What is a Variable Frequency Drive (VFD)?

A Variable Frequency Drive (VFD) is an electronic device that controls the speed of an AC electric motor by varying the frequency of the electrical power supplied to it. Instead of running at full speed 100% of the time, a VFD slows the motor to match actual demand, similar to cruise control for your motor.

How much money can a VFD save on energy costs?

VFDs can reduce electric motor energy consumption by 20% to 50% depending on the application. For a 100 HP motor running 8,000 hours per year in California, that translates to $15,000 to $25,000 in annual electricity savings.

What is the typical payback period for VFD installation?

Most VFD installations pay for themselves in 12 to 15 months through energy savings alone. Over the 15-year life of the equipment, net savings can exceed $200,000 for a single motor. California utility rebates from PG&E can cover 25-50% of the installation cost, making the payback even faster.

What applications benefit most from VFD installation?

VFDs deliver the greatest savings on applications where the load varies, including irrigation pumps, HVAC systems, wastewater treatment pumps and blowers, cooling tower fans, and conveyor systems. Any pump, fan, or compressor that runs at less than full capacity for significant periods is a strong candidate.

Are there California rebates available for VFD installation?

Yes. PG&E and other California utilities offer energy efficiency rebates for VFD installations through their customized incentive programs. These rebates can cover 25% to 50% of the installation cost. An experienced VFD installer like Ace Electric Motor & Pump Co. can help navigate the rebate application process.

What are common VFD installation mistakes to avoid?

The five most common mistakes are improper sizing based on horsepower instead of full-load amperage, ignoring harmonic distortion that affects other equipment, inadequate cooling and ventilation for the drive, exceeding cable length limits between the VFD and motor which causes voltage spikes, and skipping a motor assessment to determine if the existing motor needs insulation upgrades.

How much does electric motor repair cost?

Electric motor repair costs vary based on motor size, type of failure, and repair needed. Small motor repairs typically start at $200-$500, while large industrial motor rewinds can range from $2,000-$15,000+. Ace Electric Motor and Pump Co. provides free estimates — call (209) 464-0781.

Should I rewind or replace my electric motor?

The decision depends on motor size, age, efficiency class, and repair cost vs. replacement cost. Generally, motors over 50 HP are often more cost-effective to rewind. Motors under 10 HP may be cheaper to replace. An EASA-accredited shop like Ace Electric can evaluate your motor and recommend the most cost-effective option.

What causes electric motor failure?

The six most common causes of electric motor failure are: bearing failure (over 50% of failures), winding insulation breakdown from overheating, voltage imbalance, contamination from moisture or dirt, overloading beyond rated capacity, and misalignment. Preventive maintenance programs can catch most issues early.

How long does electric motor repair take?

Standard electric motor repairs typically take 3-5 business days. Emergency rush service is available for critical production motors, often with 24-48 hour turnaround. Large motor rewinds may take 1-2 weeks. Ace Electric Motor offers emergency service — call (209) 464-0781.

What is EASA accreditation and why does it matter?

EASA (Electrical Apparatus Service Association) accreditation means a motor repair shop follows strict quality standards for repair and testing. EASA-accredited shops ensure your motor is returned to original manufacturer specifications or better, protecting your investment and ensuring reliability.

Do you offer on-site electric motor repair?

Yes, Ace Electric Motor and Pump Co. provides on-site maintenance and repair services throughout Stockton, CA and the Central Valley. Our mobile technicians perform vibration analysis, laser alignment, troubleshooting, and many repairs at your facility to minimize downtime.

What types of pumps do you repair?

Ace Electric repairs all types of industrial and commercial pumps including centrifugal, submersible, vertical turbine, positive displacement, booster, and sewage pumps. We service all major brands and provide both in-shop and on-site pump repair in Stockton, CA.

What is a VFD and do you install them?

A VFD (Variable Frequency Drive) controls motor speed by varying electrical frequency. VFDs save energy, reduce mechanical stress, and provide precise speed control. Ace Electric installs, programs, and repairs VFDs from ABB, Siemens, Allen-Bradley, Yaskawa, and other major manufacturers.

How much does industrial gearbox repair cost?

Industrial gearbox repair costs typically range from $800 to $5,000 for small to mid-size gear reducers, and $5,000 to $25,000 or more for large industrial gearboxes requiring extensive gear replacement or custom machining. The final cost depends on gearbox size, type (worm, planetary, helical, or bevel), extent of damage, and whether replacement gears need to be manufactured. At Ace Electric Motor & Pump Co., we provide a free inspection and written estimate before any work begins.

How long does gearbox repair take?

Standard gearbox repairs are typically completed in 5 to 10 business days, depending on the scope of work and parts availability. For critical production equipment, we offer emergency and expedited service with turnaround as fast as 48 to 72 hours. On-site field repairs for diagnosis and minor repairs can often be completed same-day.

Should I repair or replace my gearbox?

Repairing is usually the better option when the gearbox housing is structurally sound, replacement parts are available or can be manufactured, and the repair cost is less than 50-60% of a new unit. Replacement makes more sense when the housing is cracked beyond repair, the design is obsolete, or repeated failures indicate a fundamental mismatch for your application.

What are the most common causes of gearbox failure?

The six most common causes of industrial gearbox failure are: inadequate or contaminated lubrication (the leading cause), bearing fatigue from misalignment or overloading, gear tooth wear or pitting from sustained heavy loads, seal failures that allow contaminant ingress, thermal overload from insufficient cooling, and improper installation or shaft alignment.

Do you offer on-site gearbox repair?

Yes. Ace Electric Motor & Pump Co. provides 24/7 on-site field service for gearbox diagnosis, minor repairs, alignment, and oil changes across the entire Central Valley, including Stockton, Sacramento, Modesto, Tracy, and surrounding communities.

What brands of gearboxes do you repair?

We repair gearboxes from all major manufacturers including SEW-Eurodrive, Nord, Falk (Rexnord), Dodge, Sumitomo, Winsmith, Boston Gear, Bonfiglioli, Brevini, Flender (Siemens), Hansen, and David Brown Santasalo. We also repair discontinued and legacy gearboxes using our precision machine shop to manufacture components to OEM specifications.

What does EASA accreditation mean for gearbox repair?

EASA (Electrical Apparatus Service Association) accreditation means that Ace Electric Motor & Pump Co. follows documented quality standards for repair processes, testing procedures, and workmanship. An accredited shop undergoes regular audits and maintains calibrated equipment, trained technicians, and traceable quality records.

Can you manufacture replacement gears?

Yes. Our on-site precision machine shop can manufacture spur gears, helical gears, worm wheels, bevel gears, splines, and keyways. This is especially valuable for legacy gearboxes where OEM parts are discontinued. We reverse-engineer worn gears, manufacture replacements from high-quality alloy steels, and heat-treat them to match or exceed original specifications.

When Should You Rewind vs. Replace Your Electric Motor?

josh7486
Mar 19
3 min read

When a critical electric motor fails at your facility, you face an urgent decision: should you rewind (rebuild) the motor or replace it entirely? The answer depends on several factors including motor age, condition, efficiency requirements, and cost. As an EASA-accredited repair facility serving the Central Valley since 1952, Ace Electric Motor & Pump has helped thousands of operations managers make this exact call. Here is what you need to know.

What Is Electric Motor Rewinding?

Electric motor rewinding is the process of removing the old, damaged copper wire windings from a motor's stator or rotor and replacing them with new windings. This restores the motor's electromagnetic properties and allows it to run like new. A quality rewind performed by an EASA-accredited shop preserves the motor's original efficiency and performance specifications.

At Ace Electric, our rewinding process includes complete disassembly, burnout oven processing, core testing to verify the lamination integrity, precision winding with new copper wire, VPI (vacuum pressure impregnation) varnishing, and comprehensive testing before the motor leaves our shop.

When Rewinding Makes Sense

Rewinding is typically the best choice when the motor's core (iron laminations) is still in good condition. A core loss test will confirm this. If the core passes, a rewind can restore the motor to original specifications at 40-60% of the cost of a new motor. This is especially true for larger motors (50 HP and above), where replacement costs can be significant.

Rewinding also makes sense when the motor is a specialty design, such as explosion-proof motors used in oil and gas or chemical processing environments, or custom-built motors with unusual specifications. Replacement motors with matching specs may have long lead times of 12-20 weeks or more, while a quality rewind can often be completed in days.

When Replacement Is the Better Option

Replacement makes more sense for smaller motors, generally under 15-25 HP, where the cost difference between rewinding and buying new is minimal. Modern premium-efficiency motors (NEMA Premium / IE3) also deliver significant energy savings that can offset the higher purchase price over time. If your motor has been rewound multiple times already, or if the core test reveals lamination damage, a new motor is the smarter investment.

Motors that are 30+ years old and have been operating in harsh environments (extreme heat, moisture, corrosive chemicals) may also be better candidates for replacement due to cumulative wear on bearings, shafts, and housings that goes beyond what a rewind addresses.

The Cost Comparison

As a general rule of thumb: if the rewind cost is less than 50-65% of a new motor purchase price, rewinding is usually the economical choice, provided the core is healthy. But cost alone should not drive the decision. Consider the total cost of ownership including energy efficiency, expected remaining lifespan, and the cost of downtime while waiting for a replacement.

How Ace Electric Helps You Decide

At Ace Electric Motor & Pump, we never push you toward one option over the other. When you bring in a failed motor (or we pick it up with our 24/7 field service), we start with a thorough evaluation: visual inspection, insulation resistance testing, core loss testing, and a detailed assessment of the mechanical components. We then provide you with an honest recommendation and a clear quote for both options so you can make an informed decision.

As an EASA-accredited facility, we follow strict quality standards that ensure a rewound motor maintains its original efficiency rating. Only the top 3% of repair shops in the country carry this accreditation.

Need Help With a Motor Decision Right Now?

Whether you are dealing with a motor failure on your production line, at a wastewater treatment plant, in a food processing facility, or anywhere across the Central Valley, Ace Electric Motor & Pump is here to help. We have been keeping facilities running in Stockton, Sacramento, Modesto, Tracy, and throughout Northern California since 1952.

Call us at 209-464-6428 for a free motor evaluation. We offer 24/7 emergency service and can often have your motor evaluated the same day.