SERVICE AND REPLACEMENT (See Fig. 30) Ð The 48HJ017,025 units use a fan motor mounting system that features a slide-out motor mounting plate. To replace or serv- ice the motor, slide out the bracket.

1.Remove the evaporator-fan access panel and the heat- ing control access panel.

2.Remove the center post (located between the evaporator fan and heating control access panels) and all screws securing it.

3.Loosen nuts on the two carriage bolts in the motor mount- ing base.

4.Using jacking bolt under motor base, raise motor to top of slide and remove belt. Secure motor in this position by tightening the nuts on the carriage bolts.

5.Remove the belt drive.

6.Remove jacking bolt and tapped jacking bolt plate.

7.Remove the 2 screws that secure the motor mounting plate to the motor support channel.

8.Remove the 3 screws from the end of the motor support channel that interfere with the motor slide path.

9.Slide out the motor and motor mounting plate.

10.Disconnect wiring connections and remove the 4 mount- ing bolts.

11.Remove the motor.

12.To install the new motor, reverse Steps 1-11.

Belt Tension Adjustment Ð To adjust belt tension:

1.Loosen fan motor bolts.

2.a. 015 Units: Move motor mounting plate up or down for proper belt tension (1¤2 in. de¯ection with one ®nger).

b.017,025 Units: Turn motor jacking bolt to move mo- tor mounting plate up or down for proper belt tension (3¤8 in. de¯ection at midspan with one ®nger [9 lb force]).

3.Tighten nuts.

4.Adjust bolts and nut on mounting plate to secure motor in ®xed position.

Condenser-Fan Adjustment

48HJ015,017 UNITS (Fig. 31)

1.Shut off unit power supply.

2.Remove access panel(s) closest to the fan to be adjusted.

3.Loosen fan hub setscrews.

4.Adjust the fan height on the shaft using a straightedge placed across the fan ori®ce.

5.Tighten setscrews and replace panel(s).

6.Turn on unit power.

48HJ025 UNITS (Fig. 32)

1.Shut off unit power supply.

2.Remove fan top-grille assembly and loosen fan hub screws.

3.Adjust fan height on unit, using a straightedge placed across the fan ori®ce.

4.Tighten setscrews and replace rubber hubcap to prevent hub from rusting to motor shaft.

5.Fill hub recess with permagum if rubber hubcap is missing.

Economizer Adjustment Ð Refer to Tables 8 and 9 for economizer checkout procedures. Make certain the outdoor- air damper is fully closed and the return-air damper is fully open before completing the following steps:

1. Turn on power to the unit.

2.Turn the thermostat fan switch to the ON position. The damper will go to the vent position.

3.Adjust the vent position with the minimum position ad- justment on the economizer motor control module. See Fig. 18.

4.Set the system selector switch to COOL position and set the cooling temperature selector to its lowest setting.

NOTE: The Cooling mode may also be simulated by removing the thermostat wires from terminals Y1 and Y2 and installing a jumper between terminals R and Y1. Refer to unit label diagram for terminal locations.

NOTE: A 31¤2-in. bolt and threaded plate are included in the installer's packet. They can be added to the motor support channel below the motor mounting plate to aid in raising the motor.

Fig. 30 Ð 48HJ017,025 Evaporator-Fan

Motor Section

Fig. 31 Ð Condenser Fan Adjustment,

48HJ015,017

Fig. 32 Ð Condenser-Fan Adjustment,

48HJ025

20

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Carrier 48HJ015-025 installation instructions Belt Tension Adjustment Ð To adjust belt tension, Condenser-Fan Adjustment
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48HJ015-025 specifications

The Carrier 48HJ015-025 is a distinguished series of rooftop packaged units renowned for their efficient performance and reliability in light commercial applications. Designed for a variety of indoor environments, these units are engineered to provide efficient heating and cooling solutions, making them suitable for retail spaces, offices, and other commercial buildings.

One of the main features of the Carrier 48HJ series is its advanced scroll compressor technology, which enhances the overall efficiency of the systems. This type of compressor is known for its durability and quiet operation, providing consistent temperature control while minimizing energy consumption. The use of a scroll compressor contributes to a higher Seasonal Energy Efficiency Ratio (SEER) and Heating Seasonal Performance Factor (HSPF), making these units a smart choice for energy-conscious businesses.

Additionally, the 48HJ series incorporates a multi-speed indoor blower that allows for precise airflow control. This feature ensures optimal indoor comfort by adjusting the air distribution based on the specific heating or cooling needs of the space. The ability to adapt to varying load conditions enhances efficiency and reduces energy wastage.

Another noteworthy characteristic of the Carrier 48HJ015-025 is its robust construction. Built with galvanized steel, the units are designed to withstand harsh environmental conditions, ensuring longevity and minimal maintenance requirements. The powder-painted finish offers corrosion resistance, contributing to the unit’s durability over time.

The series also integrates advanced controls for ease of operation. The user-friendly thermostat enables precise temperature management and can be programmed according to the specific needs of the facility. Moreover, compatibility with Building Management Systems (BMS) facilitates seamless integration into existing infrastructure, enabling remote monitoring and enhanced operational efficiency.

In terms of environmental considerations, the Carrier 48HJ series utilizes R-410A refrigerant, which is known for its reduced impact on the ozone layer compared to older refrigerants. This commitment to sustainability aligns with modern environmental standards and regulations.

Overall, the Carrier 48HJ015-025 stands out as a versatile and efficient rooftop packaged unit, perfect for varying commercial applications. Its combination of advanced technology, reliability, and user-focused design makes it a prominent choice for businesses seeking optimized climate control solutions while ensuring sustainability and energy efficiency.
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