Acceptance testing
Testing performed on new equipment or installations to establish condition, verify installation, and support readiness for service against the applicable plan, specifications, and criteria.
Maintenance testing
Periodic testing used to evaluate equipment condition, identify deterioration, support maintenance decisions, and help determine continued serviceability.
Commissioning
A coordinated process for verifying equipment, systems, controls, documentation, and functional performance before turnover or energization.
Apparatus testing
Testing focused on primary power equipment such as transformers, circuit breakers, cables, switchgear, instrument transformers, grounding systems, and rotating machinery.
Relay and P&C
Protection and control work focuses on protective relays, CT and PT circuits, DC control power, logic, communications, trip paths, event records, and the schemes that detect and isolate abnormal conditions.
Primary and secondary injection
Primary injection drives current through the primary power path to evaluate equipment and the connected protection chain. Secondary injection applies test quantities directly to relay or meter inputs to verify measurement, logic, timing, and outputs.
TTR, DLRO, and insulation resistance
Transformer turns ratio testing compares winding ratios and phase relationships. A digital low-resistance ohmmeter measures very small resistance values using a four-wire method. Insulation resistance testing applies DC voltage to assess the resistance of insulation systems.
Test before touch
A safety principle that requires absence of voltage to be verified with an adequately rated test instrument using the established procedure before equipment is treated as de-energized. Always follow employer procedures and qualified-person requirements.