IEEE Std ™ I. EEE Standards. TM. IEEE Guide for Field Testing of Shielded Power. Cable Systems Using Very Low. “IEEE Guide for Field Testing and Evaluation of the Insulation of Shielded Power IEEE “Guide for Testing of Shielded Power Cable Systems using Very. Guided IEEE Series (Bundle) Standards IEEE – • IEEE Guide for Field Testing of Shielded Power Cable Systems Using Very.
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For purposes here, the term also encompasses ethylene propylene diene monomer rubber EPDM.
VLF cable testing – Wikiwand
In addition, should a failure occur under test, the resultant fault current and collateral damage to the cable and surrounding assets may be limited. The criteria used for the historical figures of merit provided in this document have been selected using the estimate of the 80th and 95th percentiles, not the lower confidence limits. This may not be the case should the cable fail under operating conditions.
However, the time to failure will vary according to the type of insulation such as PE, paper, and rubber. No part of this publication may be reproduced in any form, in an electronic retrieval system or otherwise, without the prior written permission of the publisher. The loss currents at frequencies below 1 Hz are sensitive to degradation due to water trees in extruded XLPE cables. Corrosion of the metallic shield can limit the sensitivity of PD tests due to the attenuation of high frequency signals.
Diagnostic tests can be non-destructive if they are performed at voltages at or below the normal operating voltage. However, care should be exercised to make sure that unreasonably low or high values are not selected, e.
The cable is then grounded. Sufficient information is required to determine the desired percentiles selected for the critical levels. These results may also be used to trigger further testing. Any person utilizing any IEEE Standards document, should rely upon his or her own independent judgment in the exercise of reasonable care in any given circumstances or, as appropriate, seek the advice of a competent professional in determining the appropriateness of a given IEEE standard.
The consideration of various VLF ac voltage testing methods should be based upon the following guidelines as tabulated in Table 1. The mechanisms for the increase or decrease in tangent delta are not fully understood at this time, but the greater the change in tangent delta the more severe is the insulation aging.
Many users will find isee ranges provided in 4002. H. Letters of Assurance may indicate whether the Submitter is willing or unwilling to grant licenses under patent rights without compensation or under reasonable rates, with reasonable terms and conditions that are demonstrably free of any unfair discrimination to applicants desiring to obtain such licenses.
A field test made after cable system installation, including iee and joints, but before the cable system is placed in normal service.
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The metallic shield of the cable to be tested is connected to system ground. Some tested cable systems, which were already known to have questionable due to age or failures in service service performance, were monitored for a number of years to determine their service performance.
Typical defects for fluid-impregnated and extruded cable systems are listed in Annex C. Furthermore, the viewpoint expressed at the time a standard is approved and issued is subject to change brought about through developments in the state of the art and comments received from users of the standard.
A dc test set forms the high-voltage source and a dc-to-ac converter changes the dc voltage to the VLF ac test signal. Inception of an electrical ieeee and channel growth time are functions of several factors including test voltage, source frequency and amplitude, and the geometry of the defect. All exposed conductive parts of the test system must be bonded to the common ground point. The measurement of the test voltage should be made with an approved and calibrated measuring system as described in IEC The intervals will be correspondingly longer at lower frequencies.
When the cable or cable system passes the VLF voltage test, the test voltage is regulated to zero and cable and test set are discharged and grounded. NOTE 2—PDs are detectable only if there are one or more active electrical trees or tracking sites or there are gas-filled voids in the cable 4002. or accessories.
However, if withstand tests at frequencies below 0. If no PDs are observed up to the withstand voltage, the voltage is maintained at this level for a maximum of 30 min unless PDs occur. After the initiation of PDs PDIVan electrical tree may form that can develop into a breakdown channel within minutes. The most commonly used, commercially available, VLF test frequency is 0.
Therefore, both the loss and capacitive currents can be plotted separately as a function of voltage and frequency. Enter the email address you signed iefe with and we’ll email you a reset link.