Carrier 48EN Installation, Operation And Maintenance Instructions

Contents

Carrier 48EN Installation, Operation And Maintenance Instructions Manual pdf 12 page image

Packaged rooftop unitswith integrated gas burner12Main door switchBy using a mechanical device,it impedes access to the electricpanel when the unit is withvoltage.High pressure pressostatConnected to the compressor discharge, it willstop its operation when the pressure at that pointreaches the setpoint. It disconnects at 42 bar andit is automatically reactivated.Low pressure pressostatWhen connected to the compressor suction, itwill stop its operation when the pressure at thatpoint goes down below the tare value (caused byobstructions in the circuit, excessive dirt in the filters, fan stop or iceformation in the evaporator).It disconnects at 2 bar and it is automatically reactivated.Safeties at the compressorThe scroll type compressor that these units as standard have thefollowing safeties:- Non-return valve built into the compressor.- Klixon in the compressor, which stops the operation of the motorwhen there is excessive heating.Condensation and evaporation pressure controlThis safety element, integrated in the control, enables managing theoutdoor fans when the units are working in COOLING mode with lowoutdoor temperatures (condensation control) or in HEATING mode withhigh outdoor temperatures (evaporation control).This aids the unit's operation in all the stations.Smoke detector (optional)This smoke detection station uses a LED to indicate the installationstatus and if the probe detects the presence of smoke in the installationit stops the operation of the unit. The station is installed in the factoryin the auxiliary electric panel.Smoke detecting stationSmoke detecting probeClogged fi lter detector (optional)Differential pressostat for indication of maintenance to filters. Automaticreactivation. It is installed in the auxiliary electric panel.Anti-fi re safety deviceThis safety device, integrated in the control, shuts down the unit if theprobe located in the return detects an air inlet temperature above60ºC. The unit will not return to operation until this temperature dropsunder 40ºC.Control of air flowDifferential pressostat that measures the flow variation in the air outlet.This allows the detection of fan belt breakages, since the fan relay onlydetects operating faults that have arisen in the motor. This pressostatis installed in the factory in the auxiliary electric panel.Protection of the electric panel (optional)Anti-freeze protection for low outdoor temperatures with electric heater.This safety device is compulsory when the outdoor conditions guaranteean air inlet temperature to the burner which is less than -15ºC.Air quality probe (optional)This probe is for installation in the environment or in duct to enablemeasuring CO 2 and/or volatile compounds.This probe is to be connected by the client. The clamps on the terminalboard on the main panel used for the connection are indicated on thewiring diagram provided with the unit.This probe is supplied inside the main electric panel.Automatic switch in the control circuitMagnetothermal switch that protects the operation circuit againstcontinuous surges as well as against high currents of short duration(short circuits).Defrost controlThis safety element is intended to eliminate ice which could accumulatein the outdoor coil when the unit is working in the heating CYCLE.Defrosting is carried out by the control depending on the valuemeasured by the sensors on the outdoor coils and the time set betweendefrosting operations.Magnetothermals for line protectionThey are located at the beginning of the power lines of the compressorand motorised fans to protect them.Safety devices in the 48EN/EH unit