ObjectiveObjective

Provide an analysis of the existing Provide an analysis of the existing Waltz-Mill system.Waltz-Mill system.

Determine the affect on the system Determine the affect on the system of adding an additional motor load.of adding an additional motor load.

Determine the necessary changes to Determine the necessary changes to safely add the new load and increase safely add the new load and increase the power factor on T6 and T7.the power factor on T6 and T7.

Existing System AnalysisExisting System AnalysisWith SKM Power Tools SoftwareWith SKM Power Tools Software

A Load Flow A Load Flow analysis was analysis was performed with the performed with the following data.following data.

BKR5BKR5 306kVA306kVA .8.8

T10T10 568kVA568kVA .8.8

BKR15BKR15 450.75k450.75kVAVA

.8.8

T11T11 220kVA220kVA .8.8

BKR10BKR10 225.81k225.81kVAVA

.8.8

BKR13BKR13 375.89K375.89KVAVA

.8.8

LocationLocation LoadLoad PFPF

T1T1 1300kVA1300kVA .8.8

T2T2 1275kVA1275kVA .8.8

BKR2BKR2 416.71k416.71kVaVa

.8.8

BKR3BKR3 No loadNo load

Existing System AnalysisExisting System AnalysisWith SKM Power Tools SoftwareWith SKM Power Tools Software

The following values will be found The following values will be found under the current conditionsunder the current conditions• Percent loading for each feeder circuitPercent loading for each feeder circuit• Percent loading for each transformerPercent loading for each transformer• Nominal voltage and percent voltage Nominal voltage and percent voltage

drop at each switchgeardrop at each switchgear• Optimal transformer tapsOptimal transformer taps

System Analysis with new loadSystem Analysis with new load

500hp motor load added to 500hp motor load added to secondary bus T7.secondary bus T7.

Determine the size of the cable and Determine the size of the cable and breaker.breaker.

Increase power factor on secondary Increase power factor on secondary bus of T6 and T7 to .97 by adding a bus of T6 and T7 to .97 by adding a capacitor bank.capacitor bank.

Results and RecommendationsResults and Recommendations

Load flow analysis Load flow analysis of existing system of existing system before tap before tap optimization.optimization.

Includes percent Includes percent loading for all loading for all transformers and transformers and feeders.feeders.

Results and RecommendationsResults and Recommendations

Tap settings were Tap settings were optimized to optimized to minimize loss in minimize loss in the system.the system.

Load Flow results with optimized tap settings

Results and RecommendationsResults and Recommendations

The full load ampacity The full load ampacity for the motor was for the motor was found with the found with the equation for FLequation for FLAA..

The breaker was sized The breaker was sized at 125% FLat 125% FLAA..

The size of the The size of the capacitor bank needed capacitor bank needed to improve the PF to improve the PF to .97 was found with to .97 was found with the equation for Qthe equation for QBB..

Added motor and capacitor bank to T7

Results and RecommendationsResults and Recommendations

Added capacitor bank to correct T6 power factor to 0.97

Results and RecommendationsResults and Recommendations

The motor drew up to The motor drew up to 683.92A683.92A

3-1/C, 500MCM, 3-1/C, 500MCM, nonmagnetic cable was nonmagnetic cable was chosen (ampacity of chosen (ampacity of 810A)810A)

A GE SK, Spectra motor A GE SK, Spectra motor circuit protector with trip circuit protector with trip settings between 600-settings between 600-1200A was selected.1200A was selected.

This trip current This trip current should be set to 800A. should be set to 800A.

Load flow analysis of system with motor and capacitor banks added