208V groups or one three-phase 208V

three single-phase 120V loads and the

group may be served.

To balance this

three single-phase 208V loads should

system, the three single-phase load

be balanced.

groups should be of equal size. A 3

a. Example.

Returning

to

the

4W 120/208V system contains three hot

example of lesson 1, balance

the

wires and a neutral, meaning that

loadings

on

the

The

three single-phase 120V loads, three

following loads were given:

single-phase 208V loads, and a three-

phase 208V load may be served.

The

b. Solution.

The loads should be distributed so that each phase carries an

approximately equal load and so that removal of any one load will still leave

approximately equal loads on each phase.

One possible method of distribution is

shown in figure 5. This results in a distribution as follows:

The ideal situation would be for each phase to carry an exactly equal load but this

is almost never achieved in practice.

Here the loadings on the generator are

balanced to 4.2%

.

This is within the required 10 percent.

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