Carrier 50KC04-06 Service And Maintenance Instructions

26Not all available heater modules may be used in every unit.Use only those heater modules that are UL listed for use in aspecific size unit. Refer to the label on the unit cabinet regard-ing approved heaters.Unit heaters are marked with heater model numbers. But heat-ers are ordered as and shipped in cartons marked with a corre-sponding heater sales package part number. See Table 4 forcorrelation between heater model number and sales packagepart number.NOTE: The value in position 9 of the part number differs betweenthe sales package part number (value is 1) and a bare heater modelnumber (value is 0).Fig. 35 — Typical Component LocationFig. 36 — Typical Module InstallationSingle Point Boxes and Supplementary FusesWhen the unit MOCP device value exceeds 60-A, unit-mount-ed supplementary fuses are required for each heater circuit.These fuses are included in accessory single point boxes, withpower distribution and fuse blocks. The single point box willbe installed directly under the unit control box, just to the leftof the partition separating the indoor section (with electricheaters) from the outdoor section. The single point box has ahinged access cover. See Fig. 37.Fig. 37 — Typical Single Point InstallationOn 50KC units, all fuses are 60-A. Single point boxes contain-ing fuses for 208/230-v applications use UL Class RK5 250-vfuses (Bussman FRNR 60 or Shawmut TR 60R). Single pointboxes for 460-v and 575-v applications use UL Class T 600-Vfuses (Bussman JJS 60 or Shawmut A6T 60). (Note that allheaters are qualified for use with a 60-A fuse, regardless of ac-tual heater ampacity, so only 60-A fuses are necessary.)Unit heater applications not requiring supplemental fuses re-quire a special single point box without any fuses. Connectpower supply conductors to heater conductors and field-sup-plied base unit power tap leads (see text below regarding“Completing Heater Installation”) inside the empty singlepoint box using UL-approved connectors.SAFETY DEVICESElectric heater applications use a combination of line-break/auto-reset limit switches and a pilot-circuit/manual reset limitswitch to protect the unit against over-temperature situations.Line-break/auto-reset limit switches are mounted on the baseplate of each heater module. See Fig. 38. These are accessedthrough the indoor access panel. Remove the switch by remov-ing two screws into the base plate and extracting the existingswitch.Pilot-circuit/manual reset limit switch is located in the sideplate of the indoor (supply) fan housing. See Fig. 35.Table 4 — Heater Model NumberBare heatermodel number C R H E A T E R 0 0 1 A 0 0Heater Sale Package PNOIncludes:Bare HeaterCarton and packing materialsInstallation sheetC R H E A T E R 1 0 1 A 0 0DISCONNECTMOUNTINGLOCATIONEMT OR RIGID CONDUIT(FIELD-SUPPLIED) SINGLEPOINT BOX CENTERPOSTHEATERCOVERSHEATERMOUNTINGBRACKETHEATERMODULE(LOCATION 2)HEATERMODULE(LOCATION 1)SINGLE POINTBOXMOUNTINGSCREWBRACKET ANDCONDUITDRIP BOOTMAINCONTROLBOXCONTROL WIRE TERMINAL BLOCKMANUAL RESETLIMIT SWITCHTRACKFLANGEALLIED PAMODEL NO.ERIAL NO.CORP.OD22.23123ISTED AIRNDITIONINGUIP ACCESS346N .P / N 2- 5610-4 REV11 1321 23CONTROLBOXBUSHINGSINGLEPOINT BOXMOUNTINGSCREWSFOAMBUSHINGDRIP BOOTBRACKETMOUNTINGSCREWSHEATERRELAYSPOWERWIRESHEATERMOUNTINGSCREWS