Each year, the compressor manufacturer's receive numerous field returned compressors that apparently have failed. The most important ones are: a letter code, a design letter and a service factor. A high percentage of these good compressors are single phase compressors condemned for locked rotor. See NEMA Three Phase Motor Designs for more details: See Basic of AC Motor Service Factor Rating, How To Test and Check Single phase Electric Motors, How to Test a 3 Phase Motor Windings With an Ohmmeter, How to Calculate Inverter Power Rating and Inverter Battery Backup Time, How to Measure Electric Motor Insulation Resistance, Types of Earthing Systems Used in Electrical Installations, Resistance and Reactance per km of Copper and Aluminium cables, How to Install and Wire a Photocell Switch in a Lighting Installation. It looks like the motor is wired for 460 Volts now. A significant number of these, believe it or not, are still in good working order. Continuous Current (A): 20.0Locked Rotor Current (A): 93.0Crankcase Heater: Not IncludedRefrigerant Oil: POESuction Line Location: 2Suction Line Height (in. This also holds true for the RLA. Q: Do open winding readings mean a defective compressor? This is a 3 phase induction motor, it has superior starting torque. Need a Quote? With the SF at 1.15 you can do moderate short duration overloads like starting a compressor. The input terminals correspond to the motor's phase and neutral points. Features Scroll Compressor, Displacement (in^3/Rev) 8.72, Displacement (ft^3/hr) 1059.85, 80 MCC Amps, 3500 RPM High Locked Rotor Amps 300 Locked Rotor Amps 300 Mass Flow 2290 lbs./hr.,1930 lbs./hr. A: No, not necessarily. (A/C is running for special equipment, not to cool air temp of room) The unit went into locked rotor, and was humming when the EC got to the site. This one shows the reason the Copeland scroll compressor failed. Thorough diagnostics are required to confirm a failed compressor. Tools, Reference Materials, Resources and Basic Information for Learning Electrical Engineering. ): 11-3/4Suct Copeland ZR61K3E-TF5-950 - Scroll Compressor, 62,000 BTUH, R22, 208-230V, 3 Phase | Gemaire Distributors Simply confirming a high amp draw on the common winding is not enough. Reference: NEMA Standards MG 1-12.35. The letter code consists of letters from A to V. Compressor is sealed unit pumping R-22. Contact Joliet Technologies to get the answers. Go up one extra CNC phase converter size for any motors that are foreign, high efficiency, or have locked rotor currents that are greater than 6 times full load current. Chapter 3. In this post we will discuss the difference between the locked current and starting current of induction motor. On a 3 phase compressor for a package air conditioning unit, if you lose 1 leg of power will the compressor motor burn itself out? 3 Compressor Protector Tripped Detect using current 4 Locked Rotor Lockout on 4th successive locked rotor trip 5 Demand Signal Loss Capacity Req < 0.5VDC, shut down 6 Discharge Thermistor Fault Wires broken, Cf %Capacity forced to max 50% 7 Future 8 Welded Contactor Detect using current 9 Low Supply Voltage Supply voltage < 19VAC, shut down A NEMA motor nameplate has some supplementary information. Even hitting the side of it with a tool/foot on start-up worked once, and this isn't a guarantee it will last long after either. These values are maximum allowable of the motor of the compressor. When you experience excessive LRA, the cause needs to be found and repaired, otherwise compressor damage is likely. Ive "un-stuck" (got going) a few 3 phase compressors by reversing any 2 legs of power going to it. 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