Generator maintenance
Ongoing Generator Maintenance Across Gauteng
A generator maintenance plan is an ongoing, agreed schedule of services, inspections, test runs and load tests that keeps a generator ready to start and carry its load all year, with a record of every visit. It is not the same as a single service visit: the plan decides when services happen, what is checked between them and how the generator is exercised. We build each plan around how the generator is actually used, from a home standby set that seldom runs to a factory set carrying the site through load shedding.
- Plans for seldom-used standby sets, load-shedding duty and prime-power or critical sites
- Test runs, load tests, fuel, battery, coolant and changeover checks between services
- A running history for every generator, with faults quoted before any work
- Breakdowns between visits handled 24/7
Established 2006
20 years of experience
24/7 operations
We Arrive Within 1–2 Hours
(usually within 1 hour)
Free callouts and quotations
One-year warranty
Qualified and certified technicians
We Service & Repair All Generator Brands
All generator makes and models
1 kVA–20,000 kVA capability
A plan for the year, not a visit on the day
A generator service is one visit: oil and filters changed, the set checked and test-run on the day it falls due. A repair fixes a fault that has already stopped it. Maintenance is the plan that sits over both. It sets when each service falls due by running hours and by date, what is inspected between services, how and when the generator is exercised and load tested, and how every visit is recorded.
The point of the plan is to find the slow failures while the mains is still on: a battery losing capacity, a charger that has stopped charging, water collecting in the fuel tank, a changeover contactor wearing out. None of these shows on a normal day. Each one shows the moment the power fails, when there is no time to fix it calmly.
A maintenance contract is agreed in writing for each site, so the generators covered, the schedule and what each visit includes are clear from the start. Our terms cover anything the agreement does not.
South African context
How load shedding changed generator maintenance
Before load shedding, many standby generators in Gauteng ran only a few hours a year beyond their test runs. During the heavier stages, the same sets started two or three times a day, ran for hours on a fraction of their rating and were refuelled from containers between outages. Hours that once took years built up in months, and service intervals came round far sooner than the calendar suggested.
Outages do not stop when load shedding eases. Municipal faults, cable theft, substation failures and Highveld summer storms still cut the supply without warning, and a set that has stood idle for months is then expected to start instantly. A good plan is adjusted as the pattern changes, rather than set once and forgotten.
- More starts: more wear on batteries, starter motors and changeover contactors
- Light loads overnight: the conditions for wet stacking
- Frequent refuelling: more chances for water and dirt to reach the tank
- Long quiet spells: fuel ageing and batteries discharging unseen
An example of how quickly it adds up: two outages of two and a half hours a day put about 150 hours a month on the hour meter and about 60 starts on the battery, starter and changeover.
Built around use
Three ways generators are used, three kinds of plan
Standby sets that seldom run
A home, office or estate set that may go months without a real outage. Its risks come with time, not hours: fuel ageing in the tank, batteries discharging, coolant inhibitors weakening and seals drying out. The plan follows the calendar, with regular exercising, battery and charger checks, fuel inspection and a proven changeover, so the first real outage is not also the first test in a year.
Sets carrying load shedding or frequent outages
A set that starts most days and runs for hours. Here running hours set the pace: oil and filters reach their hour interval quickly, belts and hoses wear, the battery and starter work hard, and the changeover switches many times a week. The plan tracks the hour meter between visits, watches fuel quality after frequent refills and looks for wet stacking where the set runs lightly loaded overnight.
Prime-power and critical-site sets
Clinics, data and server rooms, cold rooms and factories, where a failed start costs far more than the generator. These sets may run for long periods or carry loads that cannot wait, such as a UPS with only minutes of battery behind it. The plan adds periodic load testing, closer trend records and a check on everything that must work in sequence: mains sensing, start, transfer and the run under load.
What each plan typically focuses on
| Focus | Standby set, seldom run | Load shedding or frequent outages | Prime power or critical site |
|---|---|---|---|
| Main risk | Standby set, seldom runAgeing: fuel, batteries, coolant and seals deteriorate while the set stands | Load shedding or frequent outagesWear: hours, starts and transfers build up quickly | Prime power or critical siteConsequence: a failed start or a trip under load stops something that matters |
| What sets the services | Standby set, seldom runMostly the calendar, with the hour interval as a backstop | Load shedding or frequent outagesMostly the hour meter, tracked between visits | Prime power or critical siteWhichever falls due first, hours or date, with agreed interim checks |
| Exercising | Standby set, seldom runRegular runs, with the building load where the site allows | Load shedding or frequent outagesThe outages exercise it; quiet spells are covered by test runs | Prime power or critical siteScheduled runs that prove the full sequence from mains failure to transfer |
| Load testing | Standby set, seldom runPeriodic, to prove the set can still carry its rated load | Load shedding or frequent outagesWhere it runs lightly loaded or shows signs of wet stacking | Prime power or critical sitePeriodic, to prove a sustained run at the load the site depends on |
| Fuel | Standby set, seldom runCondition checks and a plan to turn the stock over before it ages | Load shedding or frequent outagesWater and dirt from frequent refills; filters and water separator | Prime power or critical siteFuel quality, and enough stock on site for the runtime needed |
| Battery and starting | Standby set, seldom runCharge, charger output and terminal condition | Load shedding or frequent outagesBattery, starter motor and charge alternator under heavy cycling | Prime power or critical siteBattery condition trended visit to visit, charger alarms proven |
| Changeover | Standby set, seldom runProven on a simulated mains failure where safe and agreed | Load shedding or frequent outagesContactor and transfer wear from frequent switching | Prime power or critical siteMains sensing, timers and transfer checked as one sequence |
Not sure which pattern fits? The first visit establishes it from the hour meter, the controller’s event log and how the site uses power.
Test runs and load tests: proving more than a start
Most automatic controllers can exercise a standby set on a timer, and many are set to start it weekly and run it briefly with no load. That proves the battery, starter and controller, which is worth knowing. It does not prove the generator will carry the building, and a diesel engine run repeatedly with little or no load never gets hot enough to burn all its fuel.
Unburnt fuel and soot then build up in the exhaust and turbocharger, and carbon forms on the injector tips and valves. This is wet stacking: black, oily residue at the exhaust joints, smoke on start-up and, left long enough, glazed cylinder bores and rising oil consumption. A plan avoids it by exercising the set with real load where the site allows, for example during an agreed transfer test, and by keeping no-load runs short.
Where the building’s own load is too small to work the engine properly, periodic load bank testing fills the gap. The set is held at a controlled, measured load, without touching the site’s supply, long enough to show whether it can sustain what an outage will ask of it, and the hot run clears light-load deposits. Within a plan, the test is arranged and quoted as part of the agreed schedule, and is usually most useful for sets that normally run lightly or protect a critical load.
Fuel, batteries and coolant: failures that build up slowly
Diesel does not keep indefinitely. Condensation adds water to the tank as it warms and cools, microbial growth ("diesel bug") forms where fuel meets water, and sediment settles on the floor, all of it waiting for the fuel pickup. A plan includes checks for water and sludge, draining the water separator, and an agreed way of turning the fuel stock over so the set is not running on diesel that has sat for a year or more. Our guide to diesel fuel contamination explains the signs; where a tank, lines or injectors need cleaning or repair, the work is quoted under fuel system repairs.
The starting battery is one of the most common reasons a standby generator fails to start. Each visit checks its voltage and condition, the terminals, the battery charger that keeps it topped up from the mains and the engine’s charge alternator when the set runs. A charger that has failed quietly, or one charging at the wrong voltage, is easy to miss until the morning the battery is flat. The faults behind it are covered in battery not charging.
Coolant protects the engine from corrosion as well as heat, and its inhibitors weaken with age even when the set barely runs. Plans cover the coolant strength, hoses, the radiator core (often clogged with dust, grass and leaves in Gauteng yards), belts and, where fitted, the block heater that keeps a standby engine warm enough to start and take load quickly on a cold Highveld morning. Coolant and radiator care explains what owners can safely check with the engine cold.
Changeover
Proving the changeover, not assuming it
A standby generator is only as good as the panel that calls it. The controller must sense that the mains has failed, ignore brief dips, start the engine, let it settle and transfer the load; when the mains returns, it must wait until the supply is stable, transfer back and let the engine cool down before stopping. A fault in any step leaves the building dark with a perfectly healthy engine.
Where it is safe and agreed with you, maintenance visits simulate a mains failure so the whole sequence is proven. We check the mains sensing, timer settings, contactor or switch condition, interlocks and the controller’s event log, and look harder at contactors on sets that switched several times a day through load shedding. Faults are explained in changeover and ATS problems, and controller work is under control panel repairs.
- Mains-failure test by agreement, with the site prepared for the transfer
- Start, transfer, return and cool-down timers checked
- Interlocks and contactors inspected, never bypassed
Faults a maintenance visit catches early
| Symptom | Likely causes | Repair route |
|---|---|---|
| Oil level falling between visits | Likely causesLeaks at seals, gaskets or the sump plug; oil burnt by worn rings, valve stem seals or light-load running; a turbocharger seal passing oil | Repair routeLeaks |
| Low oil pressure warnings in the event log | Likely causesLow oil level, oil thinned by fuel dilution, a blocked filter, the wrong oil grade, a faulty pressure sender or internal wear | Repair routeLow oil pressure shutdown |
| Coolant running hotter than last time under similar load | Likely causesA radiator core clogged with dust, a slipping fan belt, a sticking thermostat or weak coolant | Repair routeOverheating |
| Slow or hard starting on a cold morning | Likely causesA weak battery, glow plugs or the block heater not working, air in the fuel, worn injectors or a tired starter motor | Repair routeGenerator not starting |
| Voltage drifting or dipping when load is applied | Likely causesAn AVR fault, exciter or rotating diode problems, loose sensing wiring, or a governor slow to respond | Repair routeAVR repairs |
| Frequency hunting on the test run | Likely causesA governor or actuator fault, a speed pickup problem or a restriction in the fuel supply | Repair routeFrequency and speed problems |
| Black smoke or oily residue at the exhaust | Likely causesOily residue: light-load running (wet stacking). Black smoke: overloading, a blocked air filter or injectors that need testing | Repair routeGenerator smoke |
A running history for every generator
Each visit adds to one record per generator, so trends show before they become failures. A dated history also helps when an insurer, auditor, landlord or body corporate asks how the backup power is looked after.
- Date, hour-meter reading and the work done, including parts and fluids fitted
- Test-run readings: voltage and frequency, oil pressure, coolant temperature and battery voltage
- Alarms and events from the controller’s log since the last visit
- Fuel level and condition, and any water drained
- Changeover test results, where a test was agreed
- Faults found, with the quotation and whether the work was approved
- When the next service falls due, by running hours and by date
A maintenance record shows what was done and found. It is a record of work, not a compliance certificate.
One plan across several generators or sites
Businesses rarely have just one set to think about. A retail group may have a generator at each branch, a body corporate one per block, a factory a production set and a smaller one for its offices. A single schedule across all of them, with records kept per generator, makes due dates visible and stops one site being forgotten.
For business continuity, the question is not whether the generator ran last month but whether it will carry the critical load the next time the supply fails, for as long as it is needed. That depends on fuel on hand, the changeover working first time, and whether the set still has enough kVA for loads added since it was installed (our kVA sizing guide explains the arithmetic). A plan keeps all three under review. Sector detail is on our commercial, industrial and home generator pages.
Process
How a maintenance plan is set up
- 01
Assessment
We look at each generator: its age, hours, installation, controller settings, how critical the load is and how it has been used through outages. Free callouts and quotations.
- 02
Agree the plan
Service intervals, inspections, test runs, load tests and fuel checks are set for each generator and confirmed in writing.
- 03
Baseline visit
The first visit brings the generator up to date, sets the starting point for its records and lists anything that needs attention, quoted separately.
- 04
Scheduled visits
Visits follow the agreed schedule. Each adds to the generator’s history, and faults found are quoted before any work.
- 05
Review as things change
When outages increase, loads are added or a set moves to more critical duty, the schedule is adjusted rather than left as it was.
Maintenance visits across Gauteng
We maintain generators on site throughout Gauteng, so nothing has to be transported. Plans cover homes, estates, offices and plants across Johannesburg, Pretoria and Centurion, Ekurhuleni and the East Rand, the West Rand and the Vaal Triangle.
The work changes with the area: office parks, data rooms and estates around Sandton, Midrand and Centurion; factories, warehouses and cold stores in the industrial areas around O.R. Tambo and Isando; smallholdings with borehole pumps towards Muldersdrift on the West Rand; and industrial sites in Vereeniging and Vanderbijlpark. Each plan reflects what the generator protects.
Every make, controller and type of generator
We Service & Repair All Generator Brands. That means one plan can cover a mixed fleet: a standby set with a Perkins or Cummins engine, another built around a Stamford alternator, and controllers from Deep Sea Electronics, ComAp or SmartGen. Each plan follows that set’s own engine manual and service intervals, not a generic list. See all the generator brands we work on.
Most plans are for diesel generators and standby sets with automatic changeover. Gas generators used for home backup, and petrol or portable and inverter units kept for outages, also benefit from a schedule: petrol units especially, because stale fuel in the carburettor is the usual reason they will not start after months in a garage.
FAQ
Frequently asked questions
How is a maintenance plan different from booking a generator service?
A service is a single visit when the generator is due: oil, filters, checks and a test run. A maintenance plan is the ongoing arrangement that schedules those services, adds inspections, test runs, load tests and changeover checks between them, and keeps a history of every visit. If a service when you remember to book one is enough, book a service; if the generator must be ready every time, a plan is the safer choice.
How often will you visit, and is it a contract?
Visit frequency is agreed for each generator from the manufacturer’s schedule, its running hours, its age and how critical the load is, so a seldom-used home set and a clinic’s standby set will not have the same plan. The plan is confirmed in a written agreement, and the schedule can be changed if the way the generator is used changes.
Is a maintenance plan worth it for a home standby generator?
It depends on how much the household relies on it. For a home set used only in occasional outages, a yearly service with a test run may be enough. If the house depends on it for security, a borehole pump, medical equipment or working from home, a plan that also checks the battery, fuel and changeover between services is worth considering. See home generator services.
Our generator runs lightly loaded during load shedding. Can maintenance prevent wet stacking?
It can reduce it a great deal. The plan looks for the early signs, keeps no-load test runs short, exercises the set with real load where possible, and includes periodic load bank testing where the set normally runs well below its rating. If the generator is badly oversized for its load, we will tell you.
Can you take over a generator someone else used to maintain?
Yes. We Service & Repair All Generator Brands. The first visit is a baseline inspection that records the generator’s current condition, so the plan starts from the facts rather than old paperwork. Share any previous service records you have.
What happens if a visit finds a fault?
We explain what we found and why it matters, and give you a free quotation. Nothing is repaired without your approval, and anything that could stop the generator is flagged as urgent.
What if the generator fails between visits?
Call us at any hour: we operate 24/7. We arrive within 1–2 hours, usually within 1 hour. A breakdown is handled as an emergency generator repair, and the generator’s visit history helps the technician find the cause faster.
Will your maintenance records satisfy our insurer or auditor?
They give a dated history of every visit, the readings taken, the tests run and the faults found and fixed. That history shows how the generator has been looked after, but it does not certify compliance with anything, so check with your insurer or auditor what they require; where it is something we can record at each visit, we will include it.
Related pages
Related services
Related generator problems
Related brands
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