Substation Acceptance Testing

New equipment is not necessarily correct equipment. Transformers arrive from the factory with winding connections reversed, bushings misinstalled, or tap changers that don't advance through all positions. Circuit breakers come off the truck with contact gaps out of tolerance or trip coils that won't pull in at minimum voltage. Protective relays get wired with polarity errors that will pass a visual check and fail the moment a fault occurs. Acceptance testing catches these problems before the equipment is energized and before they become outages, warranty disputes, or incident reports.

We run NETA ATS-aligned acceptance test suites on new and replacement substation equipment for utilities, electric cooperatives, industrial plants, and EPC contractors commissioning new substations across Florida and the Southeast. Every job ends with a full documented report: raw test data, calibrated instrument records, anomaly findings with severity classification, and a recommended-action list the asset owner can act on before energization.

Southern Switch performs this acceptance testing in-house, using our own technicians and Doble instruments, to the applicable NETA ATS and IEEE criteria listed below. This is Southern Switch field testing, not NETA-accredited testing. When a project specification specifically requires NETA-accredited testing, we coordinate that scope through our partner Sigma C Power Services.

What acceptance testing is designed to catch

The three failure categories acceptance testing addresses are factory defects, shipping and installation damage, and integration errors. Factory defects include insulation voids, incorrect winding ratios, and tap changer contacts that fail the contact-resistance limits before the unit ever sees load. Shipping and installation damage includes cracked bushings, contaminated oil from a broken breather or improperly sealed conservator, and mechanical damage to operating mechanisms that is not obvious on visual inspection. Integration errors are the most common: protection relay settings that don't match the coordination study, CT polarity reversals, and control wiring mistakes that mean the protection system will misoperate or fail to operate under fault conditions.

None of these are theoretical. They show up regularly on new equipment at new sites. The question is whether they are found during acceptance testing, when correction is straightforward, or during the first fault event, when the cost is exponentially higher.

Solar and renewable substation commissioning

Solar interconnection agreements and EPC commissioning scopes commonly require acceptance testing to NETA ATS before a collector substation can energize and begin delivering power to the grid. We work directly with utilities managing their solar generation assets and with EPC contractors who need a substation testing subcontractor to complete the commissioning scope. We are ISNetworld and Avetta approved, which clears most utility and IPP vendor qualification requirements without a separate qualification process.