Southwire’s Medium Voltage Switchgear and Substation Cable is a non-shielded, protected, carefully stranded cable that has no voltage rating. The cable doesn’t have UL listing and isn’t identified by the National Electrical Code (NEC). The cable’s mainly use is for installment in medium voltage switchgear, motor controllers, and substations. In regard to make use of inside enclosures and equipment, even if this cable itself is not UL listed, a UL approval can be acquired on the complete assembly by getting the system tested and approved.
The cable includes a finely stranded conductor to enable simpler installation and tight bends inside enclosures. Because the cable doesn’t have metal shield it’s easy and straightforward to terminate. There isn’t any semi-conductive insulation shield to get rid of and there’s no metallic shield to terminate. Termination is as easy as taking out the insulation to reveal the conductor and attaching the lug. The possible lack of a complex termination and the truth that the cable’s conductor is finely stranded facilitates quick and easy use and installation inside enclosures and substations.
No Standard or Approvals
Even though Southwire’s Medium Voltage Switchgear and Substation Cable doesn’t have industry approvals, the cable does meet the requirements for insulation utilized on conductors (whether rigid or flexible) within clause 126.96.36.199 of ANSI/IEEE C37.20.2-1999 and clause 188.8.131.52 of ANSI/IEEE C37.20.3-2001), which identifies the test requirements for insulating material utilized on bus bars. On top of that, the cable has gone by the fundamental Insulation Level (BIL) test that simulates a Lightning Strike with-stand of 150kV. This is actually the particular test voltage employed for BIL testing of switchgear operating at 38kV. Passing these tests shows the cables viability to be utilized within medium voltage switchgear.
No Voltage Rating
The cable doesn’t have voltage rating since the voltage a conductor can safely hold is associated with the cable’s insulation, air spacing and the dielectric strength of the insulator. The NEC offers no recommendations for cable spacing inside enclosures for insulated cables. They have printed cable spacing data for outdoor and indoor bare cables in Table 490.24.
Insulated cables, like Southwire’s Medium Voltage Switchgear and Substation Cable could be spaced closer together than a non-insulated cable. Southwire has carried out testing on this cable in managed conditions and has established spacing guidelines for installation inside medium voltage enclosures under ideal conditions. Under less than ideal circumstances where water, dirt, dust, or other contaminants can find their distance to the enclosure, cable tracking can happen and cause failure. It is quite crucial that the inside of the enclosure be kept free and clean of contaminates.