Industrial Motor Feeder: 500HP Chiller Installation
Engineering a 500HP chiller motor feeder with voltage drop optimization for a manufacturing facility.
1.8% running voltage drop achieved
Eliminated voltage sag during motor starting
Reduced energy losses by 3% annually
$12,000 annual energy savings
Challenge
500HP motor requiring 600ft feeder run with strict voltage drop limits for motor starting
Solution
Parallel 500 kcmil conductors with VFD to manage starting current and voltage drop
Project Overview
A major manufacturing facility in Houston, Texas required installation of a new 500HP centrifugal chiller to expand cooling capacity. The chiller's motor, operating at 480V three-phase, would be located approximately 600 feet from the main electrical distribution switchgear.
Large industrial motors present unique electrical challenges because they operate in two distinct modes: starting and running. During starting, the motor can draw 6 to 8 times its full load current for 10 to 15 seconds.
The Solution: VFD with Parallel Conductors
VFD Benefits
- • Soft Starting: Limits starting current to 100-150% of FLC
- • Speed Control: Allows chiller capacity modulation
- • Power Factor Correction: Unity power factor reduces current draw
Final Design: 3 Sets of 500 kcmil per Phase
Effective Resistance: 0.0258 / 3 = 0.0086 Ω/kft
Running Vd% = 1.1% - Excellent!
Economic Analysis
Start Calculating
Ready to apply these concepts to your project? Use our professional voltage drop calculator.
Open Calculator