Induction motor capacitor application area
| Running | Starting | |
|
Application
| Induction motor circuits | Induction motor circuits |
|
Connection type
| Connection in series with electric motor auxiliary winding | In parallel with running capacitor |
|
As
| Phase-shifting element | Phase-shifting element |
|
Destination
| Allows generation of circular rotating magnetic field, necessary for electric motor startup | Allows generation of magnetic field, necessary for electric motor starting torque increase |
|
On-time
| In the process of electric motor operation | At the moment of electric motor startup |
Connection diagram
 |
In case when it’s necessary to connect three-phase electric motor to a single-phase network, there are two possible types of connection: “wye” and “delta”; in the majority of cases delta-connection is preferable. Approximate calculation for the given type of connection is made by the following formula:
Сrun=k*Iph/Unetw
where:
- k – factor depending on connection of windings
- Iph – electric motor rated phase current, A
- Unetw – single-phase network voltage, V
For wye-connection k=2800
For delta-connection k=4800
Starting capacity Сstart is being determined on the basis of starting torque. In case of electric motor startup in idle mode, starting capacity is not required
ДIn order to obtain starting torque value close to the rated one, it’s enough to have starting capacity, calculated by the following formula Сstart=(2.5-3) Сrun.