7/28/2019 Disconnector Fundamentals

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Photographs show the

pressure relief capabilityof the PDV/PVR family of

surge arresters. Notice in

the “after” photo the

PDV/PVR disconnector

has successfully oper-

ated isolating the

arrester from the system.

This allows the line to be

put back in service and

the arrester replaced at a

more convenient time.

Ohio Brass PDV (distribution) and PVR (riser pole) arresters are normally furnished with a disconnector (also called an isolator). The disconnector isincorporated within the housing of the insulating base bracket at the bottomstud area. All Ohio Brass arresters furnished with the finned insulating base

PDV/PVR DISCONNECTOR 

FUNDAMENTALS

TIME-CURRENT CHARACTERISTICS OF DISCONNECTORS PDV / PVR

■

bracket include the ground lead disconnector.

The disconnector performs a vital service when a rare arrester failure occurs. Subsequent toarrester failure, the disconnector reacts to a rapid increase in 60 cycle current flow throughthe arrester. Voltage develops across a resistor in the disconnector assembly allowing it tosparkover a small gap. This causes the arc to terminate on a cartridge. As the cartridgedetonates, it separates the ground lead from the failed arrester. As the circuit is broken,

system lockout is prevented. If a shorted arrester would remain connected to the line, then it would not be possible to re-energize the line.

The disconnector also serves as a time saving visual aid in identifying the failed arrester fromreplacment.

 Arresters in service are continuously energized with 60 Hz voltage. The disconnector mustnot operate under normal service conditions. Standards require the arrester to be tested withthe disconnector installed thus requiring the discharge operation characteristics to beverified. Examples of tests performed with the disconnector installed are duty cycle, highcurrent, low current-long duration and contamination.

The time for operation of the disconnector is verified by subjecting the sample to be testedto rms currents ranging from 20 through 800 Amps. The time for the disconnector tooperate is plotted as a function of current magnitude. The time current curve for our PDV/PVR arrester is shown when tested per ANSI/IEEE C62.11-1993 tests.

♦ A RRESTERS ♦

 © Copyright 2004 Hubbell • 210 North Allen Street • Centralia, MO 65240

NOTE: Because Hubbell has a

policy of continuous product

improvement, we reserve the

right to change design and

specifications without notice.

 ® 

POWER

SYSTEMS, INC.

EU1487WB

TiPS NEWSView from Vol. 3No. 1 JAN 1997

&

573-682-5521 Fax 573-682-8714 http://www.hubbellpowersystems.com