Generator Rewinding · Gauteng
Generator Rewinding.
Restored to Factory Specification.
When generator windings fail due to insulation breakdown, overheating, or electrical damage, rewinding restores full output at a fraction of the cost of a replacement alternator. Professional workshop service across Gauteng.
- Stator & rotor rewinding
- Wound to original spec
- Vacuum varnish impregnation
- Full load test before return
The Service
Professional Alternator Rewinding Across Gauteng
Generator winding failures are caused by thermal stress, moisture ingress, voltage spikes, mechanical vibration, or gradual insulation degradation over years of service. When windings fail, the first question is whether the alternator can be rewound or whether it should be replaced. That is decided on the unit, not from a percentage of a new alternator.
ProService Generator Repairs rewinds stator, rotor and excitation windings across Gauteng on alternators including Stamford, Leroy Somer, Mecc Alte and Marathon. An unlisted alternator is assessed on the unit. Not every winding failure justifies rewinding, and the assessment is given before the work is approved.
Our rewinding process follows original manufacturer specifications in every respect — wire gauge, insulation class, winding pattern, and connection configuration. Deviation from specification produces an alternator that either underperforms or runs hot, reducing service life. The core is cleaned and inspected for lamination faults and slot damage before new windings are installed, ensuring the foundation is sound before work begins.
Once wound, every unit is vacuum impregnated with varnish and oven-cured. This process fills all voids in the winding and provides long-term protection against moisture ingress, contamination, and thermal stress — the same causes that led to the original failure. Skipping this step leaves rewound windings vulnerable to the same failure modes within a short period.
Testing after rewinding is comprehensive. Insulation resistance, winding resistance, and high-potential testing are completed before the unit is reassembled. After reassembly, a full load test confirms the alternator meets its original rated output specification. The unit is not returned to service until every test is passed.
Winding failure on your generator?
Call to discuss rewinding options and get an assessment.
Signs of Winding Failure
When Does a Generator Need Rewinding?
01
No or low output voltage
Engine runs normally but the alternator produces no voltage or significantly reduced voltage. Stator winding open circuit or partial winding failure.
02
Insulation resistance failure
Megger testing reveals insulation resistance below acceptable limits — a reliable early indicator of winding degradation before catastrophic failure occurs.
03
Burning smell or visible damage
Burnt insulation odour, discolouration of windings, or visible scorching inside the alternator housing. Often follows an overload event or sustained overheating.
04
Reduced power output
Generator output falls short of its rated kVA. Partial winding failure causes the alternator to produce less than its design capacity under full load.
The Rewinding Process
How a rewind is carried out
- 01
Assessment & viability testing
Insulation resistance, winding resistance, and visual inspection determine whether rewinding is viable and cost-effective against the value of a replacement alternator.
- 02
Strip & core inspection
Old windings are stripped and the core is cleaned and inspected for physical damage, lamination faults, or slot damage that would affect the rewound unit's performance.
- 03
Rewinding to specification
New coils are wound using quality enamelled copper wire to original manufacturer specification — correct gauge, insulation class, winding pattern, and connection configuration.
- 04
Vacuum impregnation & curing
Completed windings are vacuum impregnated with varnish and oven-cured, providing long-term protection against moisture, contamination, and thermal stress.
- 05
Testing & load verification
Insulation resistance, winding resistance, high-potential testing, and a full load test confirm the rewound unit meets original output specifications before return to service.
Rewind vs Replace
Rewinding Is Often the More Economical Choice
On larger generator sets, alternator replacement is a major cost. A quality rewind — done correctly to original specification — delivers the same service life as a new unit while costing significantly less. For industrial and commercial generators where downtime has a direct financial impact, rewinding also offers faster turnaround than sourcing and fitting a replacement alternator, particularly for less common makes and frame sizes.
We assess each unit honestly. Where the core is damaged, where the alternator is beyond economic repair, or where a replacement unit represents better value for the customer's situation, we say so. The assessment is provided before any commitment to rewinding costs.
All alternator makes
Stamford, Leroy Somer, Mecc Alte & more
Honest assessment first
Viability confirmed before cost committed
Factory specification
Wire gauge, class & pattern matched
Warranted workmanship
Covered against materials & labour defects
Google reviews of ProService Generator Repairs
Google Review
Instead of writing off our burnt alternator, their rewinding division stripped the stator, re-wound the heavy copper coils, and baked it to factory specs for a massive cost saving.
Google Review
Exceptional heavy electrical rewinding services.
Common Questions
Generator rewinding — questions
When does a generator need rewinding?
When tests show a winding or insulation fault, not merely because voltage is missing. The AVR, breaker and excitation are checked first. Many no-power faults never become a rewind.
Can an alternator produce no power while the engine runs?
Yes. That pattern is electrical. It can be the AVR, the breaker, excitation or the windings. The engine being healthy does not prove the alternator is healthy.
Do you rewind Leroy-Somer alternators?
Leroy-Somer machines are assessed on the Leroy-Somer alternator page. A rewind is recommended only when the tests support it. Leroy-Somer is not treated as a diesel engine brand.
What are signs of an alternator winding fault?
No output, very low output, or a set that trips as soon as load is applied can point at the windings after the AVR has been ruled out. Burning smell or obvious damage is noted, and it is not assumed.
Can bearings be part of an alternator visit?
Yes, when there is noise or mechanical play at the alternator end. A bearing symptom is written separately from a winding fault.
Is rewinding done inside the canopy?
Usually not. If the alternator has to leave the set, that is explained before it is removed. Many electrical faults are still diagnosed on site.
Still unsure what the fault is? Call or WhatsApp 082 057 4605 for onsite diagnosis.
Service Areas
Generator rewinding across Gauteng
Generator rewinding services are available across all Gauteng areas including Johannesburg, Pretoria, Sandton, Midrand, Centurion, Randburg, Roodepoort, Kempton Park, Boksburg, Benoni, Germiston, Alberton, Fourways, and surrounding regions.
Get Started
Need Generator Rewinding?
Call to discuss rewinding options for your alternator. We assess viability honestly before any cost is committed — across all of Gauteng.
- Call
- 082 057 4605
- Message us on WhatsApp