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.

5 Warning Signs Your Electric Motor Needs Immediate Attention

Jeremy Hixson
Apr 13
3 min read

Unplanned equipment downtime costs industrial facilities an estimated $50 billion per year across the United States. For California manufacturers, agricultural operations, and water treatment facilities, a single electric motor failure can halt production for hours or even days. The good news is that most motor failures don't happen without warning. Here are five signs that your electric motor needs immediate professional attention.

1. Unusual Vibration or Noise

A healthy electric motor runs smoothly with minimal vibration. If you notice increased vibration, grinding sounds, rattling, or humming that wasn't there before, something is wrong. Common causes include worn bearings (the most frequent cause of motor failure), misalignment between the motor and driven equipment, imbalanced rotating components, or loose mounting bolts. Vibration analysis is one of the most effective predictive maintenance tools available. At Ace Electric Motor & Pump Co., we use precision vibration analysis equipment to diagnose problems before they cause catastrophic failure.

2. Overheating

Electric motors generate heat during normal operation, but excessive heat is a red flag. If the motor housing is too hot to touch (above 170°F for most motors), if you smell burning insulation, or if thermal protection devices are tripping frequently, the motor needs attention. Overheating can be caused by overloading, poor ventilation, voltage imbalance, deteriorating winding insulation, or high ambient temperatures. Every 18°F increase above a motor's rated temperature cuts insulation life in half. Catching overheating early can mean the difference between a simple repair and a complete rewind.

3. Decreased Performance or Efficiency

If your motor-driven equipment isn't performing like it used to — pumps aren't moving as much water, fans aren't pushing as much air, conveyors are running slower — the motor may be losing efficiency. This gradual decline often goes unnoticed because it happens slowly over months or years. A motor efficiency test can quantify exactly how much performance you've lost and help determine whether repair or replacement is the best path forward.

4. Excessive Energy Consumption

If your electricity bills are climbing without a clear explanation, deteriorating electric motors could be the culprit. Motors account for approximately 70% of all industrial electricity consumption. A motor operating at reduced efficiency draws more current to produce the same output, directly increasing your energy costs. Compare current amperage readings to the motor's nameplate values — if the motor is consistently drawing more than rated amps, it's working harder than it should.

5. Visible Damage or Deterioration

Physical signs of motor distress include a burnt smell near the motor indicating insulation breakdown, discoloration or darkening of the motor housing, oil or grease leaking from bearing seals, shaft wear visible at the coupling point, rust or corrosion on the frame, and cracked or broken mounting feet. Any of these signs warrant immediate inspection by a qualified motor repair technician.

Prevention Is Always Cheaper Than Emergency Repair

The most cost-effective approach to motor maintenance is catching problems early through a preventive maintenance program. Regular inspections, vibration analysis, thermographic imaging, and insulation resistance testing can identify developing problems weeks or months before they cause failure. Ace Electric Motor & Pump Co. offers comprehensive preventive maintenance programs for facilities throughout California's Central Valley. Our EASA-accredited technicians have been keeping Central Valley businesses running since 1952. Contact us at (209) 464-6428 to schedule an inspection, or reach out for 24/7 emergency service.