IEEE 837:2014 pdf free download – IEEE Standard for Qualifying Permanent Connections Used in Substation Grounding
4.Qualification tests
For qualification test sequence, refer to Annex D.Qualifications tests shall be performed for each family ofconnections,for example: (cable to cable straight connection, tap connection,cross connection),(cable toground rod connection), (cable to lug connection), and(cable to structure connection).
Qualification tests shall be performed for each style of connection. For example, crimped lug connectionsand lugs using bolted pressure plates to secure the cable are considered different styles. Therefore, bothconnectors are required to be tested to qualify the styles. Other examples of different connector designstyles include cable to cable and cable-cross design styles. Within a family of connectors,more robustconnectors need not be tested.For example, bolted pressure plate lugs using four (4) bolts need not betested if two (2) bolts lugs have been tested successfully for the same size. Similarly, for a family ofconnectors tested for 4/0 AWG Copper or 19/#8 Copper Clad Steel (at 90% of fusing test current for theEMF test); smaller sizes may be qualified by passing only the initial resistance tests from 5.3.2.1.For thesesmaller sizes, no other tests are required.However, connections for larger conductors specified in footnoteb of Table 3 shall be tested for each size connection.
When a connector design allows for a range of conductors, each of the tests outlined in Table 1 andAnnex D must be performed on the“largest to largest”combination as well as the“largest to smallest” combination. Connectors shall be tested for all materials for whioch they are intended to be qualified per thisstandard.For example copper-clad steel conductors and connectors that are designed to be used on copper-bonded steel ground rods must be qualified by all of the tests in this standard. Several test parameters forconnectors for use on 40% copper-clad steel conductors and copper-bonded steel ground rods are basedupon electrical equivalency of copper conductors as listed in Table 5. The test parameters for conductorsand ground rods not listed in Table 3 shall be calculated as per Annex C.
A listing of the tests to be performed for all types of connections is given in Table 1.The connections shallbe tested individually and sequentially， as shown in Table 1. If during the testing, one of the four testsamples fails, the testing must be discontinued. A group of four new samples from a different lot can thenbe retested. If one of the samples from the new group fails，the connector design does not meet therequirements of this standard and is considered as failed. This is applicable to all of the tests detailed inTable 1.
5.3.2.3 Resistance measurements
Resistance measurements shall be made when the conductor temperature is at ambient temperature. Themeasurements shall be made across the control conductor and across each connection between potentialpoints located in the center of the equalizers adjacent to the connection or at the equivalent points on a solidconductor. For thcse mcasurcmcnts, a current of a sufficiently low magnitude shall be used to avoid appre-ciable heating.
Resistance mcasurements shall be taken prior to each test within a sequential test group.For sequential testsamples, final resistance measurements shall be taken after the fault-current test in Clause 11.
5.3.2.4 Temperature correction
Ambient temperature shall be recorded concurrently with each set of resistance measurements，and theresistance shall be corrected to 20 °C.The corrected resistance shall be used in evaluating the performanceof the connection.
5.3.3 Fault-current criteria
Connections tested in accordance with Clause 1l shall not melt, separate from, or move in relation to thepre-marked conductor and must meet the resistance criteria set in 5.3.2.2.The conductor shall not fusewithin 50 mm of either end of a connection under test.