The A / C start capacitor is located in the compressor circuit. Sometimes it fails. Read more about the types of capacitors and their meaning.
Why do you need a starting capacitor for an air conditioner?
The windings in the motors are designed so that their magnetic poles are perpendicular to each other.
In the windings, the values of the rated currents and the number of turns, and hence the resistance, are different. However, their power is equivalent.
A capacitor called a phase-shifting capacitor is connected to them. Its function is to move the phase and rotate the magnetic field in a circle.
Two air conditioner capacitors are connected to the circuit: starting and working. The most modern models manage only the latter.
The operating condenser of the air conditioner is permanently connected to the circuit, and the starting capacitor is connected only for 3 seconds while the compressor starts. Then the relay turns it off.
Thus, the working capacitor increases the efficiency and provides the operating torque for starting the motor.
High-capacity air conditioners operate on compressors with 3-phase asynchronous motors, the design of which does not provide for the use of capacitors.
Buying an air conditioner condenser
In order to buy an air conditioner capacitor, you need to know its voltage and power.
The main task of the capacitor is to create a circular magnetic field at rated load, preventing the field from stretching into an oval shape.
The calculation formula can be found in the reference book. Although in practice the ratio is more often used:
- 75 - 80 microfarads of capacity per 1 kW of motor power;
- 450 Volt capacitor voltage for standard mains voltage.
You need to buy an air conditioner condenser of the same capacity that has already been installed by the manufacturer, since its parameters are precisely calculated at the factory.
The operation of the starting capacitors of the air conditioner is checked using a capacitance meter. Replacement is required when the difference from the nominal value is 10% or more. The capacity of the new capacitor may be slightly more or equal to the failed one, but not less.
Types of compressor starting capacitors
The starting capacitors of the air conditioner compressor are available in ratings from 25 to 100 microfarads with a step of 5 microfarads.
For outdoor units of non-inverter systems, special double starting capacitors are created.
