nVent ERICO, manufacturers of the CADWELD® range of exothermic welding equipment, recently carried out some fusing tests on their CADWELD connections at their HV laboratory in Solon, USA.
In the tests, 10kA is applied until either the conductor or the CADWELD connection fails. To pass the test, the conductor must fail (melt) before the CADWELD connection does, proving that connections made using the CADWELD system are not the weak point of a grounding system.
GRC-182Q Fusing Test (cable to ground rod connections)
Conductors Used: nVent ERICO Cadweld connecting 3/4″ (19mm) ground rod to 4/0 (107mm) copper conductor.
Test Parameters: 10100A RMS 60Hz applied until fusing
Pass/Fail Criteria: The grounding connector shall not crack, break, or melt when subject to the test current.
SSC-2Q Fusing Test (cable to cable connection)
Conductors Used: 4/0 copper conductor to 4/0 copper conductor with nVent ERICO Cadweld
Test Parameters: 10100A RMS 60Hz applied until fusing
Pass/Fail Criteria: The grounding connector shall not crack, break, or melt when subject to the test current.
nVent ERICO also carried out some short-circuit current tests on their tinned copper braid (MBJ) product, in accordance with standard UL467 (Ground and Bonding). In this test 5.9kA is applied for 6.1 seconds. To pass the test, the braid must not fuse (melt) and still be able to carry current afterwards.
MBJ-50-500-10 Fusing Test (50mm2 tinned copper braid bond)
Conductors Used: 556980 (MBJ 50 – 500 – 10) tinned copper earth braid (MBJ) 50mm2, 500mm length, 6mm hole.
Test Parameters: 5960A RMS 60Hz applied for 6.1 seconds
Pass/Fail Criteria:
7.5.1 – A grounding or bonding device shall not crack, break, or melt when subject to the current and time specified in the Test Perameters.
7.5.2 – After having carried the current specified in Clause 7.5.1, continuity shall be maintained on the test sample assembly.
ETS are the authorised UK stockist and reseller of nVent ERICO Cadweld exothermic welding equipment and can also provide a comprehensive on-site CADWELD PLUS training course, carried out by a fully qualified ETS operative on behalf of nVent ERICO.
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