PBI Line Post Sensors

Shielded Resistive Dividers with Industry-Leading Testing

Why We Stand Out

Our shielded, non-inductive resistive divider delivers linear output voltages proportional to the primary voltage, remaining reliable over temperature, aging, proximity effect, or weather conditions; it offers robust design features, allowing low voltage AC outputs to be open-circuited or shorted without damage while preventing high voltage from impacting secondary leads. Each Piedmont Bushings and Insulators, LLC sensor undergoes rigorous testing, including partial discharge testing up to 150% of maximum operating voltage (with an insulation system specification of < 2 picocoulombs of discharge) and Hi-Pot testing, ensuring top industry standards.

FAQs

  • PBI’s sensors measure both current and voltage, the current sensor is an air wound coil that measures the magnetic field coming off the cable.  The voltage is measured using a Resistive voltage divider at 10,000:1

  • Piedmont Bushings and Insulators have been making line post sensors since 1985.

  • Our sensors are differentiated by our rigorous testing procedure.

    1. Initial Partial Discharge Test at minimum 60kV. Pass Criteria <2pC

    2. One minute hipot based on rated voltage

    3. Follow up Partial Discharge Test at minimum 60kV. Pass Criteria <2pC

    4. Thermal Cycle: Each Sensor is placed into a -40F freezer and left for 24 hours, it is then removed and left at room temperature for 6 hours, it is then placed into a 220F oven and left for 24 hours and then removed.

    5. Follow up Partial Discharge Test at minimum 60kV. Pass Criteria <2pC

    6. Second hipot test for one minute

    7. Final Partial Discharge Test at minimum 60kV. Pass Criteria <2pC

    If the sensor shows no changes in P.D. it is then serialized and released back to  assembly for final inspection and pack out.

  • We do not put connectors on the base of our sensors as standard practice.  Connectors add another point  of potential catastrophic failure for the utility.  It also adds cost and saves little time in installation.  We have been required by some utilities to include connectors but will require a waiver and accepted responsibility by the utility for this decision.  We have had experience with a major utility with this decision in the past and after several years they were seeing moisture ingress issues with the connectors that caused them problems that they ultimately replaced with non-connectored sensors at their expense. 

  • Ensure all sensors are subjected to partial discharge, hipot, and thermal cycling. These tests are vital to mitigate risks of failures in the field.

  • Capacitor Controls, Reclosers, end of line voltage for voltage manipulation programs (CVR, VVO, etc), theft detection.

    1. PBI has been manufacturing line sensors for 40 years. We have extensive experience with Dielectrics and understand what causes sensor to fail.  That’s why we spend time and money ensuring quality in manufacturing here in the US and safety with rigorous testing, protecting linemen since 1985…