Lennox KGA Series Service Literature
Lennox KGA Series Service Literature

Lennox KGA Series Service Literature

Units 7.5 to 12.5 ton, 26.3 to 42 kw

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Service Literature
The KGA 7.5, 8.5, 10 and 12.5 ton (092, 102, 120, 150)
packaged gas units are available in standard cooling effi­
ciency. Units are available in 130,000, 180,000 or
240,000Btuh (38.1, 52.7 or 70.3 kW) heating inputs. Gas
heat sections are designed with aluminized steel tube heat
exchangers.
All KGA units are designed to accept any of several different
energy management thermostat control systems with mini­
mum field wiring. Factory- or field-provided control options
connect to the unit with jack plugs. When "plugged in" the
controls become an integral part of the unit wiring.
Information contained in this manual is intended for use by
qualified service technicians only. All specifications are sub­
ject to change. Procedures outlined in this manual are pre­
sented as a recommendation only and do not supersede or
replace local or state codes.
If the unit must be lifted for service, rig unit by attaching four
cables to the holes located in the unit base rail (two holes at
each corner). Refer to the installation instructions for the proper
rigging technique.
WARNING
Improper installation, adjustment, alteration, service
or maintenance can cause property damage, person­
al injury or loss of life. Installation and service must
be performed by a qualified installer or service
agency.
ELECTROSTATIC DISCHARGE (ESD)
Precautions and Procedures
CAUTION
Electrostatic discharge can affect electronic
components. Take precautions during unit instal­
lation and service to protect the unit's electronic
controls. Precautions will help to avoid control
exposure to electrostatic discharge by putting
the furnace, the control and the technician at the
same electrostatic potential. Neutralize electro­
static charge by touching hand and all tools on an
unpainted unit surface, such as the gas valve or
blower deck, before performing any service pro­
cedure.
Corp. 1010-L8
Revised 07/2015
KGA092 through 150
Danger of sharp metallic edges. Can cause injury.
Take care when servicing unit to avoid accidental
contact with sharp edges.
Options / Accessories
Specifications
Blower Data
Electrical Data
Parts Arrangement
I- Unit Components
II- Placement and Installation
III- Start-Up
IV- Charging
V- System Service Checks
VI- Maintenance
VII- Accessories
VIII-Wiring Diagrams
Page 1
KGA UNITS
7.5 to 12.5 ton
26.3 to 42 kW
CAUTION
WARNING
Electric shock hazard. Can cause injury
or death. Before attempting to perform
any service or maintenance, turn the
electrical power to unit OFF at discon­
nect switch(es). Unit may have multiple
power supplies.
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© 2015.

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Summary of Contents for Lennox KGA Series

  • Page 1 KGA UNITS Service Literature 7.5 to 12.5 ton Corp. 1010-L8 26.3 to 42 kW Revised 07/2015 KGA092 through 150 The KGA 7.5, 8.5, 10 and 12.5 ton (092, 102, 120, 150) packaged gas units are available in standard cooling effi­ ciency.
  • Page 2: Options & Accessories

    OPTIONS / ACCESSORIES Unit Model No Model Catalog Item Description Number Number 092 102 120 COOLING SYSTEM Compressor Crankcase Heater 208/230V-3ph - K1CCHT02B-1Y 54W17 54W18 460V-3ph - K1CCHT02B-1G 575V-3ph - K1CCHT02B-1J 54W19 Condensate Drain Trap PVC - LTACDKP09/36 76M18 Copper - LTACDKC09/36 76M19 Corrosion Protection Factory...
  • Page 3: Indoor Air Quality

    OPTIONS / ACCESSORIES Unit Model No Model Catalog Item Description Number Number 092 102 120 CABINET Coil Guards K1GARD20B-1 55W08 Hail Guards K1GARD10B1 55W11 Hinged Access Panels Factory Horizontal Discharge Kit K1HECK00B-1 51W25 Return Air Adaptor Plate (for L Series and T-Class™...
  • Page 4: Outdoor Air

    OPTIONS / ACCESSORIES Unit Model No Model Catalog Item Description Number Number 092 102 120 ECONOMIZER Economizer Economizer with Single Temperature Control - Downflow or K1ECON20B-1 54W55 Horizontal With Barometric Relief Dampers (downflow) and Air Hoods Economizer Controls Single Enthalpy Control C1SNSR64FF1 53W64 Differential Enthalpy Control (order 2)
  • Page 5: Specifications

    SPECIFICATIONS General Data Nominal Tonnage 7.5 Ton 8.5 Ton 10 Ton 12.5 Ton Model Number KGA092S4B KGA102S4B KGA120S4B KGA150S4B Efficiency Type Standard Standard Standard Standard Blower Type Constant Air Constant Air Constant Air Constant Air Volume CAV Volume CAV Volume CAV Volume CAV Cooling Gross Cooling Capacity - Btuh...
  • Page 6: Specifications - Gas Heat

    SPECIFICATIONS - GAS HEAT Heat Input Type Standard Medium High Number of Gas Heat Stages Gas Heating Input - Btuh First Stage 84,500 117,000 156,000 Performance Second Stage 130,000 180,000 240,000 Output - Btuh Second Stage 104,000 144,000 192000 Temperature Rise Range - °F 15-45 30-60 40-70...
  • Page 7: Blower Data

    BLOWER DATA 092 AND 102 BELT DRIVE BLOWER − BASE UNIT BLOWER TABLE INCLUDES RESISTANCE FOR BASE UNIT ONLY (NO HEAT SECTION) WITH DRY INDOOR COIL AND AIR FILTERS IN PLACE. FOR ALL UNITS ADD: 1 − Wet indoor coil air resistance of selected unit. 2 −...
  • Page 8 BLOWER DATA 120 BELT DRIVE BLOWER − BASE UNIT BLOWER TABLE INCLUDES RESISTANCE FOR BASE UNIT ONLY (NO HEAT SECTION) WITH DRY INDOOR COIL AND AIR FILTERS IN PLACE. FOR ALL UNITS ADD: 1 − Wet indoor coil air resistance of selected unit. 2 −...
  • Page 9 BLOWER DATA 150 BELT DRIVE BLOWER − BASE UNIT BLOWER TABLE INCLUDES RESISTANCE FOR BASE UNIT ONLY (NO HEAT SECTION) WITH DRY INDOOR COIL AND AIR FILTERS IN PLACE. FOR ALL UNITS ADD: 1 − Wet indoor coil air resistance of selected unit. 2 −...
  • Page 10 BLOWER DATA FACTORY INSTALLED BELT DRIVE KIT SPECIFICATIONS Nominal Maximum Drive Kit Number RPM Range 590 - 890 800 - 1105 795 - 1195 3.45 730 - 970 3.45 940 - 1200 3.45 1015 - 1300 5.75 900 - 1135 5.75 1040 - 1315 5.75...
  • Page 11 BLOWER DATA CEILING DIFFUSERS AIR RESISTANCE - in. w.g. RTD11 Step-Down Diffuser FD11 Flush Air Volume 1 Side, 2 Ends All Ends & Sides Diffuser Unit Size 2 Ends Open Open Open 2400 0.21 0.18 0.15 0.14 2600 0.24 0.21 0.18 0.17 2800...
  • Page 12 ELECTRICAL DATA 7.5 TON 7.5 TON STANDARD EFFICIENCY (R-410A) KGA092S4 Voltage - 60hz 208/230V - 3 Ph 460V - 3 Ph 575V - 3 Ph Compressor 1 Rated Load Amps 13.1 Locked Rotor Amps 83.1 Compressor 2 Rated Load Amps 13.1 Locked Rotor Amps 83.1...
  • Page 13: Electrical Data 10 Ton

    ELECTRICAL DATA 10 TON 10 TON STANDARD EFFICIENCY (R-410A) KGA120S4 Voltage - 60hz 208/230V - 3 Ph 460V - 3 Ph 575V - 3 Ph Compressor 1 Rated Load Amps Locked Rotor Amps 38.9 Compressor 2 Rated Load Amps Locked Rotor Amps 38.9 Outdoor Fan Full Load Amps...
  • Page 14 KGA PARTS ARRANGEMENT DISCONNECT / CIRCUIT BREAKER BLOWER EVAPORATOR CONDENSER (FACTORY- OR FIELD- MOTOR COIL FANS ECONOMIZER INSTALLED OPTION) CONDENSER (OPTIONAL) COIL BLOWER COMBUSTION AIR INDUCER GAS VALVE COMPRESSORS FILTERS BURNERS CONDENSATE (FOUR - 20 X 25 X 2”) DRAIN FIGURE 1 KGA CONTROL BOX - Y, G, J-VOLT UNITS KGA CONTROL BOX - M VOLT CE UNITS...
  • Page 15: I-Unit Components

    I-UNIT COMPONENTS 5-Condenser Fan Capacitors C1 & C2 All 7.5 through 12.5 ton (26.3 through 44 kW) units are con­ Fan capacitors C1 and C2 are used to assist in the start up of figure to order units (CTO). The KGA unit components are condenser fans B4 and B5.
  • Page 16 KGA092,102, 120, 150 PLUMBING AND COMPRESSOR CIRCUITS DETAIL OUTDOOR COIL STAGE 2 INDOOR COIL STAGE 2 INDOOR COIL STAGE 1 DRIERS OUTDOOR COIL STAGE 1 COMPRESSOR COMPRESSOR COMPRESSOR 2 COMPRESSOR 1 S8 THERMAL S5 THERMAL SUCTION PROTECTOR PROTECTOR LINE SUCTION DISCHARGE LINE LINE...
  • Page 17 When liquid pressure in both refrigerant circuits If Interlink compressor replacement is necessary, call drops to 240 ± 10 psig (1655 ± 69 kPa), the switches open 1-800-4-LENNOX (1-800-453-6669). and the condenser fans are de-energized. This intermittent fan operation results in higher evaporating temperature al­...
  • Page 18: Operation / Adjustment

    C-Blower Compartment tions provided with thermostat. Unit will cycle on thermostat demand. The following steps apply to applications using a The blower compartment in all KGA092/150S units is located typical electro-mechanical thermostat. between the evaporator coil and the condenser coil section. The blower assembly is accessed by disconnecting the blow­...
  • Page 19: Pulley Alignment

    4- The blower RPM can be adjusted at the motor pulley. Check Belt Tension Loosen Allen screw and turn adjustable pulley clock­ Overtensioning belts shortens belt and bearing life. Check wise to increase CFM. Turn counterclockwise to de­ belt tension as follows: crease CFM.
  • Page 20 Each orifice and burner are sized specifically to the unit. dium heat and one six-tube/burner for standard heat. Burn­ Refer to Lennox Repair Parts Listing for correct sizing infor­ ers in all units use a burner venturi to mix gas and air for mation.
  • Page 21: Gas Valve Regulation

    The inducer begins operating fire. Figures 17 and 18 show gas valve components. Table immediately upon receiving a thermostat demand and is 3 shows factory gas valve regulation for KGA series units. de-energized when thermostat demand is satisfied. TABLE 3 The inducer uses a 208/230V single‐phase PSC motor...
  • Page 22 9-Spark Electrode Figure 13 ground electrode (located on the spark electrode), through the flame, and into the sensing electrode. The ig­ An electrode assembly is used for ignition spark. The elec­ nition control allows the gas valve to stay open as long as a trode is inserted through holes under the left-most burner.
  • Page 23 Rollout switch open / Prove switch open or 3 Flashes IGNITION CONTROL A3 closed. 4 Flashes Primary High Limit switch open. 5 Flashes Flame sensed but gas valve not open. 6 Flashes On Board Microprocessors Disagree TABLE 5 P2 TERMINAL DESIGNATIONS Pin # Function R 24 Volts to thermostat...
  • Page 24: For Your Safety Read Before Lighting

    II-PLACEMENT AND INSTALLATION WARNING Make sure the unit is installed in accordance with the in­ stallation instructions and all applicable codes. See ac­ Electric shock hazard. Can cause cessories section for conditions requiring use of the op­ injury or death. Before attempting to tional roof mounting...
  • Page 25 12- If the appliance does not light the first time (gas line WHITE RODGERS 36C76 GAS VALVE not fully purged), it will attempt up to two more ignitions before locking out. HIGH FIRE MANIFOLD PRESSURE ADJUSTMENT SCREW UNDER CAP MANIFOLD INLET 13- If lockout occurs, repeat steps 1 through 10.
  • Page 26: Refrigerant Circuits

    5- Make sure the connections are tight. listed for sea level applications at 80°F dry bulb and 67°F wet bulb return air. Discharge and suction pressures should operate at their 5- Compare the normal operating pressures to the pres­ normal start‐up ranges. sures obtained from the gauges.
  • Page 27 TABLE 10 GAS PIPING COMPONENTS KGA150 NORMAL OPERATING PRESSURES REFER TO INSTALLATION INSTRUCTIONS CIRCUIT 1 CIRCUIT 2 Outdoor Dis­ Dis­ VALVE Coil GROUND Suction Suction charge charge JOINT UNION Entering +10 psig +5 psig +10 psig +5 psig Air Temp 655 F MANUAL MAIN 755 F...
  • Page 28 On multiple unit installations, each unit should be checked TABLE 12 separately while operating at maximum rate, beginning with Gas Manifold Pressure the one closest to the supply gas main and progressing to in. w.g. (kPa) Altitude - ft. (m) the one furthest from the main.
  • Page 29: Section Iv- Charging

    8-Flame Sensing WARNING Flame current is an electrical current which passes from the ignition control through the sensor electrode during unit op­ Product contains fiberglass wool. Disturbing the insulation in this product during eration. The current passes from the sensor through the installation, maintenance, or repair will expose you flame to the ground electrode (located on the flame elec­...
  • Page 30: Top View

    D-Burners 1- Shut off power supply and gas to unit. Periodically examine burner flames for proper appearance 2- Disconnect pressure switch air tubing from combustion air inducer port. during the heating season. Before each heating season, ex­ amine the burners for any deposits or blockage which may 3- Remove and retain screws securing combustion air in­...
  • Page 31 A-LARMF Mounting Frames FIBERGLASS INSULATION (Furnished) When installing units on a combustible surface for downflow discharge applications, the Lennox C1CURB roof mounting COUNTER FLASHING frame is used. The roof mounting frames are recommended (Field Supplied) NAILER STRIP in all other applications but not required. If the KGA units are (Furnished) not installed on a flat (roof) surface, they MUST be support­...
  • Page 32: Manual Outdoor Air Damper

    LAOAD(M) MOTORIZED OUTDOOR AIR DAMPER MOTORIZED DAMPER COVER PANEL HORIZONTAL SUPPLY AIR OPENING COMPRESSOR HORIZONTAL SECTION RETURN AIR OPENING LOWER PANEL MANUAL OUTDOOR AIR DAMPER COVER PANEL MANUAL DAMPER HORIZONTAL SUPPLY AIR OPENING COMPRESSOR HORIZONTAL SECTION RETURN AIR OPENING LOWER PANEL FIGURE 25 Page 32...
  • Page 33 ECONOMIZER ECONOMIZER ACCESSORY PANEL MULLION DIVIDER PANEL (Attach with two provided screws) BOTTOM OF COMPRESSOR SECTION FLANGED RETURN AIR OPENING FIGURE 26 E-K1ECON20B Economizer MIXED AIR SENSOR (R1) LOCATION (Field- or Factory-Installed) Economizers use outdoor air for free cooling when temper­ ature and/or humidity is suitable.
  • Page 34 A6 Enthalpy Control LEDs TABLE 15 ENTHALPY CONTROL SETPOINTS A steady green Free Cool LED indicates that outdoor air is Control Setting Free Cooling Setpoint At 50% RH suitable for free cooling. ° ° F (23 When an optional IAQ sensor is installed, a steady green °...
  • Page 35 CHART 1 CALCULATE MINIMUM FRESH AIR PERCENTAGE MIXED AND RETURN AIR TEMPERATURE OUTDOOR AIR TEMPERATURE DCV Set and Max Settings Outdoor Air Not Suitable: During the unoccupied time period dampers are closed. Adjust settings when an optional IAQ sensor is installed. During the occupied time period a cooling demand will open The DCV SET potentiometer is factory-set at approxi­...
  • Page 36: Damper Motor

    The dampers must be used any time an economizer and a od and remains closed during the unoccupied period. power exhaust fan is applied to KGA series units. Manual damper assembly is set at installation and re­ Gravity exhaust dampers allow exhaust air to be dis­...
  • Page 37 Three different types of control systems may be used with 1- Transformer (T20) is a 600V to 120/240V step-down trans­ the KGA series units. All thermostat wiring is connected to former mounted in the blower compartment. TB1 located in the control area. Each thermostat has addi­...
  • Page 38 2- Electronic thermostat K-LP / Propane Kit Any two stage heat / two stage cool electronic ther­ KGA092/150 units require a natural to LP /propane kit. mostat may be used. The kit includes one LP spring conversion kit, up to eleven burner orifices and three stickers.
  • Page 39 SWITCH, LIMIT LOW COMPRESSOR 2 COOLING SWITCH, OVERLOAD RELAY BLOWER MOTOR SWITCH, DISCONNECT SWITCH, FREEZESTAT COMP 1 SWITCH, FREEZESTAT COMP 2 REV. 0.0 SWITCH, LOW PRESS, LOW AMBIENT KIT COMP 2 SWITCH, OVERFLOW S149 TRANSFORMER, CONTROL Lennox Commercial Page 39...
  • Page 40 KGA092/150 Sequence of Operation Power: the thermostat. G energizes blower. 24VAC is routed through TB1 passing N.C. freezestat S49 and optional 1- Line voltage from unit disconnect energizes trans­ N.C. high pressure switch S4. Compressor contactor former T1. T1 provides 24VAC power to terminal strip K1 is energized.
  • Page 41 GAS HEAT FOR KGA092/150 UNITS 10 12 Page 41...
  • Page 42: Gas Heat Sequence Of Operation

    GAS HEAT SEQUENCE OF OPERATION First Stage Heat: End of Second Stage Heat: 1- The thermostat initiates W1 heating demand. 9- Heating demand is satisfied. Terminal W2 (high fire) is de-energized. 2- 24VAC is routed from TB1 to ignition control A3 through P2.
  • Page 43: Operation

    ACCESSORIES ECONOMIZER ONLY TOUCHSCREEN THERMOSTAT REV. 2.0 Lennox Commercial POWER: 1- Terminal strip TB1 energizes thermostat components with 24VAC. OPERATION: 2- TB1 receives data from the electronic thermostat A2 (Y1, Y2, W1, W2, G, OCP). The 24VAC signal from TB1 ener­...
  • Page 44: Sequence Of Operation

    ECONOMIZER SEQUENCE OF OPERATION POWER: 1- Terminal strip TB1 energizes the economizer components with 24VAC. OPERATION: 2- Enthalpy sensor A7 and A62 (if differential enthalpy is used) communicates to the economizer control module A6 when to power the damper motor B7. 3- Economizer control module A6 supplies B7 with 0 - 10 VDC to control the positioning of economizer.

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