How to find out the actual ohmic resistance of a winding of a hermetic compressor?
Measurement of the ohmic field resistance of auxiliary (starting) and mainly (running) coils must be made with the compressor switched off without the electrical components and at an ambient temperature stabilized for 12 hours at 25 ° C (resistance in the coils varies with room temperature : The higher the resistance reading obtained). Under these conditions, the resistance of the coils is measured directly at the airtight terminal of the compressor with an ohmmeter; For the auxiliary coil (starting) the measurement is made between the terminals C - S (Common - Start) of the hermetic terminal and for the main coil between the terminals C - R (Common - Run) with hermetic terminal. The specification of the resistance of the Sicom compressor coils at 25 ° C has a tolerance of plus or minus 7%. The resistance of the auxiliary coil is connected to the start of the compressor, not to its cooling capacity. A compressor with greater than the specified auxiliary coil resistance (eg, 8 to 10%) may cause a decrease in the starting torque of the compressor, thereby impairing its starting. If the coil resistance is out of specification, there may be a decrease in the rotation of the compressor and consequent loss of cooling capacity that can be reached by the compressor.