Defining Pass or Fail Checks for Medium-Voltage Switchgear FAT
A buyer's guide to writing clear pass or fail criteria for factory acceptance testing of metal-clad, withdrawable medium-voltage switchgear rated 3.6–12 kV and 630–5,000 A.
Before signing off a factory acceptance test, decide which checks are binary pass or fail and which are recorded measurements. For a metal-clad enclosure with a withdrawable unit, a practical starting point is the withdrawable mechanism: does the unit rack in and out smoothly through its full travel, and do the shutters and interlocks behave as specified? Make this a pass or fail check with a defined number of operations, not a visual impression.
Build the rest of the test schedule around the rated voltage range of 3.6–12 kV and rated current range of 630–5,000 A, treating these as reference values from the catalog rather than guarantees for the supplied model. Ask the supplier which dielectric and current-related tests they propose, at what values, and what result counts as a failure. For each check, agree the instrument, the acceptance limit, and who witnesses it.
Before requesting a quote, confirm with the supplier which factory tests are standard, which are optional, what documentation and test records are provided, and how deviations are handled.