12U301 3Ø UG Switching Vault
Revision 7
Feb 24, 2021
Notes:
- Ground plates are preferred for grounding during new vault installations. Ground plates must be installed a minimum 5' deep. Cover ground plates with tamped select backfill. If vault is to be backfilled with sand or gravel, bury plates below select backfill first or install two 5/8" x 8' ground rods. When grounding vaults which are already set and backfilled, install two 5/8" x 8' ground rods. See N0304 for double ground rod installation.
- Run #2 Cu ground bus continuously from ground plate to ground plate, into the vault and around the interior of the vault. Run the ground bus through the two vise type equipment ground connectors on the bottom flange of each J-box bracket. Form the ground bus into a U-shape (horse shoe) under each J-box to accommodate connection of the cable concentric neutrals and load-break deadend cap drain wires. Complete the ground loop by connecting the ground wire to itself.
- Train primary cables similar to the configuration shown to facilitate ease of switching and elbow replacement. Cables should enter the vault so that all of the cables will lay in the same direction. A rule-of-thumb is to train each cable entering the vault so that it touches a minimum of three walls, including the wall at which it terminates on a J-box.
- Bond the drain wires on the load-break deadend caps (Compatible Unit T1701) to the #2 Cu ground bus.
- Load-break Elbow Variable Compatible Unit - Specify T1103 for #2 AWG cable and T1105 for 1/0 AWG cable.
- 4'8x7' vaults (see V0207) are the preferred installation option. 4'8x4'8 vaults (see V0203) may be used as an alternate for limited space applications. See the appropriate compatible pages for cover options.
| Compatible Unit | Description | Qty |
|---|---|---|
| N0302 | Double Ground Plate System | 1 |
| R0185 | Nut, Unistrut Self-Hold 1/2"-13 UNC | 1 |
| T110# | Elbow, Load-break Kit 200A 15kV w/ Sealing Slv | 6 |
| T1603 | 4-Position 200A Load-Break | 3 |
| T1701 | Cap, Deadend Load-break Underground 200A 15kV | 6 |
| V0207 | Vault, Concrete 4'8"W x 7'L x 4'H & Cover, Vault 4'8"W x 7'L x 12"H w/ (2) 3'W x 3'L Diamond Plates | 1 |
| Z0304 | Clamp, Equipment Grounding #6 Sol-1/0 Str Cu | 7 |
| Z0702 | Connector, C-Crimp Cu #2 to #8-#4 | 6 |
| Z0703 | Connector, C-Crimp Cu #2 to #2 | 7 |