Carrier 48TCA04---A12 Service And Maintenance Instructions

15breaker requirements and disconnect switch size andlocation. Route 125--v power supply conductors into thebottom of the utility box containing the duplex receptacle.Unit--powered type: A unit--mounted transformer isfactory--installed to stepdown the main power supplyvoltage to the unit to 115--v at the duplex receptacle. Thisoption also includes a manual switch with fuse, located ina utility box and mounted on a bracket behind theconvenience outlet; access is through the unit’s controlbox access panel. See Fig. 14.The primary leads to the convenience outlet transformerare not factory--connected. Selection of primary powersource is a customer--option. If local codes permit, thetransformer primary leads can be connected at theline--side terminals on a unit--mounted non--fuseddisconnect or HACR breaker switch; this will provideservice power to the unit when the unit disconnect switchor HACR switch is open. Other connection methods willresult in the convenience outlet circuit being de--energizedwhen the unit disconnect or HACR switch is open. SeeFig. 15.CO8283Fig. 15 -- Powered Convenience Outlet WiringUNITVOLTAGECONNECTASPRIMARYCONNECTIONSTRANSFORMERTERMINALS208,230 240 L1: RED +YELL2: BLU + GRAH1 + H3H2 + H4460 480L1: REDSplice BLU + YELL2: GRAH1H2 + H3H4575 600 L1: REDL2: GRAH1H2Duty Cycle: The unit--powered convenience outlet has aduty cycle limitation. The transformer is intended toprovide power on an intermittent basis for service tools,lamps, etc; it is not intended to provide 15--amps loadingfor continuous duty loads (such as electric heaters forovernight use). Observe a 50% limit on circuit loadingabove 8--amps (i.e., limit loads exceeding 8--amps to 30minutes of operation every hour).Maintenance: Periodically test the GFCI receptacle bypressing the TEST button on the face of the receptacle.This should cause the internal circuit of the receptacle totrip and open the receptacle. Check for proper groundingwires and power line phasing if the GFCI receptacle doesnot trip as required. Press the RESET button to clear thetripped condition.Fuse on powered type: The factory fuse is a Bussman“Fusetron” T--15, non--renewable screw--in (Edison base)type plug fuse.Using unit--mounted convenience outlets: Units withunit--mounted convenience outlet circuits will oftenrequire that two disconnects be opened to de--energize allpower to the unit. Treat all units as electrically energizeduntil the convenience outlet power is also checked andde--energization is confirmed. Observe National ElectricalCode Article 210, Branch Circuits, for use of convenienceoutlets.SMOKE DETECTORSSmoke detectors are available as factory--installed optionson 48TC models. Smoke detectors may be specified forSupply Air only or for Return Air without or witheconomizer or in combination of Supply Air and ReturnAir. Return Air smoke detectors are arranged for verticalreturn configurations only. All components necessary foroperation are factory--provided and mounted. The unit isfactory--configured for immediate smoke detectorshutdown operation; additional wiring or modifications tounit terminal board may be necessary to complete the unitand smoke detector configuration to meet projectrequirements.SystemThe smoke detector system consists of a four--wirecontroller and one or two sensors. Its primary function isto shut down the rooftop unit in order to prevent smokefrom circulating throughout the building. It is not to beused as a life saving device.ControllerThe controller (see Fig. 16) includes a controller housing,a printed circuit board, and a clear plastic cover. Thecontroller can be connected to one or two compatible ductsmoke sensors. The clear plastic cover is secured to thehousing with a single captive screw for easy access to thewiring terminals. The controller has three LEDs (forPower, Trouble and Alarm) and a manual test/reset button(on the cover face).48TC