Voltage Rating

Number of

kVAR Rating

BIL kV

(rms)

Phases

216

5, 7.5, 131/3, 20, and 25

1 or 3

30

240

2.5, 5, 7.5,10, 25, 20, 25, and 50

1 or 3

30

480

5, 10, 15, 20 25, 35, 50, 60, and 100

1 or 3

30

600

5, 10, 15, 20 25, 35, 50, 60, and 100

1 or 3

30

2,400

50, 100, 150, and 200

1

75

2,770

50, 100, 150, and 200

1

75

4,160

50, 100, 150, and 200

1

75

7,200

50, 100, 150, 200, 300, and 400

1

95

12,470

50, 100, 150, 200, 300, and 400

1

95

13,800

50, 100, 150, 200, 300, and 400

1

95 and 125

Refer to IEEE 18 for ratings at other voltages.

C-3.2

The calculated capacitor size will rarely exactly match one of the available

sizes. The decision of whether to select the next larger or the next smaller size

depends on the circuit configuration and the desired power factor. Paragraph C -4

provides specific design criteria regarding capacitor size.

C-3.3

IEEE 18 establishes the required design tolerances for capacitors.

C-4

C-4.1

Consider requiring power factor correction as part of the facility design.

Power factor correction has to be justifiable based upon operational performance

improvements or cost-savings, including any potential effects caused by interaction with

other devices.

C-4.2

If used, apply capacitors to obtain a power factor range of 0.85 to 0.95. A

power factor of 0.85 will satisfy most operational requirements, but the actual minimum

value should also be based on any revenue metering penalties established by the local

commercial utility for low power factors. Little, if any, economic ad vantage will usually

be realized if attempting to correct above a power factor of 0.95. Ensure that power

factor correction will not cause a leading power factor under no -load conditions.

C-4.3

Power factor correction requires particular attention if nonlinear loads are a

significant portion of the facility load; this includes electronic equipment, ASDs, UPS

systems, and other significant sources of harmonic distortion. Capacitors can resonate

with nonlinear loads and cause additional distortion of the e lectrical system voltage and

current. In this case, the capacitor(s) might not improve the power factor at all. Also,

resonant conditions can cause capacitor failure. If facilities contain a significant

proportion of nonlinear loads, evaluate the application of a synchronous condenser

instead. Synchronous condensers are often applied at the service entrance, which

might not solve all power factor problems throughout the facility.

C-5

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