Turner Stategic Technologies | Electrical
Joint Base Lewis-McChord’s distribution system is a single-point-grounded system operating at 13,800 volts. Joint Base Lewis-McChord has adopted Tacoma Public Utilities (TPU) design criteria as “industry standards” for utility construction.
- $1.2MM contract
- Hundreds of Housing Units Serviced
- 165- New Guy Poles
- 244-Cross Arms
- 65- Pole Mount Trans
- 608- Insulators
- 66,396′ FT- ACSR Bare Wire Primary
- 37, 742′ FT- TRIPLEX Secondary w/full size ACSR messenger
- 13, 100′ FT- Solid Wire
General Overhead construction requirements:
- All new construction shall be underground unless dictated otherwise by special circumstance.
- Pole-mounted three-phase transformer banks shall be no larger than 3-75KVA. Pole- mounted single-phase transformers shall be no larger than 100KVA.
- Pole-mounted transformers shall have separate ground for lightning arrestors, case grounds, and neutral conductor. (Neutral ground is isolated per NESC.)
- Construction shall be Grade B per the National Electrical Safety Code (NESC), ANSI C2.
- Size, sag, and support overhead conductors per NESC and TPU standards.
- Lightning arresters, appropriately sized, shall be provided at all risers, dead-end poles, and at each overhead and pad-mounted transformer. All cross-arms shall be 9 foot in
- length unless application requires longer/larger arms.
- Primary risers shall be constructed using alley-arm construction with arms parallel to main line
- Splices and dead-ends shall be of the automatic type. Deadends shall be polymer-type.
- Stirrups and other connections shall be made using compression type connectors listed for the application.
- Fused disconnects shall be of the loadbreak type.
- Power poles shall be rated Class 2.
- Secondary conductor connections shall be made using compression-type connectors.