NOTE TO INSTALLER:
This manual should be left with the equipment owner.
General Safety Warnings
WARNING: If the information in this manual is not followed exactly, a fire or explosion may result causing property damage, personal injury or loss of life. Do not store or use gasoline or other flammable vapors and liquids in the vicinity of this or any other appliance.
WHAT TO DO IF YOU SMELL GAS:
- Do not try to light any appliance.
- Do not touch any electrical switch; do not use any phone in your building.
- Immediately call your gas supplier from a neighbor's phone. Follow the gas supplier's instructions.
- If you cannot reach your gas supplier, call the fire department.
Installation and service must be performed by a qualified installer, service agency or the gas supplier.
AVERTISSEMENT (French): RISQUE D'INCENDIE OU D'EXPLOSION. Si les consignes de sécurité ne sont pas suivies à la lettre, cela peut entraîner la mort, de graves blessures ou des dommages matériels. Ne pas entreposer ni utiliser d'essence ni autres vapeurs ou liquides inflammables à proximité de cet appareil ou de tout autre appareil. QUE FAIRE SI UNE ODEUR DE GAZ EST DÉTECTÉE: Ne mettre en marche aucun appareil. Ne toucher aucun interrupteur électrique; ne pas utiliser de téléphone dans le bâtiment. Quitter le bâtiment immédiatement. Appeler immédiatement le fournisseur de gaz en utilisant le téléphone d'un voisin. Suivre les instructions du fournisseur de gaz. Si le fournisseur de gaz n'est pas accessible, appeler le service d'incendie. L'installation et l'entretien doivent être effectués par un installateur ou une entreprise d'entretien qualifié, ou le fournisseur de gaz.
WARNING: Do not use this furnace if any part has been under water. A flood-damaged furnace is extremely dangerous. Attempts to use the furnace can result in fire or explosion. A qualified service agency should be contacted to inspect the furnace and to replace all gas controls, control system parts, electrical parts that have been wet or the furnace if deemed necessary.
AVERTISSEMENT (French): Ne pas utiliser cet appareil de chauffage s'il a été en partie immergé dans l'eau. Un appareil de chauffage endommagé par une inondation est extrêmement dangereux. S'il est utilisé, un incendie ou une explosion peut se produire. Il faut avoir recours à une entreprise d'entretien qualifiée pour faire inspecter l'appareil de chauffage et remplacer toutes les commandes de gaz, les pièces du système de contrôle, les pièces électriques qui sont entrées en contact avec l'eau ou l'appareil de chauffage lui-même, si cela est jugé nécessaire.
WARNING: Improper installation, adjustment, alteration, service or maintenance can cause injury or property damage. Refer to this manual. For assistance or additional information consult a qualified installer, service agency, or the gas supplier.
WARNING: Before performing recommended maintenance, be sure main power switch to unit is turned off and lockout tag is installed. Electrical shock could cause personal injury.
Your combination heating/cooling rooftop unit is equipped with an automatic direct spark ignition system and induced-draft power combustion blower.
WARNING: Burners will light automatically. Do not attempt to light by hand; personal injury may result.
Carbon Monoxide Hazard
WARNING: CARBON-MONOXIDE POISONING HAZARD. Failure to follow instructions could result in severe personal injury or death due to carbon-monoxide poisoning, if combustion products infiltrate into the building.
- Check that all openings in the outside wall around the vent (and air intake) pipe(s) are sealed to prevent infiltration of combustion products into the building.
- Check that furnace vent (and air intake) terminal(s) are not obstructed in any way during all seasons.
AVERTISSEMENT (French): RISQUE D'INTOXICATION AU MONOXYDE DE CARBONE. Si ces directives ne sont pas suivies, cela peut entraîner des blessures graves ou une intoxication au monoxyde de carbone pouvant causer la mort, si des produits de combustion s'infiltrent dans le bâtiment. Vérifier que toutes les ouvertures pratiquées dans le mur extérieur autour du ou des tuyaux d'évent (et de la prise d'air) sont scellées de manière à empêcher l'infiltration de produits de combustion dans le bâtiment. Veiller à ce que la ou les sorties de l'évent de l'appareil de chauffage (et la prise d'air) ne soient, en aucune façon, obstruées, quelle que soit la saison.
Overheating and Gas Supply Warning
WARNING: Should overheating occur or the gas supply fail to shut off, shut off the manual gas valve to the unit before shutting off the electrical supply.
AVERTISSEMENT (French): En cas de température excessive, ou s'il est impossible de couper l'alimentation en gaz, fermer le robinet manuel d'alimentation en gaz du générateur d'air chaud avant de couper l'alimentation électrique.
Fire Hazard Warnings
WARNING: FIRE HAZARD. Failure to follow this warning could result in personal injury, death, and/or property damage. Inlet pressure tap set screw must be tightened and 1/8-in. NPT pipe plug must be installed to prevent gas leaks.
Diagram Description (Fig. 1, Page 2): Shows a gas valve with an inlet pressure tap and set screw, indicating the need for a tightened set screw and a 1/8-in. NPT pipe plug.
WARNING: FIRE HAZARD. Failure to follow this warning could result in personal injury, death, and/or property damage. Manifold pressure tap set screw must be tightened and 1/8-in. NPT pipe plug must be installed to prevent gas leaks.
Diagram Description (Fig. 1, Page 2): Shows a gas valve with a manifold pressure tap and set screw, indicating the need for a tightened set screw and a 1/8-in. NPT pipe plug.
To Light Unit
DANGER:
- Do not turn off the electrical power to unit without first turning off the gas supply.
- Before attempting to start the gas heating section, familiarize yourself with all the procedures that must be followed.
- Never attempt to manually light the burners on the unit with a match, lighter, or any other flame. If the electric sparking device fails to light the burners, refer to the shutdown procedures, then call your dealer as soon as possible.
If you do not follow these instructions exactly, a fire or explosion may result, causing property damage, injury, or loss of life.
Diagram Description (Fig. 2, Page 4): Illustrates the steps to light the unit using the scrolling marquee interface. It shows steps involving the ESCAPE and ENTER keys, a SERVICE TEST LED, toggling displays (STOP, NO/YES), and moving gas valve switches to ON/OFF. It also depicts a lockout tag procedure.
WARNING: If the main burners fail to light or the blower fails to start, shut down gas heating section and call your dealer for service. Failure to follow these requirements could result in serious personal injury.
For normal operation, ensure units with conventional thermostats are set to heating control temperature. For VAV and constant volume units with a space temperature sensor, ensure set points are at normal heat set points.
To Shut Unit Off
WARNING:
- Do not turn off the electrical power to unit without first turning off the gas supply.
- Never attempt to manually light the main burners on unit with a match, lighter, or any other flame. If the electric sparking device fails to light the main burners, refer to the following shutdown procedures. Call your dealer as soon as possible.
Failure to follow these procedures can result in serious fire or personal injury.
IMPORTANT: Should overheating occur or the gas supply fail to shut off, shut off the manual gas valve to the unit before shutting off the electrical supply.
Do not use this unit if any part has been under water. Immediately call a qualified service technician to inspect the unit and to replace any part of the control system and gas control that has been under water.
Diagram Description (Fig. 3, Page 5): Illustrates the steps to shut down the unit. It shows similar interface interactions as Fig. 2, including ESCAPE, ENTER, SERVICE TEST LED, and toggling displays. It also depicts closing the manual gas shutoff valve, turning off electrical power with a lockout tag, and moving gas valve switches to OFF.
Heat Section Details
Diagram Description (Fig. 1, Page 3): Shows schematic layouts of heat sections for different unit sizes.
- 030-050 SIZES: Notes that high heat uses sections 1 and 2, while low heat uses section 1 only. Components shown include LIMIT SWITCH NO. 1, LIMIT SWITCH NO. 2, FLUE OUTLET, and GAS VALVE.
- 055-100 SIZES LOW HEAT: Notes that high heat uses sections 1-3, and low heat uses sections 1 and 2 only. Components shown include LIMIT SWITCH NO. 1, LIMIT SWITCH NO. 2, FLUE OUTLET, and GAS VALVE.
- 055-100 SIZES HIGH HEAT: Similar to the low heat description, indicating sections 1-3 for high heat and 1 and 2 for low heat.
Unit Operation Procedures
Follow these steps to prepare the unit for operation:
- Turn off the unit demand for cooling or heating using the scrolling marquee in the control box.
- Push the [ESCAPE] key until a blank display screen is shown.
- Push the [key] until the SERVICE TEST LED is lit.
- Push the [ENTER] key. The display will show STOP.
- Push the [ENTER] key again. The NO/YES display will flash.
- Push the [▲] or [▼] key to toggle the display to YES and then push [ENTER]. The unit will be locked off from heating, cooling, or any operation. Controls and display will still function.
- Close the field-installed manual gas shutoff valve.
- Turn off the electrical power to the unit using the disconnect or field-installed disconnect and apply proper lockout and tag-out procedures.
- Open the burner section hinged access door.
- Move the switch on the gas valves to the OFF position and wait 5 minutes.
- NOTE: If this is the first installation, gas flue hoods must be installed before operating the unit.
- Move the switch on the gas valves to the ON position.
- Close the burner section hinged access door.
- Turn on the electrical supply to the units.
- Open the field-installed manual gas valve.
To enable the unit to run:
- Using the scrolling marquee, enable the unit to run:
- Push the [ESCAPE] key until a blank display screen is shown.
- Push the [key] until the SERVICE TEST LED is lit.
- Push the [ENTER] key. The display will show STOP.
- Push the [ENTER] key again. The NO/YES display will flash.
- Push the [▲] or [▼] key to toggle the display to NO and then push [ENTER]. The unit will return to normal operation and exit SERVICE TEST mode.
- To test the operation of the gas section, use the scrolling marquee Service Test routine to energize gas outputs and turn on gas. Refer to the unit Controls, Start-Up, Operation, Service and Troubleshooting literature for more information.
- For normal operation, ensure units with conventional thermostats are set to heating control temperature. On VAV and constant volume units with a space temperature sensor, ensure set points are at normal heat set points.
Maintaining Your Unit
All maintenance should be handled by skilled, experienced personnel. Carrier dealers can help establish a standard procedure.
For safety, keep the gas heating area clear and free of combustible materials, gasoline, and other flammable liquids and vapors. Ensure proper functioning by keeping combustion and ventilating air flow unobstructed. A clearance of at least 4 ft on all sides is required.
WARNING:
- TURN OFF GAS SUPPLY AND THEN ELECTRICAL POWER TO YOUR UNIT BEFORE SERVICING OR PERFORMING MAINTENANCE.
- Do not turn off electrical power to this unit without first turning off the gas supply.
- When removing access panels or performing maintenance functions inside your unit, be aware of sharp sheet metal parts and screws. Be extremely careful when handling parts or reaching into the unit.
Failure to follow these procedures can result in serious fire or personal injury.
Routine Maintenance and Care for the Equipment Owner
Air Filters
Air filters should be checked at least every 3 or 4 weeks and changed or cleaned when dirty. Table 1 indicates the correct filter size. Open the hinged filter access door to replace or inspect filters. Filters slide into tracks; remove by pulling outward. Note flow arrows on filter frame.
Diagram Description (Fig. 4, Page 7): Shows the location of various access doors on different unit models (48P 030, 035; 48P 040-070; 48P 075-100), including POWER EXHAUST ACCESS DOOR, FILTER ACCESS DOOR, and GAS SECTION ACCESS DOOR. It also labels AIR HOODS and GAS BURNERS.
Table 1 — Indoor-Air Filter Data
| 48P UNIT SIZE | FILTER TYPE | QUANTITY...Size (in.) |
|---|---|---|
| 030-050 | Disposable Fiberglass (Standard) or Medium Efficiency 30% Pleated (Optional) | 8...20 x 25 x 2, 8...20 x 20 x 2 |
| 90% Bag (Optional) with High Velocity Pre-Filters | 6...20 x 24 x 22, 6...20 x 20 x 22, 12...16 x 20 x 2, 3...20 x 24 x 2 | |
| 055-070 | Disposable Fiberglass (Standard) or Medium Efficiency 30% Pleated (Optional) | 12...20 x 25 x 2, 12...20 x 25 x 2 |
| 90% Bag (Optional) with High Velocity Pre-Filters | 6...24 x 24 x 22, 6...24 x 20 x 22, 6...24 x 24 x 2, 6...20 x 24 x 2 | |
| 075 | Disposable Fiberglass (Standard) or Medium Efficiency 30% Pleated (Optional) | 12...20 x 25 x 2, 12...20 x 20 x 2 |
| High Efficiency 65% Pleated (Optional) | 12...20 x 25 x 2, 12...20 x 20 x 2 | |
| 090,100 | Disposable Fiberglass (Standard) or Medium Efficiency 30% Pleated (Optional) | 12...20 x 25 x 2, 12...20 x 20 x 2 |
| High Efficiency 65% Pleated (Optional) | 12...20 x 25 x 2, 12...20 x 20 x 2 |
*See base unit Installation Instructions if field-supplied or optional factory-supplied filters are used. When replacing filters, always use the same type and size originally supplied.
Contact your Carrier dealer for filter location or maintenance questions.
When replacing filters, always use the same size and type originally supplied.
Units with outdoor air capability have a cleanable outdoor air filter. Check and clean annually as necessary. Remove by unscrewing the retainer and sliding filters out.
WARNING: Never operate your unit without filters in place. Failure to heed this warning may result in damage to the blower motor and/or compressor. Accumulation of dust and lint can cause loss of efficiency and, in some cases, fire.
Heat Exchanger
For dependable and efficient heating, the heat exchanger should be checked by a qualified maintenance person before each heating season and cleaned when necessary. This should only be done by qualified personnel with the required expertise and equipment. Checking/cleaning involves removing gas controls and flue collector box cover, then reinstalling for proper operation. Contact your Carrier dealer for required periodic maintenance.
Fan and Belts
Periodically check fan wheels, housings, and belt tension. Call your Carrier dealer for service.
Evaporator-Fan Motor, Condenser-Fan Motor and Combustion-Fan Motor
Lubrication is not recommended. Bearings typically do not require lubrication for at least 5 years. After 5 years, motors can be serviced at an authorized motor service shop.
Fan Shaft Bearings
Charge fittings annually with Shell Alvania No. 2 or equivalent grease.
Evaporator and Condenser Coils
Cleaning of the coils should only be done by qualified service personnel. Contact your Carrier dealer for required maintenance.
Condensate Drain
The drain pan and condensate drain line should be checked and cleaned concurrently with the cooling coils.
Compressors
All compressors are factory shipped with the correct type and charge of refrigeration grade oil. Service technicians must ensure the proper oil level is maintained in the compressor when it is installed and running.
Combustion Area and Vent System
The combustion area and vent system should be visually inspected before each heating season. Accumulation of dirt, soot, rust, and scale can reduce efficiency and performance. Accumulation on the burner crossover tube can lead to delayed ignition, characterized by a loud sound.
CAUTION: If your unit makes unusual or especially loud noises during heating, shut down the heating section and call your Carrier dealer.
Inspect the combustion area and power-venting system:
- Turn off gas supply and then electrical power to your unit.
- Open gas section access door.
- Using a flashlight, carefully inspect the burner areas for dirt, soot, rust, or scale.
CAUTION: If dirt, soot, rust, or scale accumulations are found, call your Carrier dealer and do not operate your heating section.
- When inspection is complete, follow start-up procedures in this manual to restore unit operation.
- Observe unit heating operation and burner flame core color. The flame core should be bright blue. If a malfunction is suspected, or if flame cores are not bright blue, call your Carrier dealer.
Diagram Description (Fig. 5, Page 8): Illustrates the proper appearance of a burner flame, showing the flame tip and flame core, emphasizing the ideal bright blue color.
NOTE: Burner flame cores with orange, yellow, or red flames mixed with blue may indicate inefficient gas burning. Your Carrier dealer may need to adjust the air/gas mixture.
- Replace gas section access panel.
Unit Panels and Doors
After performing any maintenance or service, ensure all panels and doors are securely fastened to prevent rain entry and to maintain correct unit airflow.
Regular Dealer Maintenance
Your unit should be inspected regularly by a properly trained service technician (preferably annually, but at least every other year). An inspection should include:
- Inspection of all flue product passages (burners, heat exchanger, flue collector box, vent pipe).
- Inspection of all combustion-air and ventilation-air passages and openings.
- Close inspection of all gas pipes leading to and inside the unit.
- Adjustment of the air/gas mixture if burner flames are not bright blue (refer to Fig. 4 and 5 for access panel and flame appearance).
- Inspection, and if required, cleaning of the condenser and evaporator coils.
- Inspection, and if required, cleaning of the evaporator drain pan.
- Inspection, cleaning, and lubrication of blower wheel housing and motor.
- Inspection of all supply-air and return-air ducts for leaks, obstructions, and insulation integrity. Resolve any problems found.
- Inspection of the unit base for cracks or gaps that could cause a hazardous condition.
- Inspection of the unit casing for signs of deterioration.
- Inspection of all electrical wiring and components for proper connection.
- Inspection for leaks in the refrigerant circuit. Perform pressure-check for appropriate refrigerant charge.
- Operational check of the unit to determine working conditions. Repair or adjust as needed.
Your servicing dealer may offer an economical service contract for seasonal inspections.
Complete Service Instructions are found in the base unit Controls, Start-Up, Operation, Service and Troubleshooting literature.
Before You Call for Service, Check for Easily Solved Problems
If Insufficient Heat or Cooling is Suspected:
- Check for sufficient airflow. Check air filters for dirt.
- Check for blocked return-air or supply-air grilles. Ensure they are open and unobstructed.
- Verify heating and cooling set points are correct.
- If these checks do not reveal the cause, contact your servicing dealer.
If Your Unit is Not Operating at All:
- Check that the heating temperature set point is set above the indoor temperature (for heating season), or the cooling temperature set point is below the indoor temperature (for cooling season).
- Ensure the unit on/off switch is in the ON position.
- Verify the unit has been programmed with appropriate time schedules and desired operating set points.
- Check if the electrical supply switch is ON. Check for blown fuses or tripped circuit breakers.
- During the heating season, check the manual shutoff valve. Ensure the lever is parallel with the pipe (open). If closed, check if gas has been shut off for safety reasons. If not, open the valve and follow start-up procedures.
- NOTE: Before proceeding with the next check, turn OFF the electrical power supply to the unit and open the control access door.
- During the heating season, check the control switch on the gas valve. Ensure it is in the ON position. Follow start-up procedures if necessary.
- If your unit still fails to operate, contact your servicing dealer for troubleshooting and repairs. Provide the unit's model and serial numbers.
In Case of Trouble
If, after performing the above checks, unit performance is unsatisfactory, shut off the unit and call your Carrier dealer.
Dealer's Name: _____________________________________
Telephone No.: _____________________________________
Unit Model: ________________________________________
Unit Serial Number: _________________________________
Unit Address: ______________________________________
Bus Number: _______________________________________
