The efficiency of power generation, transmission, or conversion is improved when operated at near unity power factor. The least expensive way to achieve the same is by installing Capacitors. Capacitors must be able to withstand high voltage transients and power line variations without breakdown.
- Rated Voltage(AC): 230V,400V, 450V, 525V
- Rated Capacity: 1~30kvar
- Capacity deviation (μF): 0~+10% of the rated capacity
- Connection Type: Three-phase
- Rated Frequency: 50Hz
- Ambient Temperature: -25℃~+50℃
- AC withstands voltage:
Between shell and phase: 3kV/10s
- Allowable over-voltage (Un): 1.10 of rated voltage (not greater than 8h in 24h)
- Allowable over-current (In): 1.43 of rated current
- Voltage to the ground (Ue): 3000V AC 50Hz
- Altitude: ≤2000m
- Relative humidity:
≤50% at 40℃
≤90% at 20℃
- Appearance: Cylindrical
- Inside Dipping Material: Polypropylene metalized film
- Self-discharge characteristic: The residual voltage reduces to 50V or below from √2Un after 3 minutes in case of power failure
- Standard: IEC60831
Differentiations between these two series are concluded in the following:
1) Enclosure material
3) Connection method
HBSM: Single-phase, three-phase, three-phase four-wire
4) Rated voltage
HBSM: 230V, 250V, 280V, 400V, 415V, 440V, 450V, 480V, 525V, 660V, 690V
HDCAP3: 400V, 450V, 525V
HBSM: Box type
HDCAP3: Cylinder type
Explosion-proof design works as below:
(1) Various breakdowns happened;
(2) Polypropylene metallized film is decomposed to produce gas under high temperature;
(3) A great amount of gas is unable to be released to increase the pressure inside the capacitor;
(4) The top cover is deformed as the inner pressure is increasing.
The selection should be done after derating the Circuit Breaker taking into consideration voltage variation and capacitors tolerances that could increase nominal current up to 1.5In.
The Derating factor of 1.5In
Where In = Q/ ( Square root of 3 ) Un
Q = Capacitor Power
Un = Nominal Voltage
Choose the Micrologic with delay time selection, so that the Circuit Breaker does not trip due to initial high inrush current.
Also to be taken into account are the parameters like supply frequency, operating voltage & harmonics level of the power system for such application.
Refer the attached sheet for further details for selection of Circuit Breaker for Capacitor duty application.
Note: Use the phase barrier between the phases in Circuit Breaker to prevent flashover due to heavy inrush current.
Main conditions are as follows:
(1) Load connection: rectifier, VSD, soft starter
(2) Grid environment: refining, chemical industry, cement, electroplating
(3) Main order of harmonics: 5th, 7th, 11th
(4) Specified capacitor switching contactor is replaced by commercial AC contactor: easy to shorten lifecycle of capacitors due to inrush current suppression ability (capacity reduction risk)