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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Additional diagnostic tests, such as leakage current measurements that measure the extent of insulation losses, are recommended. CAUTION The ieee consequences of a cable system insulation failure during any high-voltage test should be considered prior to undertaking isee such test. The values in Table 4 to Table 7 were derived from empirical cumulative distribution functions CDF for the data consisting of data points obtained for aged cable systems, mainly in utilities from North America, i.
While other wave shapes are available for testing of cable systems, recommended test voltage levels have not been established. These are not the only levels that a user may select; for example 75th and 90th percentiles may be equally valid iee the choice is often guided by the remediation and risk strategies of the 400.2. Nor is IEEE undertaking to perform any duty owed by any other person or entity to another.
A comparison of results between different phases of the same segment or sequential section will help identify if this is the case.
VLF cable testing – Wikiwand
Dielectric losses can be affected by insulation material parameters such as different materials and the cross-linking by-products, although in older cables the concentration of the latter will be negligible. If this connection is missing or deteriorated, it must be replaced at this time.
More importantly, it must be understood that, for different insulations, installations, and cable types, tangent delta, differential tangent delta and tangent delta stability figures of merit can vary significantly from each other. This Guide is one part of a series of guides that discuss known diagnostic techniques for performing electrical tests in the field on shielded power cable systems.
Also included are tables giving limits of the temporal stability of tangent delta, differential tangent delta difference in tangent delta at two test voltagesand absolute values iieee tangent delta for new and service-aged cable systems. NOTE 4—As this test technique measures the average of all the insulations under test, supplemental testing is recommended to measure individual sections of the insulation. 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.
However, there is a trade-off between gathering additional information about the cable under test and going to elevated voltage levels, with the associated higher risk that the cable may fail as the voltage is increased. Log In Sign Up. If PDs occur, the voltage is maintained for an additional 30 s to 60 s and then ieew reduced until the PDs extinguish.
As more data are acquired, the values may change and these changes will be introduced in future editions of this guide. The values given in the tables may change as additional data are accumulated. If a failure occurs during the test, the test voltage collapses. Grounding connections that can be securely tightened are recommended. Diagnostic tests can be non-destructive if they are performed at voltages at or below the normal operating voltage.
Regarding the test times: The voltage can either be kept at this level or raised to the withstand level for 20 s to 50 s 2 cycles to 5 cycles where the PD activity is measured before being slowly reduced until the PD extinguish.
A typical waveform is shown in Figure B. Generally, the measured loss is increased under this circumstance; however, the precise impact on the loss is not clear. All exposed conductive parts of the test system must be bonded to the common ground point.
In withstand testing, Gnerlich [B11]the test object must survive a specified voltage applied across the insulation for a specified period of time without breakdown of the insulation Hampton, et al. Patents Attention is called to the possibility that implementation of this standard may require use of subject matter covered by patent rights.
A cable in which an insulated conductor is enclosed in a conducting envelope. Negative slope loss decreasing with Isolated loss regions such as lossy accessories or heavily water length treed regions within a large proportion of low loss cable 5. The described method is based on the application of 4000.2 pure, sinusoidal 0.
These tests are described in 5. Typical defects for fluid-impregnated and extruded cable systems are listed in Annex C.
The maximum withstand value may also be used as a final step. If a cable or cable system fails the test, the test voltage collapses.
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Could be local variations between lengths Positive slope loss increasing with Corrosion of the metallic shield or poor contact between the length metallic shield and the insulation shield. The measurement of the test voltage should be made with an approved measuring system as described in IEC The actual iewe for space charge trapping will be related to the degree and nature of the degradation. Statistical comparisons of many results increase the security of criteria levels established.
Table 4 to Table ieew show historical figures of merit see also Annex E that could be used for condition assessment for aged PE-based e.