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Free NABCEP-PVIP Practice Questions

10 free, exam-style NABCEP PV Installation Professional (NABCEP-PVIP) practice questions with answers and explanations. No signup required. Work through them below, then take the full free NABCEP-PVIP practice test to study every exam domain.

The NABCEP-PVIP exam has 70 questions and runs 4 hours.

These 10 free NABCEP-PVIP questions are organized by exam domain, so you can see how each part of the NABCEP PV Installation Professional blueprint is tested. Reveal the answer and explanation under each question.

Domain 1: Conducting a Site Assessment

Question 1

An inverter has a maximum DC input voltage of 600V. Modules have Voc_STC = 41.0V and a Voc temperature coefficient of -0.25%/°C. The ASHRAE extreme minimum temperature is -25°C. What is the maximum number of modules per string?

  1. 12
  2. 14
  3. 13
  4. 15
Show answer & explanation

Correct answer: C - 13

Question 2

A residence has a 175A main breaker on a 200A busbar. The maximum PV backfeed breaker per the 120% rule is:

  1. 25A
  2. 65A
  3. 50A
  4. 40A
Show answer & explanation

Correct answer: B - 65A

Question 3

A PV module has Isc = 10.4A. The minimum conductor ampacity for the source circuit per NEC 690.8 is:

  1. 10.4A
  2. 13.0A
  3. 20.8A
  4. 16.2A
Show answer & explanation

Correct answer: D - 16.2A

Domain 2: System Design (Mechanical and Electrical)

Question 4

PV modules produce DC voltage whenever exposed to light. This means:

  1. PV modules can be safely handled with bare hands at any time
  2. Covering modules with cardboard completely eliminates all voltage
  3. PV modules only produce voltage when connected to an inverter
  4. PV modules remain energized during daylight and cannot be de-energized by opening disconnects
Show answer & explanation

Correct answer: D - PV modules remain energized during daylight and cannot be de-energized by opening disconnects

Question 5

A proper flashing installation for a composition shingle roof mount requires the flashing to be:

  1. Slid under the shingle course above and over the shingle course below
  2. Placed over the shingle course above and under the shingle course below
  3. Installed between adjacent shingle courses at the same horizontal level
  4. Secured under both the upper and lower shingle courses simultaneously
Show answer & explanation

Correct answer: A - Slid under the shingle course above and over the shingle course below

Question 6

The correct sequence for Lock-Out/Tag-Out in a PV system is:

  1. Lock → Tag → Verify → Shut down
  2. Shut down → Lock → Notify → Verify
  3. Verify → Lock → Tag → Shut down
  4. Identify → Notify → Shut down → Isolate → Lock/Tag → Verify
Show answer & explanation

Correct answer: D - Identify → Notify → Shut down → Isolate → Lock/Tag → Verify

Domain 3: Applicable Codes, Standards, and Best Practices

Question 7

A 10 kW (STC) system at commissioning with irradiance of 850 W/m² and an overall system derating factor of 0.80 should produce approximately:

  1. 10.0 kW
  2. 6.8 kW
  3. 8.5 kW
  4. 4.3 kW
Show answer & explanation

Correct answer: B - 6.8 kW

Question 8

A 10-module string reads 325V when all other identical strings read 360-370V under the same conditions. The MOST likely cause is:

  1. Normal temperature variation between strings
  2. The inverter is limiting the string voltage
  3. The string has an extra module
  4. One module is not contributing voltage
Show answer & explanation

Correct answer: D - One module is not contributing voltage

Domain 4: Installation (Mechanical and Electrical)

Question 9

During an annual inspection, a thermal image shows one cell in a module at 85°C while surrounding cells are at 55°C. This hot spot indicates:

  1. Normal cell-to-cell variation within acceptable operating parameters
  2. Thermal camera calibration error or environmental interference affecting readings
  3. Maximum power production indicating optimal cell performance and efficiency
  4. A potential cracked cell, defective solder joint, or localized shading issue
Show answer & explanation

Correct answer: D - A potential cracked cell, defective solder joint, or localized shading issue

Question 10

A monitoring platform shows a sudden drop to zero production on a sunny day across ALL strings simultaneously. The MOST likely cause is:

  1. All modules failed simultaneously due to manufacturing defect
  2. Cloud cover blocking sunlight across the entire array
  3. A system-wide electrical fault such as tripped breaker or inverter failure
  4. A single module shading event affecting the entire system
Show answer & explanation

Correct answer: C - A system-wide electrical fault such as tripped breaker or inverter failure

The rest of the NABCEP-PVIP blueprint

The NABCEP-PVIP exam also covers these domains. Drill them in the full free practice test:

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