5.1 General - The CVT shall be a single bushing type suitable for mounting on a flat horizontal surface. The bushing shall conform to applicable ANSI standards. The bushing shall be high altitude type, if necessary for the altitude of application of the CVT as specified in Section 2 of this Specification. Porcelain used in the bushing shall be manufactured by the wet process and shall be homogeneous, free from laminations, cavities, or other flaws affecting its mechanical strength or dielectric quality. The glazing of the porcelain shall be free of imperfections, such as blisters or burns. The bushing shall be colored ANSI-70 gray. 5.2 Line Terminal - The unit shall be furnished with a standard NEMA four (4) hole tinned pad, compatible with aluminum or copper terminal connectors. 5.3 Grounding - The base of the CVT shall be supplied with a clamp-type ground terminal capable of handling 2/0 to 4/0 AWG stranded copper cable. An external hook-stick lever shall be supplied for operation of the supplied CVT voltage ground switch. 5.4 Base - The base shall be aluminum or another corrosion-resistant material like stainless steel. 5.5 The CVT shall be equipped with 1¼” knockouts and conduit fittings for customer's rigid conduit for secondary wiring. 5.6 An AC strip heater shall be supplied for the base housing if air insulated. 5.7 The secondary winding shall be fused at 20 amps. 5.8 A spark gap shall be provided for lightning protection. 5.9 Corona rings shall be furnished for nominal voltages of 230kV and above. 5.10 The complete installation RIV level (including electrical and mechanical hardware) shall not exceed 250 microvolts and shall be free from all visible corona.
