Carrier PERFORMANCE 50VT-A Installation Instructions Manual

Also see for COMFORT 50VT-A: Owner's information manual Owner's information manual Installation instructions

Contents

Carrier PERFORMANCE 50VT-A Installation Instructions Manual Manual pdf 17 page image

17PRE--START--UPFIRE, EXPLOSION, ELECTRICAL SHOCK ANDENVIRONMENTAL 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. Relieve and recover all refrigerant from system beforetouching or disturbing compressor plug if refrigerantleak is suspected around compressor terminals.3. Do not remove compressor plug until all electricalsources are disconnected and tagged.4. Never attempt to repair soldered connection whilerefrigerant system is under pressure.5. 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.! WARNINGUse the Start--Up Checklist supplied at the end of this book andproceed as follows to inspect and prepare the unit for initialstart--up:1. Remove all access panels (see Fig. 21).2. Read and follow instructions on all DANGER, 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. Leak--test all refrigerant tubingconnections using electronic leak detector, orliquid--soap solution. If a refrigerant leak is detected, seefollowing Check for Refrigerant Leaks section.c. Inspect all field and factory--wiring connections. Be surethat connections are completed and tight. Ensure wiresdo not touch refrigerant tubing or sharp sheet metaledges.d. Inspect coil fins. If damaged during shipping andhandling, carefully straighten fins with a fin comb.4. Verify the following conditions:a. Make sure that outdoor--fan blade is correctly positionedin fan orifice.b. Make sure that air filter(s) is in place.c. Make sure that condensate drain pan and trap are filledwith water to ensure proper drainage.d. Make sure that all tools and miscellaneous loose partshave been removed.5. Each unit system has 2 Schrader--type ports, one low--sideSchrader fitting located on the suction line, and onehigh--side Schrader fitting located on the compressordischarge line. Be sure that caps on the ports are tight.START--UPChecking Cooling and Heating Control OperationStart and check the unit for proper control operation as follows:(1.) Place room thermostat SYSTEM switch or MODEcontrol in OFF position. Observe that blowermotor starts when FAN mode is placed in FAN ONposition and shuts down when FAN MODE switchis placed in AUTO position.(2.) Thermostat:When the room temperature rises to a point that isslightly above the cooling control setting of thethermostat, the thermostat completes the circuitbetween thermostat terminal R to terminals Y, Oand G.These completed circuits through thethermostat connect contactor coil (C) (through unitwire Y) and Indoor Fan board (through unit wireG) across the 24--v. secondary of transformer(TRAN).(3.) Place system switch or MODE control in HEATposition. Set control above room temperature.Observe that compressor, outdoor fan, and indoorblower motors start. Observe that heating cycleshuts down when control setting is satisfied.(4.) When using an automatic changeover roomthermostat place both SYSTEM or MODE controland FAN mode switches in AUTO positions.Observe that unit operates in Cooling mode whentemperature control is set to “call for Cooling”(below room temperature), and unit operates inHeating mode when temperature control is set to“call for Heating” (above room temperature).NOTE: Once the compressor has started and then has stopped, itshould not be started again until 5 minutes have elapsed. Thedefrost board has a built--in 5 minute delay between cycles. The 5minute compressor delay also applies to heat pump heating mode.Step 1 — Check for Refrigerant LeaksProceed as follows to locate and repair a refrigerant leak and tocharge the unit:1. Locate leak and make sure that refrigerant system pressurehas been relieved and reclaimed from both high-- andlow--pressure ports.2. Repair leak following Refrigerant Service procedures.NOTE: Install a bi--flow filter drier whenever the system has beenopened for repair.3. Add a small charge of R--410A refrigerant vapor to systemand leak--test unit.4. Recover refrigerant from refrigerant system and evacuate to500 microns if no additional leaks are not found.5. Charge unit with Puron (R--410A) refrigerant, using anelectronic scale. Refer to unit rating plate for requiredcharge.Step 2 — Start--Up AdjustmentsComplete the required procedures given in the Pre--Start--Upsection before starting the unit. Do not jumper any safety deviceswhen operating the unit. Do not operate the unit in Cooling modewhen the outdoor temperature is below 40_F (4_C) (unlessaccessory low--ambient kit is installed).IMPORTANT: Three--phase, scroll compressors are directionoriented. Unit must be checked to ensure proper compressor3--phase power lead orientation. If not corrected within 5 minutes,the internal protector will shut off the compressor. The 3--phasepower leads to the unit must be reversed to correct rotation. When50VT-- A