Solar PV Maintenance Exam Prep Exam Questions & Answers 2026 (11–20)

Question 1

What test should be performed before connecting PV module strings in parallel?

TheoryPractice · Accepted Answer

Voltage measurement to verify similar voltages between strings. Voltage measurements should be performed to verify that all strings have similar voltages before connecting them in parallel. Significant differences could indicate wiring errors or module issues.

Question 2

What is the most likely cause if measured string open circuit voltage (Voc) is significantly lower than expected?

TheoryPractice · Accepted Answer

Module connection issues such as shorts or incorrect series connections. Significantly lower than expected Voc typically indicates module connections issues, such as shorted modules or incorrect series connections, which affect the cumulative voltage of the string.

Question 3

When testing AC voltage at the output of a single-phase inverter in the United States, what is the expected nominal voltage?

TheoryPractice · Accepted Answer

240V. In the United States, the nominal AC voltage for a single-phase inverter output is typically 240V, which is the standard residential service voltage.

Question 4

What is the purpose of performing continuity testing during PV system commissioning?

TheoryPractice · Accepted Answer

To verify there are no breaks in the electrical path throughout the system. Continuity testing verifies that there are no breaks in the electrical path throughout the system, ensuring proper connections between components and identifying any open circuits that could affect performance.

Question 5

When measuring insulation resistance, what voltage setting should typically be used for a 600V DC PV system?

TheoryPractice · Accepted Answer

1000V DC. For a 600V DC PV system, the test voltage for insulation resistance testing should be 1000V DC, which provides adequate stress to detect insulation weaknesses without exceeding system ratings.

Question 6

What should be done before conducting an insulation resistance test on a PV array?

TheoryPractice · Accepted Answer

Disconnect all surge protection devices. Before conducting an insulation resistance test, all surge protection devices must be disconnected to prevent damage to the SPDs and to ensure accurate measurement of the insulation resistance.

Question 7

Which device is used to verify the torque applied to electrical terminations?

TheoryPractice · Accepted Answer

Torque screwdriver or wrench. A torque screwdriver or wrench is used to apply and verify the specific torque required for electrical terminations, ensuring connections are tight enough for good contact but not over-tightened.

Question 8

What action should be taken if measured short circuit current (Isc) is significantly higher than expected?

TheoryPractice · Accepted Answer

Recheck the irradiance measurement and calibration of testing equipment. If measured Isc is significantly higher than expected, the commissioning specialist should recheck the irradiance measurement and calibration of testing equipment, as high current could indicate measurement errors or unusually high irradiance conditions.

Question 9

What is the primary reason for measuring AC voltage at both no-load and full-load conditions?

TheoryPractice · Accepted Answer

To identify excessive voltage drop under load. Measuring AC voltage at both no-load and full-load conditions helps identify excessive voltage drop under load, which could indicate undersized conductors or connection issues that may affect system performance.

Question 10

When conducting electrical tests on a PV system, what information must be recorded along with test results according to IEC 62446-1?

TheoryPractice · Accepted Answer

Test dates, environmental conditions, and test equipment details including calibration information. According to IEC 62446-1, test dates, environmental conditions (temperature, irradiance), and test equipment details including calibration information must be recorded with test results for proper documentation and future reference.

Solar PV Maintenance Exam Prep Exam Questions & Answers 2026 (11–20)

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