2 Wire 220vac Ceiling Fan Capacitor 6 Mfd

CAPACITOR SIZING DILEMMAS

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GOAL:

To recognize the importance of puritanical capacitor size.

OBJECTIVES:

The scholar will be able to:

1) Understand what capacitors are you bet they influence

2) Demonstrate the effect unsuitable capacitor size has on energy consumption

3) Attest the power to examination capacitors

LESSON / INFORMATION:

The simplest way to explain the mechanics of a electrical condenser would be to compare it to a barrage fire. Both store and release electricity. Capacitors are charged with electricity, past releases its stored energy at a rate of lx times per forward in a 60 cycle AC system. The size is captious to motor efficiency even as sizing of batteries is critical to a radio. A radio that requires a 9V barrage fire will non work with a 1.5V sizing battery. Thus, as the stamp battery becomes weaker the wireless will not play decently. A efferent that requires a 7.5 mfd condenser will not work with a 4.0 mfd capacitor. Much the same way, a motor bequeath not run properly with a weak electrical condenser. This is not to inculpate big is major, because a capacitor that is overlarge bathroom cause muscularity consumption to rise. In both instances, be it to a fault large OR too small, the life story of the motor will be truncated callable to overheated motor windings. Motor manufacturers pass many hours testing motor and electrical condenser combinations to get at most efficient combination. There is a uttermost of +10% tolerance in microfarad rating on replacement start capacitors, only exact run capacitors must be replaced. Potential difference rating must always beryllium the same or greater than original capacitor whether it is a start or run capacitor. Ever consult manufacturers to control correct capacitor size for the particular application.

Capacitors contain ii metal plates insulated from each separate (See Figure 1). When opened, the inside looks like two sheets of foil with wax theme in between them and rolled tight, similar to a roll of paper towel. Years ago the embrocate occupied type used PCB's as a coolant. Today most capacitors are the dry character.

Figure 1

Two basic types are old in electric motor:

1) Escape capacitors are rated in a range of 3-70 microfarad (mfd). Run capacitors are also rated by voltage categorization. The voltage classifications are 370V and 440V. Capacitors with ratings above 70 microfarad (mfd) are starting capacitors. Run capacitors are designed for continuous duty, and are energized the entire time the motor is continual. Single phase electric motors need a capacitor to perk up a second phase winding. This is wherefore sizing is and so decisive. If the wrong run electrical condenser is installed, the motor will not have got an even magnetic flux. This will lawsuit the rotor to hesitate at those spots that are uneven. This hesitation will cause the motor to become noisy, increase energy ingestion, cause operation to drop, and cause the motor to overheat.

2) Start capacitors are housed in a bleak plastic case and ingest a mfd grade as opposed to a specific mfd rating happening hunt capacitors. Start capacitors (ratings of 70 microfared or high) have threesome electric potential classifications: 125V, 250V, and 330V. Examples would be a 35 mfd at 370V run capacitor and an 88-108 mfd at 250V start capacitor. Start capacitors increase motor starting torsion and allow a motor to make up cycled off and on rapidly. Start capacitors are designed for fugitive use. Start capacitors stay energized long enough to rapidly bring the motor to 3/4 of full speed and are then taken out of the circuit.

Potential relays are also as important. Potential relays are victimised to electronically connect and disconnection to start capacitors from the motor circuit (See Figure 2). Each electrical relay has a specific voltage rating to place the set out electrical condenser in series with the start wind and a specific emf to take IT out of the circuit. Apiece rating is based along the electromagnetic field generated aside the rotation of the motor. The motor maker studies the effect of placing in and taking out the capacitor to addition start torque with as little winding twist every bit realizable. Potential relays have four ratings; (1) continuous coil voltage, (2) minimum pick-upwardly emf, (3) maximum pick-up voltage, and (4) give up voltage. A potential relay is difficult to check and should always be replaced when a start capacitor is replaced. The exact sized designed for that particular proposition motor essential beryllium reinstalled. The potential electrical relay must likewise be replaced if contacts are found to be open.

Envision 2

ACTIVITY:

Present the use of acceptable 1/2 horse power blower from a residential heater in the following exercises. During each exercise, the student should record the noise level, the speed, the temperature, and the amperage of the motor.

EXTREME Cautiousness SHOULD Represent TAKEN WHEN Playacting THIS Activenes. SEE Instructor'S NOTES!

(1) Remove the electrical condenser and hear to extend the motor. Be sure to insulate the wire ends. This will simulate an open capacitor.

(2) Run motor with correct capacitor. Block front of blower to obtain correct motor speed and amp delineate.

(3) Pint-sized the two wires that ordinarily travel to the capacitor and insulate the connection. This will simulate a shorted capacitor.

(4) Supercede the standard capacitor with one that has half the mfd rating.

(5) Substitute the touchstone capacitor with one that is double the mfd rating.

NOTE:

Before starting the exercise be sure to create proper static pressing to obtain motive plate amperage rating with even off track down capacitor.

Exercise #1	Noise Stratum	Speed	Temperature	Amperage
Exercise #2	Noise Level	Speed	Temperature	Amperage
Physical exertion #3	Make noise Spirit level	Hasten	Temperature	Amperage
Exercise #4	Noise Level	Speed	Temperature	Amperage
Exercise #5	Noise Level	Speed	Temperature	Amperage

TEACHERS NOTES

The activity connected the preceding page deals with high potential difference. Eye protection mustiness exist moth-eaten and extreme caution exercised to preclude electrocution. If not properly on-line, capacitors may explode and cause severe personal injury. It is suggested that the teacher demonstrate the natural action ahead considering allowing the student to perform it. The instructor should also check a student's work anterior to the student's test run.

REFERENCES:

Modern Refrigeration and Air Conditioning. Goodheart-Willcox Centennial State., Inc. S. Holland, Forty-nine. 1988.

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2 Wire 220vac Ceiling Fan Capacitor 6 Mfd

Source: http://www.dnr.louisiana.gov/assets/TAD/education/ECEP/hvac/d/d.htm