Factory acceptance testing best practices

A factory acceptance test (FAT) for the system and issuing a certificate of conformity on both operation and function is critical.

By Dr. Michael Wrinch February 10, 2022
Courtesy: Hedgehog Technologies

Testing equipment before it’s in the field is safer, more efficient, and saves the project money. It is a common situation where everyone is in a rush and wants to get the product in the field as soon as possible and then bring contractors on-site to figure out what the next steps are. This can work for low-value, single-control panels that are located close to the team’s home base but in remote locations such as for mines, mills, amusement parks, and indigenous communities it is not so easy.

For example, take this protection relay we tested in our office before heading out to a remote location for commissioning. Not only can we spend a few calm days in our office with a precision relay tester verifying every function with both the engineer and principal engineer’s oversight, but we can adjust as needed and avoid the risk of damaging any equipment when initially energizing the system.

In this case, we discovered that all the settings were correct but the triggering logic was not enabled and the system would not have properly functioned. We cannot stress enough the importance of running a factory acceptance test (FAT) for the system and issuing a certificate of conformity on both operation and function.

Similarly, for the production of multiple complex control items, FAT is critical. For example, to ensure our customers got a working system, we built a machine to verify every single input, output, feedback, and control capacity of a motion control system. We called it the Panel Factory Acceptance Tester (P-FAT). When it arrives on-site with 50 other similar items they can run as intended with no further issues and we can prove the product meets the system specification when it leaves the factory.

A FAT is good practice because it proves the product runs safely and can manage cost risk by preventing on-site delays caused by missing equipment, wiring errors, or faulty setup. All of which require additional contractors and engineers to support the work or for additional parts to be ordered or modified. This can delay the project and ultimately eat into the budget by causing a ripple effect of the delay with interdependent tasks. Project efficiency aside, it is safer in the long term and during energization.

– This originally appeared on Hedgehog Technologies’ website. Hedgehog Technologies is a CFE Media and Technology content partner. Edited by Chris Vavra, web content manager, Control Engineering, CFE Media and Technology, cvavra@cfemedia.com.


Dr. Michael Wrinch
Author Bio: Dr. Michael Wrinch, P.Eng., is the president of Hedgehog Technologies, an electrical engineering consulting firm that specializes in risk management. He is certified through TÜV Rheinland, an international gold standard in safety.