Which of the following is NOT listed as a mitigation for spurious trips in NANTeL?

• A. Channel diversity
• B. Redundant power supplies
• C. Filtering
• D. Surveillance tests

Answer: (B)

Spurious trips come from false signals or faults in the protection channels, so the mitigations focus on ensuring the sensing and processing paths don’t generate a trip when there isn’t a valid abnormal condition. Channel diversity helps by not relying on a single type of sensor or path, so a fault in one channel is unlikely to cause a trip across all channels. Filtering reduces the chance of reacting to noise or transient spikes in the signals, which are common sources of false trips. Surveillance tests are regular checks that catch drifting performance or degraded channels before they cause an unwanted trip.

Redundant power supplies, while important for keeping the protection system available during power interruptions, don’t directly prevent spurious trips. They improve overall reliability but don’t address false trip triggers caused by sensor faults, noise, or processing errors.