Carrier 58MCA Installation, Start-up, And Operating Instructions Manual

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Carrier 58MCA Installation, Start-up, And Operating Instructions Manual Manual pdf 19 page image

Use a separate, fused branch electrical circuit containing a properlysized fuse or circuit breaker for this furnace. See Table 4 for wiresize and fuse specifications. A disconnecting means must belocated within sight from and readily accessible to furnace.NOTE: Proper polarity must be maintained for 115-v wiring. Ifpolarity is incorrect, control center LED status indicator light willflash rapidly and furnace will NOT operate.The cabinet MUST have an uninterrupted or unbroken groundaccording to NEC ANSI/NFPA 70-1999 and Canadian Elec-trical Code CSA C22.1 or local codes to miniize personalinjury if an electrical fault should occur. This may consist ofelectrical wire or conduit approved for electrical ground wheninstalled in accordance with existing electrical codes. Do notuse gas piping as an electrical ground. Failure to follow thiswarning could result in electrical shock, fire, or death.J-Box Relocation1. Remove 2 screws holding auxiliary J-box. (See Fig. 23.)2. Rotate J-box 180° and attach box to right side, using holesprovided.If manual disconnect switch is to be mounted on furnace,select a location where a drill or fastener will not contactelectrical or gas components.Step 2—24-v WiringMake field 24-v thermostat connections at 24-v terminal block oncontrol center. For proper cooling operation, Y wire from thermo-stat MUST be connected to Y terminal on control center, as shownin Fig. 22. The 24-v terminal board is marked for easy connectionof field wiring. (See Fig. 24.) The 24-v circuit contains a 3-amp,automotive-type fuse located on control center. (See Fig. 25.) Anyelectrical shorts of 24-v wiring during installation, service, ormaintenance may cause fuse to blow. If fuse replacement isrequired, use only a fuse of identical size (3 amp).NOTE: Use AWG No. 18 color-coded copper thermostat wire forlengths up to 100 ft. For wire lengths over 100 ft, use AWG No.16 wire.Step 3—Accessories1. Electronic Air Cleaner (EAC)Two quick-connect terminals marked EAC-1 and EAC-2 areprovided for EAC connection. (See Fig. 25.) These terminalsare energized with 115v (1.5-amp maximum) during blowermotor operation.2. Humidifier (HUM)A quick-connect terminal (HUM) and screw terminal (C OM)are provided for 24-v humidifier connection. (See Fig. 24.)HUM terminal is energized with 24-v (0.5-amp maximum)after pressure switch closes.NOTE: A field-supplied, 115-v controlled relay connected toEAC terminals may be added if humidifier operation is desiredduring blower operation.DIRECT VENTINGThe 58MCA Furnaces require a dedicated (one 58MCA furnaceonly) direct-vent system. In a direct-vent system, all air forcombustion is taken directly from outside atmosphere, and all flueproducts are discharged to outside atmosphere.Step 1—Removal of Existing Furnaces fromCommon Vent SystemsIf furnace being replaced was connected to a common vent systemwith other appliances, the following steps shall be followed witheach appliance connected to the venting system placed in opera-tion, while any other appliances connected to the venting systemare not in operation:1. Seal any unused openings in the venting system.2. Inspect the venting system for proper size and horizontal pitchas required in the NFGC or NSCNGPIC and these instruc-tions. Determine that there is no blockage or restriction,leakage, corrosion, and other deficiencies which could causean unsafe condition.3. In so far as is practical, close all building doors and windowsand all doors between the space in which the appliance(s)connected to the venting system are located and other spacesof the building. Turn on clothes dryers and any appliance notconnected to the venting system. Turn on any exhaust fans,such as range hoods and bathroom exhausts, so they shalloperate at maximum speed. Do not operate a summer exhaustfan. Close fireplace dampers.4. Follow the lighting instructions. Place the appliance beinginspected in operation. Adjust thermostat so appliance shalloperate continuously.Do not connect aluminum wire between disconnect switchand furnace. Use only copper wire.A93033COPPERWIRE ONLYELECTRICDISCONNECTSWITCHALUMINUMWIREFig. 23—Relocating J-Box A93051ALTERNATEFIELDLOCATIONFACTORYINSTALLEDLOCATION19