GE UR4LA Digital Input/Output Module

Configured for high-speed signal integration in Universal Relay (UR) control platforms, the GE UR4LA (UR4LA Digital Input/Output Module) provides direct physical/electrical execution of 8-channel optically isolated digital input monitoring and 4-channel Form A high-speed output switching.

Hardware Specifications

GE Industrial Power Protection Characteristics

• SIL3 certification: The UR4LA architecture is designed to support safety-critical relay logic. Its high-speed outputs are engineered for deterministic trip execution, ensuring that breaker control and protective interlocking logic meet the stringent timing requirements of power grid safety standards.
• Triple modular redundancy (TMR) 2oo3 architecture: Within the Universal Relay platform, the module supports integration into TMR protection schemes. This provides fault-tolerant signal acquisition, where the system executes voting logic on digital inputs to ensure that a single component failure does not lead to a spurious protective trip.
• Galvanic isolation: The inputs feature optical isolation to decouple field-level signaling from the internal processing logic of the UR relay. This is mandatory to maintain signal integrity against high-frequency transients and surge events common in substation environments.
• Fail-safe state execution: The output relay contacts are designed to transition to a predefined safe state upon loss of control power or module fault, ensuring that protective signaling is maintained during system-level contingencies.

Frequently Asked Questions

Q: Is the UR4LA module hot-swappable while the UR relay is in an active protection state?

A: Yes, the UR4LA is designed for hot-swapping within the UR chassis. The backplane interface is engineered to allow safe removal and insertion without de-energizing the main relay CPU or interrupting the protection functions of other installed modules.

Q: Can the 48 VDC input channels be triggered by higher voltage levels if current-limited?

A: No. The input circuitry is specifically rated for a nominal 48 VDC (range 30–60 VDC). Exceeding these thresholds risks damaging the optical isolation components. Ensure external signal sources are properly clamped to these voltage ratings.

Field Installation Guidelines

• Mounting: Slide the module into the designated UR chassis slot and secure the retention screws. Ensure the backplane connector is fully seated, which is mandatory for reliable communication between the module and the UR relay’s central processor.
• Grounding: Secure the UR chassis to the substation’s primary earth grid using low-impedance conductors. A consistent ground reference is mandatory for the effectiveness of the module's optical isolation and surge withstand capability (SWC) against transient power system noise.
• Wiring: Connect digital inputs and outputs using shielded, twisted-pair cabling. Maintain at least 150 mm separation from high-voltage primary circuits to prevent EMI induction, which is mandatory to protect the input stages from false triggers or hardware damage.