Describe the difference between 'nominal' and 'surveillance' tests in NANTeL.

• A. Nominal tests verify ongoing health of channels.
• B. Surveillance tests verify normal functionality.
• C. Nominal tests verify normal functionality; surveillance tests verify ongoing health and condition of channels and components on a periodic basis.
• D. Nominal tests verify ongoing health of channels.

Answer: (D)

Nominal tests are about confirming that the protection system operates correctly under normal, expected conditions—verifying that the channels and logic respond as designed when inputs are within their normal range. Surveillance tests, by contrast, are periodic checks that monitor the ongoing health and condition of the channels and components, catching degradation or drift before a fault occurs. The pairing described—nominal tests for normal functionality and surveillance tests for ongoing health and condition on a periodic basis—best captures the distinction. The idea that nominal tests verify ongoing health would mix up the roles, since that health monitoring belongs to surveillance testing.