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Keep unit area clear of combustibles and ensure unobstructed airflow for combustion and ventilation.
Warnings regarding electrical shock, explosion, fire, and dangers from improper servicing or wet components.
Information on fiberglass wool exposure risks, including potential cancer and irritation, and how to reduce exposure.
Safety measures before lighting the unit and general operational safety guidelines, including ignition system details.
Detailed instructions for operating gas valves (White Rodgers 36E, Honeywell VR8205M/VR8305Q) during unit startup.
Procedures for safely turning off the gas supply to the furnace, including thermostat and power considerations.
Guidelines for inspecting the burner flame to ensure proper unit operation, including flame characteristics.
Annual inspection of combustion air louvers, vent cap, heat exchanger, and burners for corrosion or debris.
Requirement for yearly servicing by a qualified technician to maintain efficiency and warranty.
Instructions for checking and replacing filters monthly, noting air flow direction during reinstallation.
Procedure for cleaning burners, including removing them, cleaning, and checking the spark gap on the ignition electrode.
Information on lubricating blower shaft bearings every two years with specific lithium base grease.
Reference to tables and figures for manifold pressure specifications and location of pressure ports.
Steps to clean the combustion air inducer wheel and housing, including disconnecting tubing and securing screws.
Instructions for cleaning the flue box and tubes using a wire brush after removing the inducer assembly.
A checklist of common issues to verify before calling a service technician for an inoperative unit.
Guidance on ordering repair parts, emphasizing the need for complete model and serial numbers.
This document serves as a user's information manual for a range of rooftop units, specifically the LGA/LGC series, covering models from 036 to 360, which correspond to various tonnage capacities (3 to 30 tons). The manual provides essential information for the safe operation, maintenance, and servicing of these commercial heating and cooling systems.
The LGA/LGC rooftop units are integrated heating and cooling systems designed for commercial applications. They are equipped with components for both gas-fired heating and refrigerant-based cooling. The heating function involves a combustion air inducer, heat exchanger, and burners to generate warmth, while the cooling function utilizes compressors, evaporator coils, and condenser coils to remove heat from the indoor environment. An economizer, which is an optional feature, allows the unit to use outside air for cooling when conditions are favorable, reducing the need for mechanical refrigeration and improving energy efficiency. Air filters are integral to the system, ensuring that the air circulated throughout the building is clean. The units also include a blower system to distribute conditioned air and a condensate drain to manage moisture removed during the cooling process. Electrical controls manage the operation of all these components, including ignition, fan speeds, and temperature regulation. Safety features, such as flame roll-out switches and limit controls, are incorporated to prevent hazardous conditions.
The manual emphasizes safe and proper usage of the rooftop units. Before operation, users are instructed to ensure the unit area is clear of combustible materials and that there is an unobstructed flow of combustion and ventilating air. The units are equipped with an automatic spark ignition system, eliminating the need for manual lighting. In case of a safety shutdown, the thermostat switch should be moved to OFF and then returned to HEAT to reset the ignition control. For logic units and those with electronic temperature controls, resetting involves turning off and then on the main disconnect.
The process for placing the unit into operation involves setting the thermostat to the lowest setting, turning off all electrical power to the furnace, and then accessing the heat section to manipulate the gas valve knob. Depending on the gas valve model (White Rodgers 36E or Honeywell VR8205/VR8305), specific instructions are provided for turning the knob to "OFF" and then back to "ON" after a five-minute waiting period to clear any residual gas. After the gas valve is set to "ON" and the access panel is closed, electrical power is restored, and the thermostat is set to the desired temperature. The unit will then initiate its ignition sequence. If the furnace does not light on the first attempt, it will try up to two more times before locking out, requiring a repeat of the startup steps. The manual also details the procedure for turning off gas to the furnace, which involves setting the thermostat to the lowest setting and turning off all electrical power before any service is performed.
Regular maintenance is crucial for the efficiency and longevity of the rooftop units. The manual strongly recommends annual servicing by a qualified service technician, stating that failure to provide proof of service can void the warranty.
Key maintenance tasks include:
The manual also includes a "Repair Parts Listing" section, which is essential for identifying and ordering correct replacement parts, emphasizing the need to include the complete model and serial number when ordering. This comprehensive approach to maintenance ensures the safe and efficient operation of the rooftop units throughout their lifespan.
General| Brand | Lennox |
|---|---|
| Model | LGA120 |
| Category | Air Conditioner |
| Language | English |
