Factory acceptance testing is crucial when integrating advanced technologies into a project. When Burns & McDonnell was constructing the 100-megawatt battery energy storage system (BESS) for a confidential client, the need for dependable equipment was significant.

Designing and building the project during the COVID-19 pandemic posed complications for evaluating essential equipment. Fortunately, the firm’s global footprint enabled an efficient solution to that problem.

Inverters are key components of energy storage projects because they convert the direct current (DC) power stored in the batteries to alternating current (AC) power and deliver it to the grid as required. The inverters’ safe, dependable performance is critical to the secure operation of the BESS facility.

The inverters were procured from a factory in Banguluru, India. Because of pandemic restrictions, project team members from the U.S. were unable to travel to India to perform the factory acceptance testing. The good news for our utility client was that we have qualified professionals based in our Mumbai office who could perform the work efficiently and avoid unnecessary delays to the project schedule.

It was important to plan early for the factory acceptance testing in order to see that the factory team would have the inverter skids available at the appointed time. This also allowed us to mutually agree upon the testing procedures in advance. These preparations enabled the factory team to arrange for the required equipment, tools and human resources to be available for the testing.

Our factory acceptance testing criteria are built around factors like applicable codes and standards, OEM recommendations and standard tests, as well as project-specific requirements. Discussions with vendors and the client during the bid phase of the project were critical in finalizing test plans.

With procedures in place, the inverters were put through a progression of tests for:

  • Cabinet and mechanical structure quality
  • Dielectric strength
  • Ground resistance (protection connection)
  • Communication function
  • Conversion efficiency
  • Total harmonic distortion
  • LCD touchscreen operation
  • Reliable operation
  • Smoke sensor signal node
  • Access control system signal node
  • Automatic startup/shutdown
  • Default settings
  • Black start capability

These tests were vital to identify any issues with the equipment that could have detrimental effects on the project schedule or cost. The earlier any concerns were caught, the easier and faster it would be to adapt, adjust and correct course.

In this instance, we also saw that the bushings were tested with the help of a torque testing tool, confirming the torque values matched vendor specifications. If inverter bushings were damaged at the project site due to over-torquing, we would then need to replace bushings or an entire inverter, incurring schedule and cost impacts. Factory acceptance testing in India — earlier in the project process and prior to shipment — helped mitigate this potential problem, avoiding those impacts and helping the project maintain its aggressive schedule. (Indeed, given ongoing backups and delays at maritime ports, any precautions to avoid defective or damaged equipment are important to maintain project schedules.)

Instead, construction of the facility was completed in 10 months, three months ahead of schedule, despite supply chain and shipping constraints during the pandemic.

Working with a fully integrated engineer-procure-construct (EPC) team offers significant advantages to clients eager for fast, efficient project outcomes. Beyond providing a single source of accountability, a fully integrated EPC partner also streamlines projects by bringing together multiple disciplines and capabilities under one roof. When that roof extends across oceans for truly global impact, as in the case of Burns & McDonnell and its large team of experienced professionals in India, the international coordination and travel-related schedule savings can contribute to impressive bottom-line results.


From project development and permitting through to interconnection, construction and startup, utilizing an integrated EPC partner is imperative to creating a more seamless, predictable and cost-effective experience.

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Bhavesh Shimpi is a department manager at Burns & McDonnell India, working on electrical engineering projects for energy clients. He specializes in factory acceptance testing of power transformers and solar photovoltaic panels. He has experience in detailed engineering design for industrial facilities ranging from power plants (conventional and renewable) and petrochemical facilities to aluminum smelters and data centers.