GE UR6NA CT/VT Module

Configured for power system signal acquisition in Universal Relay (UR) platforms, the GE Multilin UR6NA (UR6NA CT/VT Module) provides direct physical/electrical execution of current and voltage transformer signal conversion for protection and control loops.

Hardware Specifications

Industrial Control and Network Characteristics

• Backplane bus communication velocity: The module utilizes the high-speed Universal Relay backplane to transmit digitized waveform data to the main processing unit. This velocity is necessary for supporting sub-cycle protection algorithms, such as 87L differential protection, which typically executes in less than 1 cycle.
• Profinet / EtherNet/IP deterministic networks: The UR6NA integrates into networks supporting IEC 61850, DNP 3.0, and Modbus RTU protocols. This allows for high-speed interoperability and deterministic data exchange with SCADA and station-level automation systems.
• I/O density scaling: The module supports flexible scaling of current and voltage inputs, with configurations accommodating up to 11 CTs and 4 VTs, enabling the construction of complex protection schemes within a singular relay chassis.
• Firmware flash compatibility: The hardware platform supports field-level firmware upgrades, ensuring the module remains aligned with evolving communication standards (PRP/HSR) and protection logic requirements without hardware replacement.

Frequently Asked Questions

Q: Is the UR6NA hot-swappable during system operation?

A: Yes, the UR6NA is designed for hot-swapping within the UR relay chassis. The backplane design enables the insertion or extraction of the module while the system is energized, provided that local safety procedures regarding CT/VT circuit isolation are strictly followed.

Q: Can the CT input ratings be modified via software?

A: The physical CT input hardware is typically fixed to 1A or 5A ratings. While software configuration is used for scaling and primary-to-secondary ratio setting, ensure the hardware hardware jumpers or model selection matches the physical CT secondary rating to prevent measurement errors.

Field Installation Guidelines

• Mounting: Insert the module into the designated UR relay slot and secure the locking levers. Ensure the backplane connector is fully mated to maintain the high-integrity contact required for low-level CT and VT signal paths.
• Grounding: The UR chassis must be connected to the substation earth bus via a low-impedance ground strap. A solid ground connection is mandatory to prevent electromagnetic interference (EMI) from affecting the analog-to-digital conversion process.
• Wiring: Use shielded, twisted-pair cabling for all CT and VT inputs. Route these signal lines through dedicated conduit, ensuring a minimum separation of 150 mm from high-voltage AC lines to mitigate inductive noise coupling that can cause maloperation of protection elements.