Skyline College
Bid No. 86513

Building 8 Swing Space Revisions

 

Section 16450           GROUNDING

Part 1           GENERAL

1.01.                      Description of Work:

A.                  The work of this section consists of furnishing, installing, connection and testing of all grounding systems as specified herein and as shown on the Drawings.

1.02.                      Related Work:

A.                  See the following specification sections for work related to work in this section.

1.                   16120         Low Voltage Wire and Cable

1.03.                      Standards and Codes:

A.                  Work and material shall be in compliance with and according to the requirements of the latest revision of the following standards and codes.

1.                   California Electrical Code (CEC).

a.                   250 Grounding.

2.                   American Society for Testing and Materials (ASTM) Publication:

a.                   B8 Standard Specification for Concentric-Lay-Stranded Copper Conductors, Hard, Medium-Hard, or Soft.

b.                   B228 Standard Specification for Concentric-Lay-Stranded Copper-Clad Steel Conductors.

3.                   Institute of Electrical and Electronics Engineers (IEEE).

a.                   81 Guide for Safety in AC Substation Grounding.

1.04.                      Submittals: 

A.                  As specified in Division 1 and Section 16010.

B.                  Catalog Data: Provide manufacturer’s descriptive literature.

C.                  Single Submittal: A single complete submittal is required for all products covered by this Section.

1.05.                      Quality Assurance:

A.                  Each and every concealed connection must be inspected by the Owner's Representative before it is covered up by the Contractor.

Part 2           PRODUCTS

2.01.                      General:

A.                  The grounding system shall consist of the grounding conductors, ground bus, ground fittings and clamps, and bonding conductors as shown on the Drawings.

2.02.                      System Components:

A.                  Ground Conductors: Buried conductors shall be medium-hard drawn bare copper; other conductors shall be soft drawn copper.  Sizes over No. 6 AWG shall be stranded conforming to ASTM B8.

B.                  Ground Connections: Exposed ground connections shall be high copper alloy bolted pressure types or exothermically welded type, as noted.  Embedded or buried connections, taps, and splices shall be either exothermically welded type or approved compression types for connection of copper to copper or copper to steel, as required.  Connections of grounding conductors to equipment ground buses and metal enclosures shall be of the binding post type with a 1/2-13NC stud.  Each post shall accommodate cables from #4 AWG to #2/0 AWG.

C.                  Ground Bus: 2” x 1/4” x 24” copper busbar.  Provide isolation stand off bushings.  Provide drilled and tapped 3/8” diameter holes in two offsetting rows 1” apart and 2” on center.  Provide “ALCU” lugs and bronze bolts.  Connect busbar to main grounding system and bond to metallic domestic cold water pipe with #8 ground conductor.

Part 3           EXECUTION

3.01.                      Installation:

A.                  Ground all equipment for which a ground connection is required per CEC Article 250, even though not specifically shown on the Drawings.

B.                  Make connections of grounding conductors to equipment ground buses and enclosures using binding post type connectors.

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