E29.REV

HEADER DUCT SYSTEM

NOTE: FINAL DATE: JUNE, 1988.

NOTE: HEADER DUCT: MINIMUM 2-3/8 INCH OVERALL HEIGHT WITH 2-1/2 INCH FILL OVER CELLS

Part 1 -	GENERAL

1)	WORK INCLUDED

A.	Work in this Section includes the providing of labor, materials, equipment and services necessary for a complete and safe installation in accordance with the contract documents and all applicable codes and authorities having jurisdiction for the following:

1.	Metal header duct shall feed:

a.	Cellular steel floor similar to-----.

b.	Composite structural floor similar to -----.

c.	Sectional steel cells similar to -----.

2.	Provide separate duct for 120 volt wired service, telephone raceway service, signal raceway service and signal wired service.

3.	Metal header duct shall be suitable for installation in:

a.	----- inch floor fill.

b.	----- inch of available structural slab.

2)	RELATED WORK AND REQUIREMENTS

A.	Requirements of GENERAL CONDITIONS, DIVISION No. 1 and Section GENERAL PROVISIONS FOR ELECTRICAL WORK apply to all work in this Section.

NOTE: EDIT TO SUIT PROJECT REQUIREMENTS. INCLUDE ONLY SECTIONS DIRECTLY AFFECTING WORK OF THIS SECION

B.	Related work in the following Sections:

1.	RACEWAYS.

2.	WIRE AND CABLE.

3.	LOW VOLTAGE CIRCUIT BREAKER SWITCHGEAR.

4.	GROUNDING SYSTEM.

5.	DEVICES.

6.	UNDERFLOOR DUCT SYSTEM.

7.	TRENCH HEADER SYSTEM.

8.	-----.

3)	REFERENCE STANDARDS

A.	Published Specifications' standards, tests or recommended methods of trade, industry or governmental organizations apply to work in this Section.

B.	Comply with all applicable national, state and local codes and refer to Section GENERAL PROVISIONS FOR ELECTRICAL WORK for additional Reference Standards.

4)	QUALITY ASSURANCE

A.	Refer to Section GENERAL PROVISIONS FOR ELECTRICAL WORK for Guarantee and other Quality Assurance requirements.

5)	SUBMITTALS

A.	Submit shop drawings including dimensioned layout on architectural background drawings and catalog cuts.

B.	Submit samples for fittings.

Part 2 -	PRODUCTS

1)	BASE BID MANUFACTURERS

A.	Robertson, Walker Brothers, Square D and Granco.

2)	HEADER DUCTS

A.	Provide corrosion resistant header ducts with a minimum of 8.5 square inches cross sectional area and constructed of No. 14 gauge steel for sides, top and bottom.

3)	ACCESS UNITS

A.	Header-to-cell:

1.	Provide approximately 6 inch diameter with 4-3/4 inch diameter opening to header and provisions for leveling and adjusting without cover removal.

NOTE: CONFIRM IF SUFFICIENT, WITH STRUCTURAL ENGINEER. SLABS CAN DEFLECT BEYOND 3/4 INCH LIMIT

2.	The range of vertical adjustment shall be 2-1/2 inches to 3-1/4 inches from top of cells.

3.	Provide gasketed covers and cover adaptor to receive floor covering or finish. Locate at header-to-cell access locations.

B.	Header-to-header shall be similar to access units, except openings shall be approximately 7-1/4 inches diameter to header and 12 inch x 3 inch oblong to cell.

C.	Provide metal wireway connectors from ducts to power panels and from ducts to 6 inches above finished floor for the telephone and signal terminations.

4)	GROMMETS

A.	Provide 3 inch diameter with 1/4 inch radius pulling edge for 120 volts.

B.	Provide 3 inch x 6 inch with 1/4 inch radius pulling edge for telephone and signal.

C.	Die press or roll into position at header-to-cell access openings. Snap-in type will not be acceptable.

NOTE: - DELETE IF NOT APPLICABLE.

5)	CAPPED OPENING ASSEMBLIES

A.	Provide blanking cap with concrete retaining tabs suitable for receiving future access units.

6)	FITTINGS

A.	Provide cast aluminum fittings.

B.	Provide stamped aluminum fittings.

NOTE: CHECK CLIENT AND DETAIL ON DRAWING.

C.	Provide floor surface mounted fittings.

NOTE: CHECK CLIENT AND DETAIL ON DRAWING.

D.	Provide floor recessed mounted fittings.

E.	Shape and finish shall be as approved.

NOTE: FILL IN NO. OF OUTLETS REQUIRED. CONSIDER PROVISIONS FOR AFTERSETS

F.	Provide ----- high tension outlets with horizontally mounted, grounded duplex convenience receptacle.

NOTE: FOR 20 AMP BRANCH CIRCUITS.

1.	Receptacle shall be 20 amp similar to Hubbell No. 5362.

NOTE: FOR 15 AMP BRANCH CIRCUITS.

2.	Receptacles shall be 15 amp similar to Hubbell No. 5252.

3.	Locate outlets and provide a maximum 6 outlets per branch circuit.

NOTE: FILL IN NO. OF OUTLETS REQUIRED. CONSIDER PROVISIONS FOR AFTERSETS

G.	Provide ----- low tension outlets with single bushed opening of a size approved by the telephone company and locate outlets as directed.

7)	MARKERS

A.	Provide markers as follows:

1.	Screwdriver slotted brass shall be for high tension cells.

2.	Screwdriver slotted Monel metal shall be for telephone cells.

3.	Phillips head slotted Monel metal shall be for signal cells.

4.	Marker locations shall be at ends of duct runs.

8)	EXPANSION FITTINGS

A.	Provide expansion fittings when crossing expansion joints.

9)	ACCESSORIES

A.	Provide accessories as required.

Part 3 -	EXECUTION

1)	INSTALLATION

A.	Inspect cells for alignment and cleanliness and report cell non-alignment for correction.

B.	Remove foreign matter from cells.

NOTE: CHECK STRUCTURAL ENGINEER BEFORE SELECTING ONE OF THE FOLLOWING

C.	Cell joint cover plates will be supplied and temporarily installed under General Construction Work and under Electrical Work, cell joint cover plates shall be permanently installed.

1.	Apply asphaltic compound to bottom edges and secure with a minimum of 2 screws per valley at ends and a maximum 18 inches on centers.

NOTE: FOR COMPOSITE FLOOR, ADVISE STRUCTURAL ENGINEER TO PROVIDE COVER PLATES WITH PRESET INSERTS IF OUTLETS ARE REQUIRED AT CELL JOINTS. PRESET INSERTS SHOULD BE FLARED AT BOTTOM, SHOULD BE 2 INCH IPS AT TOP AND EXTEND TO 1/8 INCH BELOW FINISHED CONCRETE FLOOR

D.	Seal cell joints:

1.	Apply asphaltic compound to ends of cells, jute tape and apply second overall coat of compound.

2.	Apply waterproof, self-adhesive polyethylene tape.

E.	Install duct immediately prior to concrete pour.

F.	Locate boxes and lateral duct runs clear of partitions and module lines.

G.	Duct spacing shall be as noted.

H.	Duct elevation shall be ----- inches below finished floor.

I.	Set and level to concrete screed point, top of access units, capped opening assemblies and header-to-header junction boxes.

J.	Close duct and box openings with closure plates.

K.	Secure headers to cells with anchor straps or tack weld both sides 5 ft. on centers.

L.	Secure header-to-header junction boxes to header duct and encase in cement mortar.

M.	Seal joints.

N.	After concrete sets, adjust tops of access units, assemblies, and boxes flush with top of concrete floor and grout.

O.	Before installing wire, clean all headers.

P.	Cut and drill through concrete and cell for Electrical Work.

Q.	Tap floor and locate outlets after concrete and floor covering is in place.