A Control Design reader writes: As we gear up for the reopening of IMTS in Chicago, it reminded us of a previous year, pre-pandemic, when our machinery was largely inoperable for the first day of the show because we were unable to diagnose problems on-site, even though our factory acceptance testing (FAT) went fine.
Any recommendations on a list of diagnostic tools to be sure to have? You’d think setting up at a trade show would be like a site acceptance test (SAT), but it’s not entirely the same. What variables do other manufacturers encounter?
Our machines often go from our own facility, where we do a FAT, to the show floor, where we do a sort-of SAT. From there, the equipment is typically disassembled and sent directly on to a customer’s factory, where it’s reassembled and another SAT is performed, and then commissioning.
What are the must-have tools we need to bring for diagnostics and troubleshooting? And what are the uncommon ones that we might be glad we had with us, so we avoid another lost day at a trade show, or worse?
Also read: Are all factory acceptance tests alike?
Answers
Generate the test spec
Site acceptance testing (SAT) is the process of ensuring that the system is fully operational.
Several topics need to be considered when determining the contents of the SAT. The first point, and arguably the most important, is to consider the safety implications that the project may have on the system. Are there any new safety devices being added? Will the functionality of the system tie into an existing safety circuit? Has the location of all safety devices been thoroughly vetted to ensure ease of access in emergency situations? Once these questions have been answered, the plans for testing the safety aspect of the project can be developed.
Secondly, the complexity of the project needs to be considered. For a simple project, the contents of the SAT could simply be a successful restart of the system. Does it work? Larger, more complex projects will likely require a more thorough means of testing. In this instance, several things could be considered as the final acceptance. It could be a predefined production rate, the quality of the product, maintaining the previous ODE rates for a predetermined amount of time or any combination thereafter.
A common misconception with regards to the SAT is that it is executing the same steps that were performed at the factory acceptance test (FAT). While this would be an absolutely foolproof way of executing the SAT, the reality is that it is an extremely time-consuming process that may not be justified and/or granted.
The system needs to be back in service as quickly as possible. For a more complex system that endured an extensive FAT, performing those same steps for the SAT is presumably not an option. Nor is it necessarily required. Every interlock, permissive, alarm and/or function of the project was already tested at the FAT, so it isn’t really required to be tested again at the SAT. The SAT should be focused on the operation of the actual system and ensure that the quality product is produced.
Other action items that need to be documented are any requirements due to unforeseen consequences or inoperable items that are not critical to running the system. Documenting them ensures that they will be followed up on to determine the course of action and to see the project to completion. Whatever the reasoning for the specific item is, the design team needs to ensure that approval from the client is provided once these items are eventually tested.
In today’s fast-paced, ever-changing manufacturing world, it is important to execute the activities of a project that ensure no stone was left unturned. Site acceptance testing provides a well-documented way to ensure that the scope of a project was met. Careful planning and execution of the site acceptance test ensures not only that the project deliverables were met, but it also provides a means of confidently bringing the system back into operation.
Daniel Weiss / senior product manager / Newark
Test for issues
Setting up machinery at a trade show can come with some unknowns, especially around the power supply. Start there by testing the power supply with a digital multimeter—you’re looking at voltage specifically to ensure it meets the requirement for your machinery. Once you verify that your power supply is good and complies with the machine requirements, follow your normal machine setup process. If you have issues with the machine, they likely emanate from the machine itself, not from the power supply. You can troubleshoot some of the most common machine issues with the digital multimeter, an insulation resistance tester and contact thermometer. If your machine requires balancing, consider a vibration tester, as well.
Sean Silvey / product specialist / FlukeÂ
