Lennox-international-inc 4HP18LT User Manual

506470-01 Issue 1007Save these instructions for future referenceINSTALLATION AND MAINTENANCE INSTRUCTIONS4HP18LT SeriesSplit System Heat PumpManufactu

506470-01 Issue 10073. Connect the external equalizer line to the equalizer porton the suction line and tighten to 8 ft.lbs.4. Strap the superheat s

506470-01 Issue 1007Using an Electronic Leak Detector1. Connect the high pressure hose of the manifold gaugeset to the suction valve service port. (

506470-01 Issue 10074. Open both manifold valves and start vacuum pump.5. Evacuate the line set and indoor unit to a minimum of500 microns or lower.

506470-01 Issue 1007START-UP1. Rotate fan to check for frozen bearings or binding.2. Inspect all factory and field-installed wiring for looseconnect

506470-01 Issue 10071. Connect the manifold gauge set to the service valve portsas follows (See Figure 13 above): • Low pressure gauge to suction l

506470-01 Issue 10075. Compare the subcooling value with those shown in Table7. If subcooling is greater than shown, recover somerefrigerant. If su

506470-01 Issue 1007=_Outdoor Ambient Temperature °FLiquid Line Temperature °FApproach Temperature °F°°°6. Compare the approach value with those show

506470-01 Issue 1007 Page 17Table 8L - Liquid S- SuctionValues provided above are typical pressures. Indoor unit matchup, indoor air quality equipme

506470-01 Issue 1007OPERATIONOutdoor unit and indoor blower cycle on demand from theroom thermostat. When the thermostat blower switch ismoved to the

506470-01 Issue 1007Defrost Control Timing PinsEach timing pin selection provides a different accumulatedcompressor run time period during one thermos

506470-01 Issue 1007INSTALLATIONInspection of ShipmentUpon receipt of equipment, carefully inspect it for possibleshipping damage. If damage is found,

506470-01 Issue 1007System Diagnostic Module4HP18LT units contain a diagnostic module fortroubleshouting heat pump system failures. By monitoringand

506470-01 Issue 1007Every time the module powers up, the last ALERT LED flashcode that occurred prior to shutdown is displayed for60 seconds. The mod

506470-01 Issue 1007Thermostat Demand WiringThe diagnostic module requires a thermostat demand signalto operate properly. The thermostat demand signa

506470-01 Issue 1007MAINTENANCEBefore the start of each heating and cooling season, thefollowing service checks should be performed by a qualifiedserv

506470-01 Issue 1007HOMEOWNER INFORMATIONIn order to ensure peak performance, your system must beproperly maintained. Clogged filters and blocked air

506470-01 Issue 1007Fan SwitchIn AUTO or INT (intermittent) mode, the blower operatesonly when the thermostat calls for heating or cooling. Thismode

506470-01 Issue 1007Start-Up and Performance ChecklistJob Name _____________________________ Job No. ____________ Date ___________Job Location _______

506470-01 Issue 1007 Page 27Wire DiagramDESCRIPTIONKEY COMPONENTA132 DIAGNOSTIC MODULEB1 COMPRESSORB4 MOTOR - OUTDOOR FANC12 CAPACITOR - DUALCMC1 CON

506470-01 Issue 1007 Page 28NOTES

506470-01 Issue 1007Roof MountingInstall unit at a minimum of 6” above surface of the roof toavoid ice buildup around the unit. Locate the unit above

506470-01 Issue 10071. Install line voltage power supply to unit from a properlysized disconnect switch. Any excess high voltage fieldwiring should b

506470-01 Issue 1007PlacementBe aware that some localities are adopting sound ordinancesbased on how noisy the unit is at the neighbor’s home, notat t

506470-01 Issue 10076. Braze the line set to the service valve. Quench the jointswith water or a wet cloth to prevent heat damage to thevalve core a

506470-01 Issue 1007Figure 8Page 7Figure 7AnchoredHeavy NylonWire TieWallStudMetal SleeveVapor Line Wrappedin Armaflex–Liquid LineWallStudAutomotiveM

506470-01 Issue 1007Flushing Existing Line Set and Indoor CoilThis procedure should not be performed on systemswhich contain contaminants, such as com

506470-01 Issue 10074. Remover the existing R-22 refrigerant flow control orificeor thermal expansion valve before continuing with flushingprocedures