dup18
Electrical
- Feb 27, 2012
- 18
We have an application that we need to run about 20 feet of high voltage conductors (500 kcmil - 3 of them)in a mine substation. The cables will run from the transformer phase leads to the top of an outdoor switch house. The voltage is 12,470 volts. I cannot use a cable.
I guess that I have three choices:
a) Bare conductors - I am concerned about the spacing between conductors at one location near the switch house.
b) Insulated conductors (non shielded) - I cannot find any insulated 500 kcmil single conductor that are rated for outdoor use.
c) Insulated conductors (shielded) - My concern is what to do with the shields - ground them to the transformer neutral? or the station ground bed? or the resiatance (safety) ground bed. This is a mine location. The system is resistance grounded and must have a separate ground bed for the grounding resistor (and ground conductors within the mine supply cable). This is to provide isolation from the station ground bed so that lightning strikes to the station are not coupled into the mine distribution system and is required by mining law.
I would prefer to use non-shielded insulated conductors. Does anyone know where to obtain these with an outdoor rating? I was also thinking about applying UV resistant shrink tube to these conductors. Has anyone ever done this?
These will be elevated so there is no danger of human contact and these conductors will be installed on standoff insulators regardless of the type of conductor that is used.
Regards,
Dave
I guess that I have three choices:
a) Bare conductors - I am concerned about the spacing between conductors at one location near the switch house.
b) Insulated conductors (non shielded) - I cannot find any insulated 500 kcmil single conductor that are rated for outdoor use.
c) Insulated conductors (shielded) - My concern is what to do with the shields - ground them to the transformer neutral? or the station ground bed? or the resiatance (safety) ground bed. This is a mine location. The system is resistance grounded and must have a separate ground bed for the grounding resistor (and ground conductors within the mine supply cable). This is to provide isolation from the station ground bed so that lightning strikes to the station are not coupled into the mine distribution system and is required by mining law.
I would prefer to use non-shielded insulated conductors. Does anyone know where to obtain these with an outdoor rating? I was also thinking about applying UV resistant shrink tube to these conductors. Has anyone ever done this?
These will be elevated so there is no danger of human contact and these conductors will be installed on standoff insulators regardless of the type of conductor that is used.
Regards,
Dave
