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.

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.

How Much Does Electric Motor Repair Cost in 2026?

josh7486
Mar 19
3 min read

When an electric motor fails at your facility, one of the first questions is: how much will it cost to repair? The answer depends on several factors including motor size, the type of failure, and the urgency of your timeline. This guide breaks down what drives electric motor repair costs so you can budget effectively and make informed decisions about repair versus replacement.

Factors That Affect Motor Repair Cost

Motor Size (Horsepower)

Motor size is the biggest single factor in repair cost. A fractional horsepower motor used in an HVAC blower is a fundamentally different job than a 500 HP motor driving a cooling water pump. Larger motors require more copper wire for rewinding, more labor hours for disassembly and reassembly, heavier equipment to handle, and more comprehensive testing. As a general guideline, small motors (under 10 HP) may cost a few hundred dollars to rewind, while large motors (200+ HP) can cost several thousand.

Type of Failure

A simple bearing replacement is on the lower end of the cost spectrum. A full rewind (replacing all the copper windings) costs more but restores the motor to like-new electrical condition. Mechanical repairs like shaft machining, housing reboring, or end bell repair add to the total. If the motor has multiple issues, such as bad bearings, damaged windings, and a worn shaft, the combined repair cost increases but may still be significantly less than replacement.

Motor Type and Complexity

Standard NEMA frame three-phase induction motors are the most straightforward and economical to repair. Specialty motors cost more due to their complexity: explosion-proof (XP) motors require certified assembly procedures, DC motors have additional components like commutators and brushes, servo motors require precision encoder alignment, and vertical motors may need special fixtures for handling. Older or imported motors with non-standard frames can also add cost if custom parts are needed.

Turnaround Time

Emergency and rush repairs cost more because they require overtime labor, expedited parts procurement, and rearranging the shop schedule. If your motor failure is not stopping production, a standard turnaround allows the shop to schedule your repair efficiently and keep costs down. At Ace Electric, we offer standard, expedited, and emergency turnaround options so you can balance cost against the urgency of getting your equipment back online.

The Repair vs. Replace Decision

A common rule of thumb in the industry is that if the repair cost is less than 50-65% of the price of a new motor, repair is typically the better economic choice, assuming the motor's core (lamination stack) is in good condition. For larger motors (50 HP and above), this math almost always favors repair. For smaller motors under 15-25 HP, the cost difference between a rewind and a new premium-efficiency motor narrows, and replacement may make more sense, especially when factoring in energy savings from a newer motor.

What Is Included in a Quality Motor Repair?

At an EASA-accredited shop like Ace Electric, a quality motor repair includes incoming testing and documentation, complete disassembly and cleaning, core loss testing to verify lamination integrity, precision rewinding with new copper wire, VPI (vacuum pressure impregnation) varnishing for moisture and contamination resistance, new bearings, dynamic balancing, and comprehensive final testing including hipot, surge, and vibration. You should receive a test report with your repaired motor.

Why EASA Accreditation Matters for Cost

Choosing an EASA-accredited repair shop may not be the cheapest option upfront, but it protects your investment. EASA standards ensure the motor maintains its original efficiency after repair, which means lower energy costs over the motor's remaining life. A poorly executed rewind at a non-accredited shop can reduce motor efficiency by 1-3%, which on a large motor running 24/7 adds up to thousands of dollars in wasted electricity per year. Only about 3% of motor repair shops carry EASA accreditation.

Get a Free Motor Evaluation from Ace Electric

The best way to know your exact repair cost is to have the motor evaluated by a qualified shop. At Ace Electric Motor & Pump in Stockton, CA, we provide free motor evaluations and detailed quotes that break down exactly what your motor needs and what it will cost. No surprises, no hidden fees. We also provide a quote for replacement so you can compare options side by side.

Serving manufacturing plants, wastewater facilities, food processors, HVAC contractors, and oil and gas operations across Stockton, Sacramento, Modesto, Tracy, and the entire Central Valley since 1952.

Call 209-464-6428 for a free evaluation and quote. 24/7 emergency service available.