Lennox International Inc SL280UH090V48B Equipment in Confined, Space ALL AIR from Inside

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Unconfined Space

An unconfined space is an area such as a basement or large equipment room with a volume greater than 50 cubic feet (1.42 m3) per 1,000 Btu (.29 kW) per hour of the com- bined input rating of all appliances installed in that space. This space also includes adjacent rooms which are not separated by a door. Though an area may appear to be un- confined, it might be necessary to bring in outdoor air for combustion if the structure does not provide enough air by infiltration. If the furnace is located in a building of tight construction with weather stripping and caulking around the windows and doors, follow the procedures in the air from outside section.

Confined Space

A confined space is an area with a volume less than 50 cu- bic feet (1.42 m3) per 1,000 Btu (.29 kW) per hour of the combined input rating of all appliances installed in that space. This definition includes furnace closets or small equipment rooms.

When the furnace is installed so that supply ducts carry air circulated by the furnace to areas outside the space contain- ing the furnace, the return air must be handled by ducts which are sealed to the furnace casing and which terminate outside the space containing the furnace. This is especially important when the furnace is mounted on a platform in a confined space such as a closet or small equipment room. Even a small leak around the base of the unit at the platform or at the return air duct connection can cause a potentially dangerous negative pressure condition. Air for combustion and ventilation can be brought into the confined space either from inside the building or from outside.

 

EQUIPMENT IN CONFINED

CHIMNEY

SPACE ALL AIR FROM INSIDE

 

OR GAS

 

VENT

 

 

WATER

 

HEATER

FURNACE

 

 

OPENINGS

 

(To Adjacent

 

Room)

 

AIR FLOW

NOTE − Each opening shall have a free area of at least one square inch (645 mm2) per 1,000 Btu (.29 kW) per hour of the total input rat- ing of all equipment in the enclosure, but not less than 100 square inches (64516 mm2).

FIGURE 2

Air from Inside

If the confined space that houses the furnace adjoins a space categorized as unconfined, air can be brought in by providing two permanent openings between the two spaces. Each opening must have a minimum free area of 1 square inch (645 mm2) per 1,000 Btu (.29 kW) per hour of total input rating of all gas−fired equipment in the confined space. Each opening must be at least 100 square inches (64516 mm2). One opening shall be within 12 inches (305

mm)of the top of the enclosure and one opening within 12 inches (305 mm) of the bottom. See figure 2.

Air from Outside

If air from outside is brought in for combustion and ventila- tion, the confined space must have two permanent open- ings. One opening shall be within 12 inches (305 mm) of the top of the enclosure and one opening within 12 inches (305

mm)of the bottom. These openings must communicate di- rectly or by ducts with the outdoors or spaces (crawl or at- tic) that freely communicate with the outdoors or indirectly through vertical ducts. Each opening shall have a minimum free area of 1 square inch (645 mm2) per 4,000 Btu (1.17 kW) per hour of total input rating of all equipment in the en- closure. See figures 3 and 4. When communicating with the outdoors through horizontal ducts, each opening shall have a minimum free area of 1 square inch (645 mm2) per 2,000 Btu (.56 kW) per total input rating of all equipment in the enclosure. See figure 5.

When ducts are used, they shall be of the same cross−sec- tional area as the free area of the openings to which they connect. The minimum dimension of rectangular air ducts shall be no less than 3 inches (75 mm). In calculating free area, the blocking effect of louvers, grilles, or screens must be considered. If the design and free area of protective cov- ering is not known for calculating the size opening required, it may be assumed that wood louvers will have 20 to 25 per- cent free area and metal louvers and grilles will have 60 to 75 percent free area. Louvers and grilles must be fixed in the open position or interlocked with the equipment so that they are opened automatically during equipment operation.

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Contents Table of Contents Installation Instructions SL280UHVEither Side Unit Dimensions − inches mmReturn air from both sides Side Return Air OpeningParts Arrangement Access Panel Blower AssemblySight Glass SL280UHV Gas Furnace Safety InformationShipping and Packing List Evaporator Use of Furnace as Construction HeaterGeneral Air Handler UnitCombustion, Dilution & Ventilation Air Space ALL AIR from Inside Equipment in ConfinedEquipment in Confined Space Equipment in Confined Space ALL AIR from OutsideEquipment Confined Space ALL AIR from Outside Bottom Setting EquipmentBlower Motor Rigid LEG Return AIR Base 20 X 25 XFurnace Front Indoor AIRTypical Horizontal Application Horizontal Application Installation Clearances Top LeftRight End BottomDuct System FiltersLeft Side Vent Discharge VentingUpflow Position Top Vent DischargeHorizontal Right Position Horizontal Left PositionSide Vent Discharge Vent Pipe Common Venting Using Metal−Lined Masonry ChimneyDisconnected Vent StickerThrough an unused masonry chimney flue is not considered Vent Connector102 127 −1/2 152 178 10−1/2 MIN MAX Feet FAN + FAN FAN + NAT 130 Carbon Monoxide Poisoning Hazard Every 8 to 10 feet 2.44 to 3.01 m with suitable hang Ers or straps. Install a drip leg in vertical pipe runs to− In some localities, codes may require the installation Gas PipingLeft−Side Air Discharge Horizontal ApplicationRight−Side Air Discharge BOX Interior MAKE−UP BOX InstallationElectrical Electrostatic Discharge ESDCommunicating Non−CommunicatingIcomfortt Integrated Control Outdoor Unit Icomfort Touch Applications NON−COMMUNICATING System WiringCommunicating System Wiring 120V ConnectionsDIP Switch Settings and On−Board Links See figure OFF Single Stage Thermostat w Dual fuel capa Bilities SL280UHV Schematic Wiring Diagram Typical SL280UHV Field Wiring Diagram RS−BUS Link TB82, future use Integrated Control+ = Data High Connection − = Data LOW Connection −10% approx OFF On−Board Links 880 1045985 940SL280UH090V36B Blower Performance less filter 1095 12801220 11551110 12951235 11701100 13601230 11651380 12901225 1160+18% 1605 SL280UH110V60C Blower Performance less filter +18% 1785 SL280UH135V60D Blower Performance less filter Operating Sequence Thermostat energizes Y2 CompressorHoneywell GAS Valve For Your Safety Read Before LightingUnit Start−Up White Rodgers GAS ValveDial Gas Pressure AdjustmentGAS Meter Clocking Chart Proper CombustionHigh Altitude Heating Sequence of Operation Other Unit AdjustmentsHeating Operation with Single Stage Thermostat Heating Operation with TWO−STAGE ThermostatSEC Electrical SHOCK, Fire Or Explosion Hazard Service17− Reinstall burner box, manifold assembly and burner box SL280UHV BURNER, Combustion AIR Inducer Assembly13− To clean the combustion air inducer visually inspect 11− Back wash using steam. Begin from the burner openingSL280UHV NOX Inserts Repair Parts List Planned ServiceIntegrated Control Diagnostic Codes Integrated Control Diagnostic ModesEquipment is unable to communicate. Indicates Normal operation 5 seconds after fault recoveredFurnace / air handler. Clears after fault recovered Power at the thermostat. Alert stops all servicesAte feature will be set as ’installed’ and that could Reconfigure the system. Replace control if heatingMissioning and Execute ’Set Factory Default mode’ Control will still operate on default parameter setTion after fault is cleared Low pressure switch failed openSumes normal operation after fault is cleared Fault is clearedTo flame failure Open or not within specifications −hour soft lockOut. Clears when flame has been proven stable Soft lockout or resetVice is removed, or after power reset Pair/add duct. Cleared after the current service deIs not running. Check power to outdoor unit. Clears Error after current is sensed in both RUNSor run cycle, or after power reset Finished Program Unit Capacity/Size ModeCall for FIRST−STAGE Heat Troubleshooting Heating Sequence of OperationCall for Heat Satisfied Call for SECOND−STAGE Heat2ND Stage Heat Call for Heat Satisfied FIRST−STAGE Heat SECOND−STAGE HeatCall for Cooling Troubleshooting Cooling Sequence of OperationCall for FAN Troubleshooting Continuous Fan Sequence of Operation
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