Home Electrical PFI Panel Circuit Diagram | Power Factor Improvement Diagram

PFI Panel Circuit Diagram | Power Factor Improvement Diagram

PFI Panel Circuit Diagram

Do you know about the PFI Panel Circuit Diagram? We all are familiar with PFI (power factor improvement) panel. If the value of the power factor is less than the ideal value, it helps to increase or adjust the value. We have already discussed capacitor selection for power factor improvement in other articles. Today we will discuss the PFI Panel Circuit Diagram and internal devices of the power factor improvement panel. You will get a clear concept of the PFI panel circuit diagram after reading this article.

PFI panel circuit diagram

For better understanding, we will look at some devices which we will get inside a power factor improvement panel.

1. Busbar 

2. HRC ( High rupturing capacity) fuse

3. Magnetic contactor 

4. Fixed capacitor

5. Power factor correction relay

6. Indicator light

It has to be noted that, we can control the power factor improvement panel in two ways:

1. Manually by push switch.

2. Automatically by power factor relay.

First, we will discuss the manual operation. We can see the connection diagram in the picture. There is a balloon-shaped device that is a fixed capacitor. This device is used for improving power factors. These devices are placed in different stages.

How Many Stages do We Need and How to Know the Number of Stages?

There are 6,12,24 stages. It depends on the capacity of your factory load. Generally, considering the power rating of the factory transformer the fixed capacitor will be placed in stages. 

1. 6 stage for 500 kVA.

2. 12 stage for 500-1000 kVA

3. 24 stage for 1000 kVA.

And the process is placing values upwards. For example, you need a total of 60 kVA reactive power and if you want to place them in 6 stages the sequence will be 6,8,9,10,12,15 kVA. And the capacitors have parallel connections for getting 380/400/440 volt from the LT panel.

PFI Panel Circuit Diagram

1. 380/400/440 volt supply enters busbar of PFI panel by LT panel’s MCCB.

2. HRC fuse works as the security between the busbar and LT panel.

3. A magnetic contactor helps each capacitor to get a 380/400/440 volt supply from the busbar.

4. Here capacitors have a direct online starter connection with a magnetic contactor. 

5. Capacitors are placed in 6 stages.

6. By activating the push switch, magnetic contactors normally open contact will close. And the capacitor will get power.

7. The activated capacitor will work for the correction of the power factor.

If you want to do it automatically, you have to use a power factor relay. It will supply power by magnetic contactor to fixed capacitor if the power factor decreases. This relay also has a connection with indicator light. Performing capacitor’s indicator light will get activated.

Power factor is a sensitive issue for the industry. The company has to pay a fine if the power factor is out of control. This fine is called a penalty charge. So, to get rid of paying fines and system loss PFI panel is a great weapon. Hope this article was helpful for understanding the PFI panel circuit diagram.

You can also read: Explanation of the power factor in an easy way.