Medium Voltage Terminations

[rich000]

The seperation between live parts is 6". The switchgear is 15kV.

The bus work is factory buswork, but the terminations are made in the field.

Should the connections be insulated?

Is it a violation of Table 490.24 if it is not (based on paragraph 490.24)?

490.24 Minimum Space Separation. In field-fabricated in-
stallations, the minimum air separation between bare live con-
ductors and between such conductors and adjacent grounded
surfaces shall not be less than the values given in Table
490.24. These values shall not apply to interior portions or
exterior terminals of equipment designed, manufactured, and
tested in accordance with accepted national standards.

 

[SG-1]

Yes, tape & putty or call the factory & get some boots.

Is that VCP-W switchgear ?

In any case check the switchgear instruction booklet, you could void your warrenty.

 

[rich000]

Yes, tape & putty or call the factory & get some boots.

Is that VCP-W switchgear ?

In any case check the switchgear instruction booklet, you could void your warrenty.

Good eye! It is VCP-W. And thanks.

 

[jdsmith]

490.24 Minimum Space Separation. In field-fabricated in-
stallations, the minimum air separation between bare live con-
ductors and between such conductors and adjacent grounded
surfaces shall not be less than the values given in Table
490.24. These values shall not apply to interior portions or
exterior terminals of equipment designed, manufactured, and
tested in accordance with accepted national standards.

If this is switchgear is is built and tested to IEEE/ANSI C37.20.2 and many other standards in the C37 family. The cable termination compartment would qualify as an interior portion of equipment designed, manufactured, and tested to accepted national standards.

I think 490.24 is intended for "homebrew" terminal chambers and buswork. For example, we have some 1948 era 3000 HP motors that were originally designed for the T leads to exit the bottom of the motor and connect to the feeder cables in a pit under the motor. When we rewound the motors, we engineered a motor terminal box 4 ft wide x 7 ft high that we attached to the side of the motor and brought the six T leads into our box. 490.24 would apply to our custom motor terminal boxes because they were designed to ANSI standards but they were not tested to ANSI standards.