Motor Start Capacitors

Motor Start Capacitors

Rahshad Electric Company has a long history in producing various types of motor and lighting capacitors and now based on the needs of the Iranian industry, the electrolytic motor start capacitor has been added to its product portfolio. Introducing new products in accordance with the latest standards related to the product and system in order to grow and flourish of national determination and meeting the needs of various industries is a clear proof of the company’s managerial, production and technical capabilities of the company.

Applications

Electrolytic motor start capacitors with series connection are used in single-phase induction motors to increase the initial starting torque power. It is necessary to compensate for a large part of high reactive power in less than a second up to maximum a few seconds and make it easy to start. For soft starting of single-phase induction motors, the initial starting torque must be increased and the inrush current reduced.

By installing two types of capacitors, one which is a starting switch capacitor and the other is a motor run capacitor, the above advantage is achieved. The starting switch capacitor, often with a capacitance of about three times that of a permanent operating capacitor must be removed from the circuit after the motor reaches the nominal RPM, and the permanent working capacitor is still in the circuit by connecting in series to the auxiliary coil. In order to reduce the size of the capacitor and create high values ​​of capacitance, such capacitors are used.

The capacitive element is made of aluminum foil and impregnated paper layers inside the liquid electrolyte. The capacitor body is made of heat-resistant plastic materials. Some of the applications of electrolytic motor start capacitors are:

• Assisting in starting low voltage compressors including refrigerator and air conditioner compressors
• Assisting in starting the HP motors, such as ¾ HP (horse power) and industrial lift engines
• Used in various types of heavy agricultural machinery, mills, residential and commercial cooling and heating systems

Advantages of Using Rahshad Electric Motor Start Capacitors

1. Keeping international standard IEC 60252-2
2. Diverse range of capacity with the smallest possible dimensions
3. Existence of safety valve and high safety sealing
4. Proper quality and reasonable price

Important Points

• Electrolytic capacitors which are stored for a long time may be broken and lose their quality. The operation of electrolytic capacitors is considered for two years from the date of production. After this time, the capacitors must be inspected before starting to work. If there is no test tool for the customer, the voltage can be repeated for 2 or 3 seconds and three times, but not more than 10 seconds in total.
• Capacitance and power factor are measured using the following circuit.

V: Voltmeter

I: Ammeter

W: Wattmeter designed for operation with accuracy

C: Capacitor under test

After applying the voltage, the voltage after 2 seconds, the current after 3 seconds and the power after 4 seconds should be read. Nominal voltage should not be applied for more than 4 seconds. The capacitance is calculated based on the following formula:

F:Frequency (HZ)

C: Capacitance (μF)

I: Effective current (A)

U: Effective test voltage (V)

The power factor should be calculated based on the abovementioned at the same time from the following formula

P: Effective power factor (W)

I: Effective current (A)

U: Effective voltage (V)