Busway - Specifications Tab

Figure 1: Specifications Tab

Option Descriptions
Option Description

Unit

Select either U.S. or Metric.

Mfr

Provides a list of manufacturers available in the device library. If the desired manufacturer is not listed in the device library, you can add it to the library.

Type

Equipment types available from the selected manufacturer. If the desired type is not listed, you can add it to the library.

Length

The length of the busway in feet or meters.

Ampacity

Busway rating in amperes. After you choose a manufacturer and type, the available ampacities are displayed here. If the desired manufacturer is missing from the list, you can select Generic in the Mfr field and (std) in the Type field to select from generic options.

Material

The busway material (copper or aluminum).

Impedances
 

Impedances are described in ohms/100 feet or ohms/100 meters. Zero sequence impedances are found from the positive sequence impedance using a Z0/Z1 multiplier from Reference1.

Reference:
1 Let's Be More Specific About Equipment Grounding, R.H. Kaufmann, General Electric Co., GER 1974.

R1

Positive sequence resistance.

Note: For single phase, this is the one-way resistance. Analysis doubles the value to account for the return path.

X1

Positive sequence reactance.

Note: For single phase, this is the one-way reactance. Analysis doubles the value to account for the return path.

R0

Zero sequence resistance. If you enter this value as zero (0.0), the positive sequence impedance is used.

X0

Zero sequence reactance. If you enter this value as zero (0.0), the positive sequence impedance is used.

Auto-calculate

When selected, this checkbox fills in computed values for the impedances R1, X1, R0, and X0 fields. The calculations are based on the specific manufacturer’s data for the type of busway chosen with the Mfr, Type, Ampacity, and Material fields.

If the checkbox is cleared, you can enter your own calculated values.

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