Carrier 48EZ(N) - A Installation Instructions Manual

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Contents

14POWERSUPPLYFIELD-SUPPLIEDFUSED DISCONNECTHIGH VOLTAGEPOWER LEADS(SEE UNIT WIRINGLABEL)EQUIP GRCONTROL BOXSPLICE BOXLOW-VOLTAGEPOWER LEADS(SEE UNITWIRING LABEL)WYGRCWHT(W1)YEL(Y)GRN(G)RED(R)BRN(C)THERMOSTAT(TYPICAL)OORN(O)GRA (Y2)BLU (DH) DH3-PhaseOnlyA09067Fig. 10 -- High and Control--Voltage ConnectionsBalance Point Setting--Thermidistat or HybridThermostatBALANCE POINT TEMPERATURE--The “balance point”temperature is a setting which affects the operation of the heatingmode. This is a field--selected input temperature (range 5 to 55_F)(--15 to 12_C) where the Thermidistat or dual fuel thermostat willmonitor outdoor air temperature and decide whether to enable ordisable the heat pump. If the outdoor temperature is above the“balance point”, the heat pump will energize first to try to satisfythe indoor temperature demand. If the heat pump does not make asufficient improvement within a reasonable time period (i.e. 15minutes), then the gas furnace will come on to satisfy the indoortemperature demand. If the outdoor temperature is below the“balance point”, the heat pump will not be allowed to operate (i.e.locked out), and the gas furnace will be used to satisfy the indoortemperature. There are three separate concepts which are related toselecting the final “balance point” temperature. Read each of thefollowing carefully to determine the best “balance point” in ahybrid installation:1. Capacity Balance Temperature: This is a point where theheat pump cannot provide sufficient capacity to keep upwith the indoor temperature demand because of decliningoutdoor temperature. At or below this point, the furnace isneeded to maintain proper indoor temperature.2. Economic Balance Temperature: Above this point, the heatpump is the most cost efficient to operate, and below thispoint the furnace is the most cost efficient to operate. Thiscan be somewhat complicated to determine and it involvesknowing the cost of gas and electricity, as well as theefficiency of the furnace and heat pump. For the mosteconomical operation, the heat pump should operate abovethis temperature (assuming it has sufficient capacity) and thefurnace should operate below this temperature.3. Comfort Balance Temperature: When the heat pump isoperating below this point, the indoor supply air feelsuncomfortable (i.e. too cool). This is purely subjective andwill depend on the homeowner’s idea of comfort. Belowthis temperature the gas furnace should operate in order tosatisfy the desire for indoor comfort.Transformer ProtectionThe transformer is of the energy--limiting type. It is set to withstanda 30--sec. overload or shorted secondary condition. If an overloador short is present, correct overload condition and check for blownfuse on gas control board or Interface Fan Board. Replace fuse asrequired with correct size and rating.PRE--START--UPFIRE, EXPLOSION, ELECTRICAL SHOCK HAZARDFailure to follow this warning could result in personal injury,death or property damage.1. Follow recognized safety practices and wear protectivegoggles when checking or servicing refrigerant system.2. Do not operate compressor or provide any electric powerto unit unless compressor terminal cover is in place andsecured.3. Do not remove compressor terminal cover until allelectrical sources are disconnected and tagged.4. Relieve and recover all refrigerant from system beforetouching or disturbing anything inside terminal box ifrefrigerant leak is suspected around compressorterminals.5. Never attempt to repair soldered connection whilerefrigerant system is under pressure.6. Do not use torch to remove any component. Systemcontains oil and refrigerant under pressure.To remove a component, wear protective goggles andproceed as follows:a. Shut off electrical power to unit and install lockouttag.b. Relieve and reclaim all refrigerant from systemusing both high-- and low--pressure ports.c. Cut component connecting tubing with tubingcutter and remove component from unit.d. Carefully unsweat remaining tubing stubs whennecessary. Oil can ignite when exposed to torchflame.! WARNINGProceed as follows to inspect and prepare the unit for initialstart--up:1. Remove access panels (see Fig. 19).2. Read and follow instructions on all WARNING,CAUTION, and INFORMATION labels attached to, orshipped with, unit.3. Make the following inspections:a. Inspect for shipping and handling damages such asbroken lines, loose parts, disconnected wires, etc.b. Inspect for oil at all refrigerant tubing connections andon unit base. Detecting oil generally indicates arefrigerant leak.c. Leak test all refrigerant tubing connections usingelectronic leak detector, halide torch, or liquid--soapsolution. If a refrigerant leak is detected, see the Checkfor Refrigerant Leaks section.d. Inspect all field-- and factory--wiring connections. Besure that connections are completed and tight.e. Ensure wires do not touch refrigerant tubing or sharpsheet metal edges.f. Inspect coil fins. If damaged during shipping andhandling, carefully straighten fins with a fin comb.FIRE, EXPLOSION HAZARDFailure to follow this warning could result in personal injury,death or property damage.Do not purge gas supply into the combustion chamber. Do notuse a match or other open flame to check for gas leaks. Use acommercially available soap solution made specifically forthe detection of leaks to check all connections.! WARNING48EZ -- A