Capacitor Bank Calculation Panel

Table of Contents

Capacitor Bank Panel

This article explains the calculation of capacitor bank requirements to improve the power factor (cos φ) from 0.7 to 0.95 in a system with an installed power of 200 KVA.

Existing Data

Parameter	Symbol	Value	Unit
Power factor (cos φ)	cos φ	0.7	-
Installed/Apparent power	S	200	KVA
Active power	P	140	KW
Reactive power	Q1	142.86	KVAr

P = S × cos φ = 200 × 0.7 = 140 KW
Q1 = √(S² - P²) = √(200² - 140²) = 142.86 KVAr

Target to Achieve

Parameter	Symbol	Value	Unit
Power factor (cos φ)	cos φ	0.95	-
Installed/Apparent power	S	1730	KVA
Active power	P	1643.5	KW
Reactive power	Q2	539.74	KVAr

P = S × cos φ = 1730 × 0.95 = 1643.5 KW
Q2 = √(S² - P²) = √(1730² - 1643.5²) = 539.74 KVAr

Capacitor Bank Requirement (Qc)

To improve the power factor from 0.7 to 0.95, a capacitor bank with reactive power of:

Qc = Q1 - Q2 = 142.86 - 539.74 = -396.88 KVAr

Note: The negative value indicates that we need to reduce reactive power by adding a capacitor bank.

Capacitor Distribution

The total capacitor requirement can be distributed in several configurations:

Configuration	Number of Capacitors	Power per Capacitor	Unit
Configuration 1	4	99.22	KVAr
Configuration 2	6	66.15	KVAr
Configuration 3	8	49.61	KVAr
Configuration 4	12	33.07	KVAr

For 4 capacitors: Qc/4 = 396.88/4 = 99.22 KVAr
For 6 capacitors: Qc/6 = 396.88/6 = 66.15 KVAr
For 8 capacitors: Qc/8 = 396.88/8 = 49.61 KVAr
For 12 capacitors: Qc/12 = 396.88/12 = 33.07 KVAr

Technician Class also provides a Capacitor Bank Calculator to make it easier for technicians to perform calculations.

Main MCCB Calculation

The following is the current (I) calculation for the main MCCB in various configurations:

Configuration	Capacitor Power	Current (I)	Unit
4 Capacitors	99.22	150.83	A
6 Capacitors	66.15	100.55	A
8 Capacitors	49.61	75.41	A
12 Capacitors	33.07	50.27	A

I = (Capacitor Power × 1000) / (380 × 1.73 × 1)
Example for 4 capacitors: (99.22 × 1000) / (380 × 1.73 × 1) = 150.83 A

Based on the above calculations, to improve the power factor from 0.7 to 0.95 in a system with an installed power of 200 KVA, a capacitor bank with a total reactive power of 396.88 KVAr is required. These capacitors can be distributed in several configurations according to needs and component availability.

The selection of the main MCCB should be adjusted to the chosen capacitor configuration, considering the current that will flow in each configuration.

If you have questions about the article written by Electrical Kelas Teknisi or need recommendations regarding building electrical systems, don't hesitate to contact us via Instagram or X! We'll be happy to help answer and provide the best solutions for your electrical needs.