Three-Phase Power Imbalance; Changing Motor Rotation - GE OSMONICS TONKAFLO SS1000 SERIES Installation, Operation And Maintenance Manual

D.
3.6.3

Three-Phase Power Imbalance

Current imbalance should not exceed 5% of the average three-phase current.
The current imbalance can be calculated as follows:
STEPS
1. Measure the current through each of the three legs.
2. Average the three current measurements together.
3. Determine the difference between the current in each leg and the
average of all three legs.
4. Take the difference with the largest value, and divide it by the average
current. Multiply by 100 to obtain the current imbalance percentage.
5. If the current imbalance is greater than 5%, "roll" the leads and retest
(Figure 3.4, Rolling the Leads to Balance Current Rotation). If "rolling"
the leads does not correct the problem, the source of imbalance must
be located and corrected. For more information on current imbal-
ance, refer to the motor operation manual.
Compare the results observed. The wire connection that yield-
ed the highest pressure and flow rate is the proper connection.
Interchange the
(Figure 3.3, Changing Motor Rotation).
Figure 3.3
Changing Motor
Rotation
10
two leads only if necessary