Why Should You Invest in a Factory Witness Test?

AUGUST 2, 2021


by Michael Ruhe, Product Manager Engineered Solutions

It is expected that any manufactured machinery be fully inspected when it leaves the manufacturing floor with appropriate quality assurance tests and inspections to assure conformance/adherence to equipment specifications.


This may be an adequate appraisal for standard equipment, but for highly customized and/or critical infrastructure equipment for mission critical applications, it is advisable to consider further testing. 


Vital equipment such as generators and uninterruptible power supplies that are responsible for delivering backup power in the event of utility power loss are frequently, and understandably, candidates for specific and individualized testing procedures performed at the factory with the end user (and any associated design firms, specifiers, and/or integrators) present to ensure that installation and commissioning in the field will go smoothly later on.


These are referred to as Factory Acceptance or Factory Witness Tests, which may also include the associated peripheral equipment, such as the DC power solution and switchgear that will be part of the installation.



The main objective of the Factory Witness Test is to simulate all possible load conditions and adverse scenarios that could potentially occur during real-time operation and witness how the equipment will perform in each. Pre-testing in a lab environment enables necessary ­­­­­last minute tweaks possible at the factory and eliminates on-site troubleshooting.


Catching any shortcomings at this stage is much preferred over discovering them post-installation. Especially when employing customized peripheral equipment, a Factory Witness Test is a good check to verify correct integration between the equipment, decreasing installation time and ensuring smooth integration testing on site. 


With regards to uninterruptible power supplies, the lion’s share of our business involves engineered solutions. In this vein, we find that customers often like to do “burn ins” – meaning the equipment runs at 100% load for XXX hours straight to verify the machine’s performance over time. Harmonics, efficiency, and failure mode testing are also commonly conducted at the factory.


Our test labs are also equipped to conduct specialized testing, such as short circuit testing, 100% step load without batteries, and any complicated set-ups. In addition, our visiting customers enjoy being able to verify dimensions of the units, mounting points, and interconnections, which will diminish the hours necessitated by any unforeseen adjustments.


The value of pre-testing to ensure that no issues arise on-site is clear; all of this advanced testing will go a long way towards delivering peace of mind when delivery and installation dates are fast approaching.

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