducing commissioning risk during replacement operations.

Q3: What is the lead time and warranty coverage for the CT/VT8H UR8HH? NANKMOS maintains global inventory of the GE CT/VT8H UR8HH to support both planned procurement and emergency replacement requirements. Standard lead times for in-stock units are 3–7 business days for international shipments, with expedited shipping options available. All units are covered by a 12-Month Warranty from the date of shipment, covering manufacturing defects and module functionality. Pre-shipment testing is performed on all units to verify analog input channel performance prior to dispatch.