SECTION 16860

ELECTRIC DUCT HEATER

PART 1 GENERAL

SECTION INCLUDES

Electric duct heater.

Thermostats and accessories.

RELATED SECTIONS

Section 15890 - Ductwork.

SUBMITTALS

Submit under provisions of Section [01300.] [_____.]

Product Data: Provide unit size, finish, and performance data.

Submit manufacturer's installation instructions.

OPERATION AND MAINTENANCE DATA

Submit under provisions of Section [01700.] [01730.]

Operation Data: Include instructions for safe operating procedures.

Maintenance Data: Include instructions for replacement parts and troubleshooting diagnostics.

FIELD MEASUREMENTS

Verify that field measurements are as [shown on Drawings.] [instructed by manufacturer.]

PART 2 PRODUCTS

MANUFACTURERS

[______________________________] Product [__________.]

[______________________________] Product [__________.]

[______________________________] Product [__________.]

Substitutions: Under provisions of Section [01600.] [_____.]

ELECTRIC DUCT HEATER

Description: Duct-mounted electric resistance heater, with	terminal and control box, coil, casing, and controls.

Input Voltage: [120] [208] [240] [277] [480] [_____] volts, 60 Hz, [single] [three] phase.

Output Rating: [_____] kW, [__________] cu ft/min.

Coil: [Enclosed copper tube, aluminum finned element of coiled nickel-chrome resistance wire centered in tubes and embedded in refractory material.] [Exposed helical coil of nickel-chrome resistance wire with refractory ceramic support bushings.]

Input Fuses: Provide integral fuses for units rated more than 48 amperes full load.

Provide line voltage disconnect switch for each input circuit.

Casing: Die formed channel frame of [16] [14] [18] [___] gage (1.5] [1.8] [1.2] [___] mm) galvanized steel with [3/8 inch (9.5 mm)] mounting holes on [3] [6] [___] inch ([75] [150] [___] mm) centers. Provide tube supports for coils longer than [36] [40] [48] [___] inches ([900]

[1 000] [1 200] [_____] mm).

Provide hinged and latched panel for electrical connection and control compartment.

Controls: Automatic reset thermal cut-out, built-in [magnetic] [mercury] contactors[,][.] [control circuit transformer and fuse,] [manual reset thermal cut-out,] [air flow proving device,] [fused disconnect,] [unfused disconnect,] [load fuses].

Duct Size: [__________] inches ([__________] mm) x [__________] inches ([__________] mm).

Contactor: Provide contactor control for unit.

Provide low voltage control transformer.

Operating Stages: [One.] [Two.] [_____.]

Provide terminal blocks for power and control wiring connections.

ACCESSORIES

Room Thermostats: [Pilot duty wall mounted heating thermostat, rated for [line voltage.] [low voltage.]] [______________________________.]

Mounting Accessories: [_________________________.]

PART 3 EXECUTION

EXAMINATION

Verify that field conditions are acceptable and are ready to receive work.

Verify that required utilities are available, in proper location and ready for use.

Beginning of installation means installer accepts existing conditions.

INSTALLATION

Install in accordance with manufacturer's instructions.

Install unit with sufficient clearance from adjacent construction, piping, ductwork, and other obstructions to allow access for service and maintenance.

Connect power and controls to duct heater as specified in Section 16180.

INTERFACE WITH OTHER PRODUCTS

Install duct heaters in ductwork provided under provisions of Section 15890.

Control duct heater from temperature control system provided under provisions of Section [15973] [15975] [_____.]

FIELD QUALITY CONTROL

Field [inspection and] testing will be performed under provisions of Section [01400.] [01410.]

Verify operation of each electric duct heater by measuring input voltage and current simultaneously for period of ten minutes of continuous operation.

DEMONSTRATION

Provide systems demonstration under provisions of Section [01650.] [_____.]

Demonstrate location of circuit breakers and switches serving duct heater branch circuits, and location and setting procedures for thermostats and other heating controls.

SCHEDULE

Duct Heater DH-1

Voltage: 480 volts, 60 Hz, three phase.

Capacity: 30 kW; 30,000 cu ft/min.

Heating Stages: Six.

Duct Size: 60 inch x 30 inch.

Location: Room 14.

Duct Heater DH-2

Voltage: 480 volts, 60 Hz, three phase.

Capacity: 20 kW; 22,000 cu ft/min.

Heating Stages: Four.

Duct Size: 48 inch x 36 inch.

Location: Room 16.

END OF SECTION