General Information
A capacitor is an energy-storing device that stores voltage or builds it up until the call for it to be released is present. The energy capacitance of an electric capacitor is measured in the form of micro-farads ㎌. Inside, a capacitor has two plates separated by a material known as a dielectric or insulator. These insulators include mica, ceramic, porcelain, mylar, Teflon, glass, or rubber. Capacitors will also limit current.
The capacitors generally defined as motor capacitors are used for the start-up and running of single-phase induction 2 and 3 windings motors.
The capacitance of these capacitors (permanent connection) must be carefully established to avoid possible overheating of the auxiliary winding.
Difference between start and run capacitors
Run Capacitors
- it is used to maintain a charge
- uses a charge in the dielectric to boost the current which provides power to the motor
- the value, or rating, of the run capacitor must be accurate
- if the value of the capacitor is too high, the phase shift will be less than perfect and the winding current will be too high
- if the value of the capacitor is too low, the phase shift will be higher and the winding current will be too low
- the capacitor has to be ideal, otherwise, the motor could overheat and the true torque will not be enough to drive current
- stays connected in the circuit all the time
- AC units have dual run capacitors, one provides power to the fan motor, and the other sends power to the compressor
Start Capacitors
- found in the circuit of start windings when the motor is starting
- contains a higher capacitance than a run capacitor
- provides an immediate electrical push to get the motor rotation started
- without a start capacitor, when the voltage is applied, the motor would just hum
- creates current to voltage lag in the separate start windings of the motor
- the current builds up slowly and the armature has an opportunity to begin rotating with the field of current
- as the motor picks up speed, the start capacitor is disconnected by a centrifugal switch
Construction peculiarities
For the construction of these capacitors, a polypropylene film dielectric is used, metalized in a vacuum, with self-healing that allows the obtaining of capacitive units with very low losses and reduced overall dimensions. These elements are subsequently encapsulated in a plastic case and then incorporated into the resin.
Warnings
Improper use of the capacitor such as, for example, applications that involve exceeding the capacities and/or characteristics reported on a given capacitor, can cause an irreversible breakdown and/or breakage that can occur with a deterioration such as loss of capacitance, increase of power factor and permanent circuit interruption.
RoHS Directive
All capacitors on this website are in line with the European directive 2002 / 95 / EC already known as the RoHS directive.
Protection degree according to IEC EN 60529
| 1st letter | Degree of protection against persons and foreign bodies | 2nd letter | Degree of protection against water |
|---|---|---|---|
| 0 | Non-protected | 0 | Non-protected |
| 1 | Protected against solid objects greater than 50 mm | 1 | Protected against dripping water |
| 2 | Protected against solid objects greater than 12 mm | 2 | Protected against water when tilted up to 15℃ |
| 3 | Protected against solid objects greater than 2,5 mm | 3 | Protected against spraying water |
| 4 | Protected against solid objects greater than 1 mm | 4 | Protected against splashing water |
| 5 | Dust protected | 5 | Protected against water jets |
| 6 | Totally dust protected | 6 | Protected against water waves |
Determination of the necessary capacitor value to connect a three-phase motor to a single-phase motor
Technical Details
Technical Details for MECO Capacitors
| Parameter | Value |
|---|---|
| Capacitance tolerance | ±5% |
| Rated voltage | 450 Vac |
| Rated frequency | 50 / 60 Hz |
| Loss angle | tan∂ ≤20 x 10-4 (Vn - 50Hz) |
| Operating temperature | -25℃ +85℃ |
| Climatic category | 25/85/21 |
| Test voltage | between terminals: 2 Vn x 2” between terminals and case: 3000 Vac x 2” |
| Insulation resistance | 104 MΩ • ㎌ |
| Approvals | IMQ |
| Reference standard | EN60252-1 |
| Application class | B=10.000 h |
| Protection degree | IP00 |
| Security class | S0 |
| Case and cover | self-extinguishing plastic material grade V2 according to UL 94 |
| Storage temperature | -40℃ +85℃ |
Capacitor connection
Capacitor life depending on temperature
Capacitor life depending on voltage
