GE Multilin | UR 8NH | Versatile CT/VT Module

The GE Multilin UR-8NH is a versatile CT/VT (current transformer and voltage transformer) module within the UR Series Universal Relay.

Applications

• Overcurrent protection
• Voltage protection
• Motor control
• Power quality monitoring
• Fault detection

Enhanced Diagnostics

• The UR-8NH features enhanced diagnostics capabilities.
• It can detect internal failures of the CT/VT module, raise alarms, and block tripping from associated protection functions.
• This functionality has been field-proven since 2006.

Analog Data Integrity Validation

• The CT/VT input modules (8L, 8M, 8N, 8R, 8S, 8V) use an analog data integrity check.
• An additional analog hardware channel computes the “Mean Square” of the difference between analog channels.
• If the difference exceeds an adaptable error boundary, protection functions using the measured data are momentarily blocked.
• The relay’s self-test alarm contact operates, and the relay is taken out of service if the error persists.

Power Supply Monitoring

• The module continuously checks the power supply voltage against a safe operating reference voltage.
• This ensures that all electronic components operate within safe conditions.