Carrier 39LD, 39LB, 39LA, 39LC, 39LE, 39LF, 39LH03-25, 39LG specifications Electric Heater Installation

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Electric Heaters — Electric heaters may be factory in- stalled or drop shipped to the jobsite and field installed. The heater can only be installed in the preheat-electric section.

To install electric heater, refer to Fig. 31 and proceed as follows:

1.Locate preheat-electric section already mounted on unit and remove protective shipping cover.

2.Locate crate containing electric heater and verify heater matches the unit. Unit hand and heater hands must agree.

3.Remove both knockout slugs (power and signal). Install conduit connectors in top of coil connection box.

4.Remove top panel of the preheat-electric section and drill or punch 2 holes are specified in Fig. 31.

5.Insert the electric heater into unit. It must slide between 2 angles located on the bottom of the section.

6. Secure heater to the preheat-electric section using

4 screws.

7.Locate top panel of section. Run conduit through top pan- el and tighten conduit connectors. Lower top panel and replace panel on unit.

8.Complete wiring per wiring diagram and job require- ments. Follow all applicable local codes.

CONNECT POWER AND CONTROL WIRES — Heater wir- ing schematic is located on control box panel. (Figure 32 shows typical wiring details.) Electrical data for each standard heater arrangement is shown in Table 10. Verify that minimum airflow requirement (minimum coil face velocity, fpm) will be met, especially on applications where variable air volume is supplied.

Use copper power supply wires rated for 75 C minimum. On 250-v or greater applications, use 600-v rated wiring. Size wires to carry 125% of current load on each set of terminals (Table 11). Use the following formulas as required:

Single-phase line current

=1 (kW per set of terminals) (1000)

voltage

Three-phase line current

=(kW per set of terminals) (1000)

(voltage) (1.73)

(kW per set of terminals) (1000) = (voltage) (1.73)

Note that if the heater is rated at 50 kW (or more) and is con- trolled by a cycling device such as a multi-stage thermostat, or a step controller, conductors may be sized at 100% of load amperes (as in Tables 10 and 11) per National Electrical Code (NEC) Section 424-22. Heater construction and application information (Tables 10 and 11) are based upon Underwriters’ Laboratories (UL) Space Heating Standard No. 1096 and the requirements of the NEC. Installer is responsible for observing local code requirements.

Install a disconnect switch or main circuit breaker in accor- dance with NEC and other applicable codes. Locate so that it is easily accessible and within sight of heater control box (per NEC Article 424-19 and 424-65).

Weatherproof junction boxes have no knockouts for wire entrance. Drill or punch holes for conduit as required and make all junctions watertight.

Where field-supplied thermostats are used, isolate circuits to prevent possible interconnection of control circuit wiring.

Where field-supplied step controller is used, connect steps to terminals as marked on wiring schematic. When connecting multi-stage heaters, wire stage no. 1 so that it is first stage on, last stage off. Connect thermostats as required.

Fig. 31 — Electric Heater Installation

Provide sufficient clearance for convection cooling of heat- ers with solid-state controllers. Provide at least 5-in. of free air space above and below cooling fins extending from heater ter- minal box. Be sure to connect interlock terminals F1 and F2 to auxiliary contacts on fan starter.

Each heater has 2 different types of factory-installed ther- mal cutouts for overtemperature protection; an automatic reset thermal cutout for primary protection and a manual reset ther- mal cutout to protect against failure of the primary system. Also provided is an airflow pressure differential switch to pre- vent the heater from operating when the fan is not in operation or airflow is restricted or insufficient. The primary automatic reset cutout is a bi-metal disk-type cutout. It is wired into the control circuit which operates the magnetic disconnecting con- tactors (the same contactors which also switch on and off the various steps of the coil). The secondary manual reset cutout is a bi-metal disk-type cut-out. This secondary thermal cutout is load carrying and is installed in each heater subcircuit. The pri- mary and secondary overtemperature protection systems are independent of each other. The secondary system is designed to protect against possible failure of the primary system to deen- ergize the heater.

Subcircuits in the heaters are designed in compliance with paragraph 424-22 of the NEC. The coil is subdivided into cir- cuits that draw no more than 48 amps each and is fused for at least 125% of the circuit rating.

Pitot tube is to be positioned so that the airflow switch is ac- tuated by a minimum negative pressure of 0.07 in. wg.

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Contents → Safety Considerations ContentsUnit Identification IntroductionPage Preinstallation Size Service Area RequirementsUnit Size Physical DataUnit Rigging Details Mixing Box InstallationMixing Box Damper Operating Torque In.-lb 39L Unit Size TorqueRecommended Actuators Page IGV Actuator Bracket Installation Install Sheaves on Motor and Fan ShaftsDetermining Sheave-Shaft Overhang Cross Belt Small Deflection Force LB SheavePD Range SectionCoil Freeze-Up Protection Water and Steam Coil Piping RecommendationsLow, Medium or High Pressure Coil Piping Dripping Steam Supply to Condensate Return Chilled Water Coil Circuiting Data Steam Coil Connection Sizes Face Split Coil Suction Line Piping Direct Expansion Coil Circuiting Data ROW COIL†† Small Face Area 39LB, 39LC, 39LF Unit Size Circuiting TypeDistributor Part Numbers Side Connector Hot Gas Bypass Data= 1.68 x .33 x Face Split Coil Manifolding Typical Electric Heater Installation Typical Electric Heater Wiring Schematic Steps FLA Electric Heater DataFan Discharge Positions, Fans without IGVs Wire Size Load AmpsBolt Size Torque START-UPFan Motor Replacement ServiceCoil Cleaning GeneralCoil Removal Field-Installed Coils 39LA,LD OnlyHorizontal Unit Slant Coil Removal 39LA Units Sizes Vertical Unit Slant Coil Removal 39LD Units Sizes Page Changing Coil Hand Fan Shaft Bearing Removal FiltersDX and ALL Water Coils Steam Coils Only Filter Arrangement, 2-in. and 4-in. Flat Filter DataLubricant Data LubricationManufacturer Lubricant 39L Unit Size Cutoff Cutoff ClearanceMetric Conversion Chart Copyright 2004 Carrier Corporation

39LG, 39LH03-25, 39LD, 39LE, 39LB specifications

The Carrier 39 series, encompassing models 39LA, 39LF, 39LC, 39LB, and 39LE, represents a prominent line of rooftop packaged units that combine robust performance, energy efficiency, and advanced technology for commercial applications. Designed to provide reliable heating and cooling solutions, these units stand out for their versatility and innovative features.

The 39LA model offers high efficiency and flexibility, making it ideal for various building types. It incorporates advanced economizer capabilities that enhance indoor air quality while reducing energy costs. The unit is equipped with a dual-walled cabinet, which not only improves durability but also ensures quiet operation, making it suitable for noise-sensitive environments.

The 39LF model further enhances energy savings, featuring a unique hybrid heat pump system. This system allows for both heating and cooling through an integrated design, reducing the need for separate systems and streamlining maintenance requirements. The 39LF also boasts high Seasonal Energy Efficiency Ratio (SEER) ratings, contributing to lower operating costs without compromising comfort.

The 39LC variant excels in humid climates, employing advanced dehumidification technologies that effectively manage indoor moisture levels. This model is often utilized in environments such as gyms, restaurants, and hotels where humidity control is vital. Its variable-speed compressors adjust output based on demand, optimizing energy consumption while maintaining consistent comfort levels.

The 39LB model focuses on enhanced filtration and air quality improvements. Its engineered design accommodates high-efficiency particulate air (HEPA) filters, crucial for spaces that require stringent air quality standards. This model also includes smart controls that allow for precise temperature adjustments, ensuring optimal comfort in any setting.

Finally, the 39LE unit emphasizes user-friendly interfaces and smart technology integration. The built-in Wi-Fi capability enables remote monitoring and operation, allowing managers to adjust settings from anywhere, improving overall energy management. Additionally, the 39LE’s compatibility with Building Management Systems (BMS) facilitates seamless integration into existing setups.

In summary, the Carrier 39 series 39LA, 39LF, 39LC, 39LB, and 39LE present a comprehensive array of features designed for various commercial heating and cooling applications. With an emphasis on energy efficiency, advanced air quality management, and user-friendly technology, these units continue to set the standard for rooftop packaged units in the industry. Their innovative characteristics not only enhance comfort but also promote sustainability, making them a smart choice for modern commercial environments.
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