Why Repair Instead of Replace?
Many motors fail prematurely from problems that are easily repairable - bearing failure, winding insulation breakdown, rotor issues. These motors have decades of useful life remaining if properly repaired. Replacement should be the last option, not the first.
💵 Repair vs. Replace Cost Comparison
Motor Size | New Motor Cost | Typical Repair Cost | Your Savings |
---|---|---|---|
5 HP | $800-1,200 | $400-600 | $400-600 (50%) |
25 HP | $2,500-3,500 | $1,000-1,800 | $1,200-2,000 (50%) |
50 HP | $4,500-6,500 | $1,800-3,000 | $2,500-3,500 (50%) |
100 HP | $8,000-12,000 | $3,000-5,500 | $4,500-7,000 (50%) |
250 HP | $20,000-30,000 | $7,000-12,000 | $10,000-18,000 (50%) |
Plus: Repaired motors often last 15-20 years with proper maintenance. You're not just saving money today - you're getting decades more service.
Additional Advantages of Repair:
- Faster Than Ordering: Most repairs completed in 3-7 days vs. weeks for new motor delivery.
- Perfect Fit: Your repaired motor drops right back in. No mounting modifications needed.
- Environmentally Responsible: Reduces waste and preserves resources.
- Tax Benefits: Repairs are typically fully deductible in year incurred vs. depreciation schedule.
- Preserves Rare Motors: Obsolete or special motors that can't be replaced must be repaired.
Motor Types We Repair & Rewind
We service all motor types and brands - if it has windings, we can rewind it:
AC Induction Motors
Types:
- Single-phase (1/4 HP - 10 HP)
- Three-phase (1/2 HP - 500 HP)
- TEFC (Totally Enclosed Fan Cooled)
- ODP (Open Drip Proof)
- TENV (Totally Enclosed Non-Ventilated)
Common Repairs: Rewind, bearing replacement, rotor repair, shaft machining
Explosion-Proof Motors
Classes: Class I Div 1 & 2, Class II, Class III
Groups: C, D, E, F, G
Specialized rewind procedures maintain UL/CSA listings. Proper clearances, flameproof joints, and approved materials.
Severe Duty Motors
Applications:
- Mining & aggregate
- Sawmills
- Washdown environments
- High vibration
- Inverter duty
Built to withstand harsh conditions with heavier construction and better insulation systems.
DC Motors
Types:
- Shunt wound
- Series wound
- Compound wound
- Permanent magnet DC
- Brushless DC (BLDC)
Services: Armature rewind, field coil rewind, commutator service, brush replacement
Brake Motors
AC motors with integrated electromagnetic brakes for instant stopping.
Services: Motor rewind, brake adjustment, brake coil replacement, spring replacement, friction disc service
High Voltage Motors
Voltages: 2300V, 4000V, 4160V, 6900V, 13,200V
Specialized insulation systems (VPI, resin-rich), surge testing, and high-pot testing. Form-wound coils for larger motors.
Wound Rotor Motors
Slip-ring motors for variable speed or high starting torque applications.
Services: Stator rewind, rotor rewind, slip ring service, brush holder repair, carbon brush replacement
Gearmotor Units
Motors with integrated gearboxes.
Services: Motor repair/rewind, gearbox inspection, oil change, seal replacement, gear inspection, complete unit testing
Our Complete Repair Process
Every motor repair follows our proven 10-step process to ensure quality results:
Inspection & Diagnosis
Thorough examination to identify all problems, not just symptoms.
- Visual inspection for obvious damage
- Insulation resistance test (megger)
- Continuity testing of all windings
- Bearing condition assessment
- Shaft runout measurement
- Frame condition check
- Nameplate verification
- Photograph all damage
- Document findings on inspection report
Written Quote & Approval
Detailed quote with all recommended work clearly explained.
- Itemized pricing for each repair
- Explanation of problems found
- Repair vs. replace recommendation
- Estimated completion time
- Alternative options if applicable
- No work begins until you approve
Disassembly & Parts Removal
Careful disassembly to preserve reusable components.
- Remove all external components (junction box, conduit fittings, mounting hardware)
- Mark end bell positions for proper reassembly
- Remove bearings using proper pullers
- Extract rotor carefully to avoid damage
- Remove old windings if rewind needed
- Clean and inspect all parts
- Identify parts needing replacement
Stator Core Preparation
Prepare stator for new windings if rewind required.
- Burn-out or Chemical Strip: Remove old windings (chemical stripping preferred for better insulation preservation)
- Core Testing: Verify core integrity with core loss tester
- Slot Cleaning: Remove all old varnish and insulation residue
- Inspection: Check for damaged laminations, corrosion, loose core
- Repair: Address any core damage before rewinding
Precision Rewinding
Wind new coils to exact OEM specifications.
- Winding Data: Use original winding data or calculate from motor parameters
- Wire Selection: Correct gauge magnet wire, insulation class (Class F or H typical)
- Slot Insulation: Install appropriate slot liners
- Coil Winding: Wind coils using computer-controlled winding machine for consistency
- Coil Installation: Insert coils into stator slots
- Wedge Installation: Secure coils with proper wedges
- Lead Connections: Wye or delta configuration per nameplate
- Lead Support: Proper lacing and bracing
Varnish Treatment (VPI)
Vacuum Pressure Impregnation for superior insulation.
- Pre-heat: Remove moisture from windings
- Vacuum Stage: Remove air from between turns
- Varnish Flood: Flood winding with insulating varnish under vacuum
- Pressure Stage: Force varnish deep into winding
- Bake: Cure varnish at controlled temperature
- Result: Monolithic winding with excellent moisture resistance and mechanical strength
Rotor Service
Inspect and repair rotor assembly.
- Squirrel Cage Rotors: Check for broken bars, inspect end rings, test for core problems
- Wound Rotors: Rewind if needed, service slip rings, check connections
- Shaft Inspection: Check for wear, scoring, bending
- Shaft Repair: Machine or repair as needed, build up worn areas with metalizing
- Key/Keyway: Inspect and repair
- Dynamic Balance: Balance rotor to ISO standards (typically G2.5 or G6.3)
Frame & Component Reconditioning
Restore frame and associated parts.
- Bearing housing inspection and repair
- Bearing fit verification (proper press fit critical)
- Frame straightening if needed
- Mounting holes/threads repaired
- Sandblast and paint frame
- Fan cleaning or replacement
- Fan cover repair
- Junction box recondition
Assembly & Testing
Reassemble motor and verify performance.
- Bearing Installation: Install new bearings with proper heat/press methods
- Reassembly: Install rotor, align end bells, torque all fasteners per spec
-
Electrical Testing:
- Insulation resistance (megger): Verify >100 megohms typically
- Surge test: Identify turn-to-turn faults
- Hi-pot test: Verify insulation integrity at 2x voltage + 1000V
- Continuity: Check all phases balanced
- No-Load Run Test: Run motor without load, check current draw, noise, vibration, temperature
- Load Test: Apply load if possible, verify performance matches nameplate
Final Inspection & Documentation
Quality check and provide complete records.
- Final visual inspection
- Verify all tests passed
- Create new nameplate if original damaged
- Rotation direction verification and marking
- Touch-up paint as needed
- Package for shipment/pickup
-
Documentation Provided:
- Test report with all measurements
- Before/after photos
- Parts replaced list
- Warranty certificate
- Maintenance recommendations
Common Motor Failure Causes
Understanding why motors fail helps prevent repeat failures:
Bearing Failure
Causes: Over-greasing, under-greasing, misalignment, contamination, wrong bearing type, excessive radial/axial load
Prevention: Proper lubrication schedule, laser alignment, proper coupling selection, vibration monitoring
Winding Insulation Failure
Causes: Overheating (overload, poor ventilation, phase loss), moisture contamination, voltage spikes, age degradation
Prevention: Proper ventilation, surge protection, moisture seals, load monitoring, VFD filters
Rotor Problems
Causes: Broken rotor bars, damaged end rings, excessive starting cycles, mechanical impact, poor casting quality
Prevention: Reduce start frequency, soft starters, proper motor sizing, avoid mechanical shock
Shaft & Mechanical
Causes: Shaft bending, keyway damage, shaft wear, loose rotor, bearing failure cascade
Prevention: Proper alignment, avoid side loads, correct coupling type, proper mounting
Contamination
Causes: Dust ingress, moisture, chemical exposure, oil/grease on windings
Prevention: Proper enclosure type (TEFC vs ODP), environmental seals, regular cleaning
Other Causes
Electrical supply problems (voltage imbalance, harmonics), improper installation, manufacturing defects, operating outside design parameters
Repair Turnaround Times
Service Type | Standard Turnaround | Rush Service |
---|---|---|
Rewind Only (fractional - 25 HP) | 3-5 days | 24-48 hours |
Rewind Only (25-100 HP) | 5-7 days | 2-3 days |
Rewind Only (100-500 HP) | 7-10 days | 3-5 days |
Complete Rebuild (rewind + bearings + shaft) | 5-10 days | 3-5 days |
Bearing Replacement Only | 1-2 days | Same day |
Testing & Evaluation Only | 1-2 days | Same day |
Explosion-Proof Rewind | 7-14 days | 4-7 days |
DC Motor Rewind (armature + field) | 7-10 days | 3-5 days |
Rush Service Premium: 50-100% surcharge depending on urgency. Available 24/7 for critical equipment.
Motor Repair Pricing
Pricing varies based on motor size, type, and extent of damage. Here are typical ranges:
Standard AC Motor Rewind Pricing:
Motor Size | Rewind Only | Complete Rebuild |
---|---|---|
1-5 HP | $300-600 | $500-900 |
5-10 HP | $500-900 | $800-1,400 |
10-25 HP | $800-1,500 | $1,200-2,200 |
25-50 HP | $1,200-2,500 | $1,800-3,500 |
50-100 HP | $2,000-4,000 | $3,000-6,000 |
100-200 HP | $3,500-7,000 | $5,000-10,000 |
200-500 HP | $6,000-15,000 | $9,000-20,000 |
Specialty Motor Pricing Multipliers:
- Explosion-Proof: Add 25-40% to standard pricing
- High Voltage (>600V): Add 30-50% to standard pricing
- DC Motors: Add 20-35% to standard pricing
- Wound Rotor: Add 40-60% to standard pricing
- Severe Duty: Add 15-25% to standard pricing
Additional Services:
Service | Price Range |
---|---|
Bearing Replacement (per bearing) | $75-300 + bearing cost |
Shaft Machining/Repair | $200-800 |
Dynamic Balancing | $150-500 |
Load Testing | $200-600 |
Vibration Analysis | $150-400 |
Frame Repair/Straightening | $300-1,500 |
Sandblast & Paint | $200-800 |
Our Warranty
What's Covered (1 Year)
- Rewinding workmanship
- Insulation system
- All installed parts
- Bearing installation
- Shaft repair work
- Assembly procedures
- Testing accuracy
- Mechanical repairs
What's NOT Covered
- Misuse or abuse
- Operating outside nameplate ratings
- Improper installation after pickup
- Lightning or power surge damage
- Contamination after delivery
- Accidents or external damage
- Normal bearing wear (unless premature)