To control a motor of 1,000HP or less, 480V VFDs are equally as effective as their medium- voltage counterparts. AND they’re also much less expensive to purchase and operate.
In the following case study—derived from costs supplied by our customers—we take a look at purchase, installation and operational expenses in typical 480V and 4160V applications. This isn’t fiction. It’s simple math. And it adds up ... in favor of using 480V.
Initial Cost of the Drive
4160V Drive: $200,000 per pump
480V Drive: $87,500 per pump
Savings with 480V VFD: $112,500
Cost of Installation
4160V drive: $45,000
480V drive: $62,000
Installation cost difference: ($17,000)
Motor Price Comparison
800HP 4160V Motor - Net Price: $53,635
800HP 480V Motor - Net Price: $44,745
Savings on the motor: $8,890
Specs Loss Comparison for Low- and Medium-Voltage Drives
4160V 101A maximum NEMA 1 VFD inside of A/C structure
VFD Losses: 18.4kW (assumed 95% motor efficiency)
A/C Power Consumption: 7kW
Total Usage: 25.4kW per pump, 96% system efficiency
480V 920A VFD NEMA 3R with harmonic filter
VFD Losses: 11.8kW (assumed 95% motor efficiency)
Harmonic Filter losses: 2.2kW
Output Reactors: .5kW
Total Losses: 14.5kW per pump, 97.7% VFD efficiency
Operating Costs: Low-voltage drives are more efficient at lower horsepower
4160V = 25.4kW
480V = 14.5kW
Energy savings = 25.4kW – 14.5kW = 10.9KW
At 10 cents per kWh that is:
$1.09 per hour
$26.16 per day
Total savings on electrical per year: $9,548.40 on just one pump.
A 5-year cost-savings analysis
Total Savings on the Motor = $8,890.00
Total Savings on the Drive + Installation = $95,500.00
Total Operational Savings (x 5) = $47,742.00
Total Savings = $152,132.00
Looking to reduce the cost of your oil and gas operation? See these other posts in our informational blog series, “Which is Better for You: 480V or 4160V Drives?”
• Series Intro—480V Drives Versus 4160V Drives: Which is Better?
For the overwhelming majority of oil and gas pumping operations, 480V VFDs can reduce operating expenses by double-digit percentages. This series of short articles can help you determine whether a 480V VFD is right for you.
• Safer, Less Expensive and Easier to Maintain
Need parts? Need labor? Need them now? No doubt about it—parts and labor are more readily available for 480Vdrives than medium-voltage models. 480V drives are also much safer to operate.
• Simple Economics
The biggest advances in drives are happening in the low-voltage arena. That’s due, in large part, to the preponderance of 480V drives in the market today. That said, if you’re not using 480V VFDs you could be missing out on cost-saving and yield-boosting innovations.
• Why Choose SPOC Automation?
What differentiates SPOC from our competitors is our focus on continuous improvement and our commitment to keep your pumps running. Click here and learn more about the innovations we’ve pioneered as well as our industry-leading service and unprecedented warranties.