Pilot Adjustment, Gas Valve Adjustment

Fig. 34 Ð Cooling Charging Chart, 48HJ017

Fig. 35 Ð Cooling Charging Chart, 48HJ025

Pilot Adjustment

1.Set system selector switch at OFF position to shut off unit. Turn off power to unit.

2.Remove screw cap cover on pilot gas valve to expose adjusting screw (See Fig. 36).

3.Turn valve knobs to pilot position.

4.Turn on power to unit. Set system selector switch to HEAT position and set thermostat to a setting that will call for heat. Pilot ignites.

5.With a small screwdriver, turn adjustment screw until flame fully engulfs sensor. Flame can be observed through view port (Fig. 37).

6.Turn off power to unit. Replace cap on pilot gas valve. Return valve knob(s) to original position.

7.Check for proper burner operation by cycling the burn- ers. Wait 30 seconds between burner cycles.

8.Check that all unit panels are in place before leaving unit.

Gas Valve Adjustment

NATURAL GAS Ð The gas valve opens and closes in re- sponse to the thermostat or limit control.

When power is supplied to valve terminals 3 and 4, the pilot valve opens to the preset position. When power is sup- plied to terminals 1 and 2, the main valve opens to its preset position.

The regular factory setting is stamped on the valve body (3.5 in. wg).

To adjust regulator:

1.Set thermostat at setting for no call for heat.

2.Turn main gas valve to OFF position.

3.Remove 1¤8-in. pipe plug from manifold or gas valve pres- sure tap connection. Install a suitable pressure-measuring device.

4.Set main gas valve to ON position.

5.Set thermostat at setting to call for heat.

6.Remove screw cap covering regulator adjustment screw (See Fig. 36).

7.Turn adjustment screw clockwise to increase pressure or counterclockwise to decrease pressure.

8.Once desired pressure is established, set thermostat set- ting for no call for heat, turn off main gas valve, remove pressure-measuring device and replace 1¤8-in. pipe plug and screw cap.

Fig. 36 Ð Gas Valve

VIEW	PRIMARY AIR	FLUE BOX
PORT	SHUTTER	COVER

MAIN BURNER

SECTION

Fig. 37 Ð Typical Heating Section

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.