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Electrical Devices & Components

As a normal course of installing substations and upgrading/modifying electrical systems, many components require testing. The following is a brief outline of tests that are commonly performed by PTS on various devices and components.

(Click navigation button at the left for more details or sample PTS datasheet.)


Current Transformers (CTs): Ratio, Polarity, Tap-progression, Insulation Resistance, and Saturation.


Potential Transformers (PTs): Ratio, Polarity, and Insulation Resistance.


Power Cables: dc High-Potential tests (plot: Current-vs-Voltage, Current-vs-Time, and Discharge), Shield Continuity, and Insulation Resistance.


Ground Grid: Four-Probe test (plot: Impedance-vs-Distance) to demonstrate earth/soil (ground) resistance.


Circuit Breakers:

     Low Voltage - Trip-Unit (Current Injection), Contact Resistance, and Insulation Resistance.

     Medium Voltage - Trip/Close Ckt, Protective Relay, Contact Resistance, High-Pot, and Insulation Resist.

     High Voltage - Travel Test, Power-Factor (Doble), Contact Resistance, Anti-Pump, Aux Controls, etc.


     Air - Contact alignment, Resistance, Inspections (Main Contacts, Arc Contacts, Arc Chutes), etc.

     Vacuum - Interrupter Integrity, High-Potential, Resistance, Wipe/Swipe/Erosion, etc.

     Gas (SF6) - Aux Controls, Contact Resistance, Power Factor (Doble), Travel/Timing, etc.


Disconnect Switches: Blade Alignment, Contact Resistance, Insulation Resistance, and Op. Mechanism


Power Transformers: Turns-Ratio, Insulation Resistance (and Polarization Index), DC Resistance, Low Voltage Excitation, AC Impedance, LTC checks, Paralleling Circuits, Sudden-Pressure (Rapid-Rise) Relay, Bushing Potential Device, Current Transformers, Alarms, Fans/Pumps/Aux-Power Controls, Temperature/Level Gauges, and Power Factor (Doble) Bushings.



Comprehensive Tests: Comprehensive testing proves certain aspects of multiple device interactions relating to their specific functions. These tests can be very complex and are detailed on their own page; click appropriate navigation button on the left: Switchgear, Control Circuits, and Primary Injection.


 In addition to those listed, PTS has the expertise and capability to perform other (less common) tests, as desired by some customers

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