Solar service technicians - Don't miss the comprehensive, new Solar PV Ground-fault Troubleshooting: Theory, Tools, and Field Application course!

About this course

This course is a comprehensive exploration of PV system ground faults, focusing on locating, troubleshooting, and repairing them, with an emphasis on practical field applications. The lessons cover both central and string inverter systems - including configurations with harnesses, combiners, and various types of disconnects. Starting off with a review of grounding and bonding, we cover the fundamentals of inverter topologies (transformer-based vs. transformerless) along with their associated grounding and GFDI systems. By the end of the course, you will have a thorough understanding of how different types of ground faults behave and how to safely troubleshoot them using a digital multimeter and insulation resistance tester. 

Learning Objectives

  • Describe how and why PV systems are bonded and grounded.
  • Identify qualities and the function of insulation in PV systems.
  • Describe causes and consequences of faults in PV systems.
  • Describe how to perform insulation resistance testing (IRT) and analyze test results.
  • Identify common PV inverter topologies along with associated protective devices and grounding configurations.
  • Recognize ground-fault current paths and the GFDI functionality for different PV inverter topologies.
  • Identify best practices and safety considerations for ground fault troubleshooting.
  • Outline general procedures for troubleshooting hard and resistive ground faults.
  • Identify how to use a digital multimeter and insulation resistance tester to troubleshoot PV DC ground faults.
  • Describe considerations and procedures for isolating circuits on string and central inverters during DC ground-fault troubleshooting.
  • Outline troubleshooting techniques for hard-to-locate ground faults.
  • Describe considerations and methods for repairing ground faults.

Course outline

14 modules
6 - 7 hours to complete
4:48 hours of video lectures
Welcome • 3 assignments
Orientation Materials

This course is self-paced, so you don’t need to be logged in at any specific time. You can get started immediately after you enroll and the course materials will remain in your account with minimum guaranteed access for 12 months (1 year) after enrollment.

  • Course Introduction (06:48 minutes) Preview
  • Set up email notifications and your student profile
  • Introduce yourself on the discussion board
Module 1 • 6 assignments
Introduction to PV System Grounding and Bonding

  • Distinguish between system grounding and equipment bonding and grounding
  • Recognize the purpose of grounding and bonding in PV systems 
  • Identify common equipment involved in grounding and bonding PV systems

  • Presentation Handout (.pdf)
  • 1.1 Why ground, why bond? (05:30 minutes)
  • 1.2 Equipment Grounding and Bonding (04:22 minutes)
  • 1.3 System Grounding (07:53 minutes)
  • 1.4 Fault Current Paths (03:15 minutes)
  • Knowledge Check
Module 2 • 7 assignments
Insulation, Resistance, and Faults

  • Describe the purpose of conductor insulation 
  • Identify characteristics of common PV system conductor and cable types 
  • Outline the role of insulation in various PV system faults 
  • Describe the different types of PV system ground faults

  • Presentation Handout (.pdf)
  • 2.1 Insulation, Resistance, and Faults (04:17 minutes)
  • 2.2 Insulation Resistance in Electrical Systems (03:26 minutes)
  • 2.3 Typical PV System Conductors and Cables (04:46 minutes)
  • 2.4 Faults and Failures in Electrical Systems (07:15 minutes)
  • 2.5 What is a PV system DC ground fault? (02:58 minutes)
  • Knowledge Check
Module 3 • 10 assignments
Testing Insulation Resistance

  • Explain the purpose of insulation resistance testing (IRT) 
  • Describe how environmental factors such as temperature and moisture affect results 
  • Summarize IRT procedures for conductors and equipment in accordance with industry standards 
  • Summarize IRT procedures for circuits with PV modules 
  • Analyze results of IRT on conductors and circuits with PV modules

  • Presentation Handout (.pdf)
  • 3.1 Fundamentals of Insulation Resistance Testing (IRT) (06:38 minutes)
  • 3.2 IRT Standards and Considerations (08:09 minutes)
  • 3.3 IRT of Conductors (Excluding Circuits with PV Modules) (05:44 minutes)
  • 3.4 IRT of Conductors: Parameters, Results, and Other Tests (06:32 minutes)
  • 3.5 IRT of Circuits with PV Modules (05:26 minutes)
  • 3.6 Expectations and Analysis: Circuits with PV Modules (06:36 minutes)
  • Knowledge Check
  • Additional Resource - Megger IRT Guide (.pdf)
  • Additional Resource - Megger PV Testing Guide (.pdf)
Module 4 • 7 assignments
Inverter Topologies and DC System Grounding

  • Describe the purpose of a PV DC Ground-Fault Detector-Interruptor (GFDI)
  • Differentiate between transformerless and transformer-based inverter topologies
  • Identify the differences in the grounding and protective devices in transformer-based and transformerless inverters

  • Presentation Handout (.pdf)
  • 4.1 Inverter Topologies and DC GFDI (01:56 minutes)
  • 4.2 Transformer-based (Isolated) Inverters (03:42 minutes)
  • 4.3 Transformerless (Non-isolated) Inverters (06:45 minutes)
  • 4.4 Summary and Other Topologies (05:17 minutes)
  • 4.5 A Final Word on Topology (01:42 minutes)
  • Knowledge Check
Module 5 • 6 assignments
Ground-fault Path Scenarios

  • Compare fault current flow for different inverter topologies during positive, negative, and double faults to ground
  • Describe how different inverter and GFDI topologies are able, or unable, to detect ground faults

  • Presentation Handout (.pdf)
  • 5.1 Transformer-based Inverters Fault Scenarios (08:42 minutes)
  • 5.2 Transformerless Inverters Fault Scenarios (03:49 minutes)
  • 5.3 Double Faults with PV Circuits in Parallel (04:18 minutes)
  • Knowledge Check
  • Additional Resource - The Bakersfield Fire (.pdf)
Module 6 • 6 assignments
Fault Voltage and Insulation Resistance

  • Identify fault voltages and locations in PV module circuits using a DMM
  • Identify PV circuits with ground faults or low resistance values using an IRT

  • Presentation Handout (.pdf)
  • 6.1 Voltage Measurements (07:30 minutes)
  • 6.2 Homerun Faults (05:16 minutes)
  • 6.3 Exercise - Find the Fault (01:53 minutes)
  • 6.4 Insulation Resistance Measurements (05:55 minutes)
  • Knowledge Check
Module 7 • 5 assignments
Introduction to Ground-fault Troubleshooting

  • Identify hazards and safety considerations for ground fault troubleshooting
  • Outline best practices and general procedures for ground fault troubleshooting

  • Presentation Handout (.pdf)
  • 7.1 Troubleshooting Tools (01:59 minutes)
  • 7.2 Considerations and Strategies (06:33 minutes)
  • 7.3 Troubleshooting Framework (08:19 minutes)
  • Knowledge Check
Module 8 • 7 assignments
Troubleshooting Hard Faults

  • Summarize procedures for using a DMM to locate hard ground faults
  • Analyze test results and identify fault locations in various scenarios

  • Presentation Handout (.pdf)
  • 8.1 Process Overview (02:34 minutes)
  • 8.2 Mid-string Fault (06:36 minutes)
  • 8.3 Mid-String Fault Continued (04:39 minutes)
  • 8.4 Example 2 Homerun Fault (06:57 minutes)
  • 8.5 Example 3 Burned Open String (04:52 minutes)
  • Knowledge Check
Module 9 • 9 assignments
Troubleshooting Resistive Faults

  • Summarize procedures for using an IRT to locate resistive ground faults
  • Analyze test results and identify fault locations in various scenarios

  • Presentation Handout (.pdf)
  • 9.1 Process Overview (01:09 minutes)
  • 9.2 Example 1: Comparing IRT Values (03:27 minutes)
  • 9.3 Example 1, Continued: Isolate and LOTO (05:07 minutes)
  • 9.4 Example 1, Continued: Comparing IRT Values, Continued Test, Record, and Analyze Results (10:14 minutes)
  • 9.5 Example 2 Locating a Resistive Fault (01:57 minutes)
  • 9.6 Example 2 Locating a Resistive Fault, Continued (05:15 minutes)
  • 9.7 Example 2 Locating a Resistive Fault, Continued: Segment and Repeat (07:22 minutes)
  • Knowledge Check
Module 10 • 6 assignments
Central Inverter Scenarios

  • Identify differences in DC system bonding configurations in central inverters
  • Compare the ability to isolate and segment PV arrays across different central inverter configurations
  • Summarize the fault finding process for PV systems with central inverters

  • Presentation Handout (.pdf)
  • 10.1 GFDI Systems in Central Inverters (06:34 minutes)
  • 10.2 DC System Bonding Point (03:44 minutes)
  • 10.3 Switching and Segmenting (06:05 minutes)
  • 10.4 Fault Finding Process (14:01 minutes)
  • Knowledge Check
Module 11 • 6 assignments
Theory vs Reality: When the Fault Hits the Fan

  • Outline considerations and best practices for troubleshooting intermittent ground faults
  • Recognize the role of wet testing in ground fault troubleshooting
  • Identify considerations for troubleshooting double ground faults

  • Presentation Handout (.pdf)
  • 11.1 Intermittent Faults (04:01 minutes)
  • 11.2 Wet IRT and Wet Equipment (08:02 minutes)
  • 11.3 Double and Multiple Faults (02:48 minutes)
  • 11.4 Sometimes you just can't find the fault... (02:19 minutes)
  • Knowledge Check
Module 12 • 8 assignments
Remediating and Repairing Ground Faults

  • Identify common ground fault indicators, locations, and causes
  • Describe appropriate repair methods for different fault scenarios

  • Presentation Handout (.pdf)
  • 12.1 Overview of Repairing Ground Faults (03:07 minutes)
  • 12.2 Internal to Module (03:07 minutes)
  • 12.3 Module Leads and Connectors (02:50 minutes)
  • 12.4 Free-air and/or Above Ground DC Distribution, Including String Homeruns (01:50 minutes)
  • 12.5 Enclosed and/or Underground DC Distribution (03:21 minutes)
  • 12.6 Final Steps (01:58 minutes)
  • Knowledge Check
Conclusion • 5 assignments
Feedback and Additional Resources

This is our last module but you still have access to the all of course materials for 12 months (1 year), so keep working and you'll be able to complete the course at your own pace. After your year of access expires you can optionally extend access with a HeatSpring Membership. Enjoy the course and keep in touch!

  • Wrap Up (01:00 minutes)
  • 1 Year of Access to Course Materials
  • Feedback: 2-minute Exit Survey
  • Consider Joining as a HeatSpring Member
  • Certificate of Completion: Request a Certificate

Instructors

Rebekah Hren

Senior Consultant , Solar Tech Collective

Rebekah Hren has over twenty years of experience working in the solar and electrical industry. She is a qualified master electrician, and has served as a principal voting member on Code-Making Panel 4 for NFPA 70 (National Electrical Code) since 2017.  She is a NABCEP board member and certified PV Installation Professional . Since 2007 she’s enjoyed teaching PV system...

Alex Jahp

Senior Consultant, Solar Tech Collective

Alex Jahp joined the solar industry in 2015 out of a passion for the environment, climate change, and sustainable development. He has since worn many hats – and hard hats – with roles in construction, design, and project management on projects from watts to megawatts throughout the US, Peru, and Guatemala. His work has taught him the important role that codes,...

Brian Mehalic

Senior Consultant, Solar Tech Collective

Brian Mehalic is a NABCEP-certified PV Installation Professional with over 22 years of experience designing, installing, inspecting, and servicing all types and sizes of PV and energy storage systems. He began his career as Lead Technician and Project Manager at EV Solar Products in Arizona then worked as Project Engineer for O2 Energies in North Carolina. He was a...

Frequently asked questions

Full FAQ
How does this course work?
You can begin this online course instantly upon enrollment. This course is delivered entirely online. Pre-order courses are available on launch date. This course is self-paced and you can set your own schedule to complete the materials. You can begin the lecture videos and other course materials as soon as you enroll. During your year of access the instructor will be in the course answering questions on the discussion board. After successfully completing the course, you will be able to generate a certificate of completion.
How long do I have access to the materials?
Students get unlimited access to the course materials as soon as they enroll and for one year (365 days) after enrollment. Rewatch videos and review assignments as many times as you want. View updates the instructor makes to the course as the industry advances. Return to your course anytime with online access from anywhere in the world. After the one year of access expires, access can be extended by joining as a HeatSpring member. A single membership extends access to course materials for all past enrollments.
Will the instructor really answer my questions during this course?
Yes! This is an instructor-led online course. You can ask questions on the discussion board and get prompt answers from your instructor. It varies by instructor and by course but typically instructors check-in between daily and weekly to check quiz results or project work, review and respond to discussion board questions and read survey responses. Check the enrollment page for specific information about each instructor's check-in frequency.
Is there a certificate of completion?
Yes, when you complete this course you are eligible for a certificate of completion from HeatSpring. You can download your certificate as soon as you have completed all of the course requirements. Students can easily share their verified certificates on their LinkedIn profiles using our LinkedIn integration.
Can I register multiple people?
Yes, please visit our For Teams page to get a group discount.

$595

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