Friedrich 000 BTU'S, 9 service manual Compressor Checks

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COMPRESSOR CHECKS

WARNING

ELECTRIC SHOCK HAZARD

Turn off electric power before service or installation. Extreme care must be used, if it becomes necessary to work on equipment with power applied.

Failure to do so could result in serious injury or death.

Locked Rotor Voltage (L.R.V.) Test

Locked rotor voltage (L.R.V.) is the actual voltage available at the compressor under a stalled condition.

Single Phase Connections

Disconnect power from unit. Using a voltmeter, attach one lead of the meter to the run “R” terminal on the compressor and the other lead to the common “C” terminal of the com- pressor. Restore power to unit.

Determine L.R.V.

Start the compressor with the volt meter attached; then stop the unit. Attempt to restart the compressor within a couple of seconds and immediately read the voltage on the meter. The compressor under these conditions will not start and will usually kick out on overload within a few seconds since the pressures in the system will not have had time to equalize. Voltage should be at or above minimum voltage of 197 VAC, as specified on the rating plate. If less than minimum, check for cause of inadequate power supply; i.e., incorrect wire size, loose electrical connections, etc.

Amperage (L.R.A.) Test

The running amperage of the compressor is the most impor- tant of these readings. A running amperage higher than that indicated in the performance data indicates that a problem exists mechanically or electrically.

Single Phase Running and L.R.A. Test

NOTE: Consult the specification and performance section for running amperage. The L.R.A. can also be found on the rating plate.

Select the proper amperage scale and clamp the meter probe around the wire to the “C” terminal of the compressor.

Turn on the unit and read the running amperage on the me- ter. If the compressor does not start, the reading will indicate the locked rotor amperage (L.R.A.).

Overloads

The compressor is equipped with an external or internal overload which senses both motor amperage and wind- ing temperature. High motor temperature or amperage heats the overload causing it to open, breaking the com- mon circuit within the compressor.

Heat generated within the compressor shell, usually due to recycling of the motor, is slow to dissipate. It may take anywhere from a few minutes to several hours for the overload to reset.

Checking the Overload

WARNING

ELECTRIC SHOCK HAZARD

Turn off electric power before service or installation. Extreme care must be used, if it becomes necessary to work on equipment with power applied.

Failure to do so could result in serious injury or death.

WARNING

BURN HAZARD

Certain unit components operate at temperatures hot enough to cause burns.

Proper safety procedures must be followed, and proper protective clothing must be worn.

Failure to follow this warning could result in moderate to serious injury.

External Overload VPAK 9, 12, 18 K Btus

With power off, remove the leads from compressor termi- nals. If the compressor is hot, allow the overload to cool before starting check. Using an ohmmeter, test continu- ity across the terminals of the external overload. If you do not have continuity; this indicates that the overload is open and must be replaced.

Internal Overload VPAK 24 K Btus

The overload is embedded in the motor windings to sense the winding temperature and/or current draw. The overload is connected in series with the common motor terminal.

1.With no power to unit, remove the leads from the com- pressor terminals. Allow motor to cool.

2.Using an ohmmeter, test continuity between terminals C-S and C-R. If no continuity, the compressor overload is open and the compressor must be replaced.

Internal Overload

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Contents Single Package Vertical Air Conditioning System Technical Support Contact Information Table of Contents Important Safety Information Your safety and the safety of others are very importantRefrigeration System Hazards Introduction Property Damage HazardsSerial Number Identification Guide Chassis Specifications Electric Heat DataExtended Cooling Performance VEA Extended Cooling PerformanceVEA/VHA09-24 VEA Extended Cooling Performance Electrical Requirements Electric Shock HazardRemote Thermostat and Low Voltage Control Connections RT5 Two speed fan RT4 One speed fanThermostat Connections Electronic Control Board Features Quiet Start/StopElectronic Control Configuration Electronic control error codes diagnostics and test mode DiagnosticsTest Mode Power On and Off Features on the Electronic Control Cool mode control features for cool with electric heat units Compressor operation depends on t-stat settings Component description / A-Series specifications VERT-I-PAK Single Packaged Vertical AIR ConditionersExternal Static Pressure Indoor Airflow Data Components Testing CapacitorsCapacitor Check with Capacitor Analyzer Capacitor ConnectionsComponents Testing Heater Elements and Limit SWITCHES’ SpecificationsDrain PAN Valve Refrigeration Assembly Refrigeration Sequence of OperationService CUT/SEVER HazardSealed Refrigeration System Repairs Equipment RequiredEquipment Must be Capable Risk of Electric ShockMethod Of Charging / Repairs Burn HazardFreeze Hazard Undercharged Refrigerant Systems Overcharged Refrigerant SystemsRestricted Refrigerant System Hermetic Components Check Metering DeviceCheck Valve Capillary Tube SystemsReversing Valve DESCRIPTION/OPERATION Testing the Coil Checking the Reversing ValveProcedure For Changing Reversing Valve Touch Test in Heating/Cooling CycleFire Hazard Explosion HazardCompressor Checks Single Phase Resistance Test Ground TestChecking Compressor Efficiency Compressor Replacement Recommended procedure for compressor replacementHigh Temperatures Rotary Compressor Special Troubleshooting and Service Routine Maintenance Coils and Base PAN Excessive Weight HazardBlower Wheel / Housing / Condenser FAN / Shroud AIR FilterRoutine Maintenance Sleeve / DrainFront Cover Condensate Disposal SystemElectrical Troubleshooting Chart Cooling 9K BTU, 12K BTU, & 18K BTUElectrical Troubleshooting Chart Cooling 24K BTU Circuit Breakers areElectrical Troubleshooting Chart Heat Pump Heat Pump ModeTroubleshooting Chart Cooling Troubleshooting Chart HeatingVEA 09/12/18 with 2.5 KW, 3.4 KW or 5KW Electric HeatVHA 09/12/18 with 2.5 KW, 3.4 KW or 5KW Cool with Electric Heat Heat Pump with Electric Heat Cool with Electric Heat Heat Pump with Electric Heat Outdoor Coil Return Air Indoor Coil Accessories Wall PlenumDrain PAN Friedrich Air Conditioning Company Technical Support Contact Information Friedrich AIR Conditioning CO