Alternator Repair Kenya
PowerPro Kenya is the leading provider of alternator repair across the country. We support critical infrastructure with engineering-led solutions and rapid response times.
Precision Electrical Winding and Repair
Alternator Repair & Rewinding Process
Phase 1: Electrical Testing & Assessment
We perform Megger testing, winding resistance checks, and diode bridge testing to determine the extent of the electrical fault.
Phase 2: Dismantling & Inspection
The alternator is carefully separated from the engine. We inspect the bearings, rotor shaft, and stator core for mechanical damage.
Phase 3: Rewinding & Varnishing
If windings are burnt, we strip the old copper, rewind using high-grade enameled wire, and apply Class H insulating varnish.
Phase 4: Reassembly & Testing
We install new bearings, reassemble the unit, and perform a full load test to verify voltage stability and insulation resistance.
Common Alternator Faults We Resolve
We diagnose and repair complex electrical faults within the alternator:
Loss of Residual Magnetism
The alternator produces 0-10V instead of 415V. We "flash the field" using a DC battery to restore the magnetic field in the exciter.
Unbalanced Phase Voltages
L1, L2, and L3 show significantly different voltages. We check for shorted turns in the main stator or severe load imbalances in the facility.
Alternator Overheating
Caused by blocked cooling vents, overloading, or low power factor (reactive power) loads. We clean the windings and analyze the facility load profile.
High Pitch Whining or Grinding
Indicates mechanical failure, usually the main alternator bearing. We use vibration analysis to confirm bearing wear before it collapses.
Generators & Brands We Service
Our technical expertise spans across all major industrial and commercial diesel power systems. We provide specialized generator brand repair for:
What Our Alternator Service Includes
Insulation Resistance (Megger) Testing
Applying high voltage to the windings to measure insulation breakdown, ensuring the alternator is safe to operate and won't short to ground.
AVR & Excitation Repair
Replacing faulty Automatic Voltage Regulators, testing the exciter stator/rotor, and replacing blown rotating diode assemblies.
Bearing Replacement
Extracting and replacing worn alternator bearings to prevent rotor-to-stator rubbing, which causes catastrophic failure.
Complete Rewinding
Stripping burnt copper, cleaning the core, and rewinding the stator or rotor using high-grade copper wire and Class H varnishing.
Technical Insight: The Rotating Diode Assembly
A common cause of "no voltage" is a failed rotating diode on the exciter rotor. Diodes usually fail due to voltage spikes from sudden load rejection or out-of-phase synchronization. We test these diodes using a multimeter in diode mode; if one is shorted or open, we replace the entire bridge assembly and install a new surge suppressor (varistor) to protect the new diodes.
National Service Coverage
PowerPro Kenya maintains a network of mobile engineering teams stationed in major hubs across the country. This allows us to provide rapid response times for critical infrastructure in any county.
Major Hubs We Serve
- Nairobi
- Mombasa
- Kisumu
- Nakuru
- Eldoret
- Thika
- Homa Bay Town
- Kakamega
National Standards
- National grid instability
- Critical infrastructure uptime
- Industrial power demand
Frequently Asked Questions
Is it better to rewind an alternator or buy a new one?
For smaller alternators (under 50kVA), buying a new replacement is often more cost-effective. For larger industrial alternators (250kVA+), rewinding is significantly cheaper and, when done correctly with Class H insulation, provides a lifespan equal to a new unit.
What is a Megger test?
A Megger (Megohmmeter) test applies a high DC voltage (usually 500V or 1000V) to the windings to measure the resistance of the insulation. A reading below 1 Megohm indicates moisture or insulation breakdown, meaning the alternator is unsafe to run.
Why did my AVR blow up?
AVRs typically fail due to severe overloading, short circuits on the output, or operating the generator at a very low engine speed (under-frequency) for extended periods, which causes the AVR to over-excite and burn out.
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Industrial-grade support for the Kenya.