Generator brands · Mobile and site sets
Repairs and Servicing for Atlas Copco Site Generators
We repair and service Atlas Copco generators on site across Gauteng, from towable QAS units on construction and mining sites to skid-mounted QES sets used for standby and hire. These sets are built to move, so most faults come from transport, dust, site refuelling and long running hours, and we check the engine, alternator, controller, sockets and protection together.
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
How a site generator lives differently from a standby set
A standby set sits on a plinth and runs a few hours a month. A QAS set may run all day for weeks on a construction or mining site, then be towed over gravel to the next job. Vibration loosens connections, dust loads the air filter and radiator, and refuelling from drums and bowsers brings in water and dirt.
Atlas Copco designs for this: many models have a fluid-containing base frame, a lifting eye and a three-way valve for an external fuel tank. Each feature needs its own checks: a frame full of rainwater no longer contains a spill, and a valve left in the wrong position can starve the engine. Where the set feeds tools directly through its own sockets, its earth leakage protection, output breaker and earthing must work at every site, not just the first.
Engines, alternators and controllers in Atlas Copco sets
Atlas Copco builds the set, canopy and controls around an engine from a specialist maker: compact water-cooled diesels such as Kubota engines in the smallest units, larger industrial diesels from several makers in the bigger frames. The engine decides the oil grade, filters and service schedule, so we go by its own data plate rather than the set model.
The alternator is a brushless machine with an AVR. Control is usually by an Atlas Copco Qc-series controller: basic versions start and protect the set, more capable ones add automatic starting on mains failure and, on some, running sets in parallel.
The photo shows a typical canopied diesel set, not an Atlas Copco unit, with the same arrangement of engine, alternator and controller in one enclosure.
Checks after a move or a hire period
When a set comes back from hire or arrives on a new site, we work through these checks before it carries load again. Operators can look for damage and leaks; earthing, protection and fuel-system items are technician work.
- Tow hitch, axle, wheels, tyres and lifting eye in sound condition
- No fuel, oil or coolant leaks after transport; base frame drained of rainwater
- Three-way fuel valve set for the tank actually in use
- Air filter restriction indicator read, and radiator fins clear of dust
- Water drained from the fuel water separator
- Battery secure and its terminals tight
- Output breakers and earth leakage protection tested
- Earth connection made at the new location
- Sockets, covers and cables undamaged
If a set is shared between sites or operators, keep a simple log of hours, refuelling and faults.
Typical site faults
| Symptom | Likely causes | Repair route |
|---|---|---|
| Will not start after transport | Likely causesLoose battery or wiring connection, fuel valve position, air in the fuel | Repair routeGenerator not starting |
| Earth leakage trips when tools are plugged in | Likely causesDamaged cables or tools, water in sockets, an earthing fault | Repair routeShutting down or tripping |
| Loses power in dusty conditions | Likely causesBlocked air filter or radiator, overheating | Repair routeOverheating |
| Smoke and poor running after refuelling | Likely causesWater or dirt in the fuel from drums or cans | Repair routeFuel system repairs |
| Oily black exhaust after weeks on a light load | Likely causesA large hire set running a few site cabins, unburnt fuel building up | Repair routeWet stacking |
| Voltage drops when large tools start | Likely causesOverload, motor starting currents, long cable runs | Repair routeVoltage problems |
Service focus by the work the set does
| Duty | What builds up | What a service focuses on |
|---|---|---|
| Prime power on a construction or mining site | What builds upRunning hours, dust, vibration | What a service focuses onHour-based oil and filter changes, air filter, radiator cleaning, mountings and connections |
| Events and short hires | What builds upMoves, many operators, short runs | What a service focuses onAfter-hire checks, sockets and cables, earth leakage tests, fuel quality |
| Standby at a building (often a QES set) | What builds upTime rather than hours, light test runs | What a service focuses onA yearly service, battery and charger, coolant, and a run under real load or a load bank test |
| Parked between jobs | What builds upBattery drain, condensation in the tank | What a service focuses onBattery care, draining water from the fuel, a test run before it goes out |
Parts for Atlas Copco sets
A site set is really three products in one frame, so parts come from three places. Filters, belts and engine spares are chosen by the engine’s own model and serial number; rotating diodes, bearings and the AVR by the alternator plate. The quote says whether each part is genuine or a quality equivalent built to the same specification. Items only Atlas Copco uses, such as canopy panels, socket boxes and controller parts, are identified from the set’s nameplate and usually take longer to arrive, which matters if the set is due back on a job.
For a fleet of site sets, planned maintenance by running hours beats waiting for faults, and both servicing and repairs are done where the set is working.
Independent service
We Service & Repair All Generator Brands
Onsite Generator Repairs is an independent generator specialist. We repair, service and maintain Atlas Copco equipment as part of our work on every make of generator.
Manufacturer warranty claims go through the manufacturer’s own network. If your generator is still under warranty, check the warranty terms before arranging work by anyone else.
Brand names and trademarks belong to their respective owners. Onsite Generator Repairs is an independent service and repair company.
Service areas
Where we work in Gauteng
FAQ
Frequently asked questions
Can you service a hired Atlas Copco generator?
If the generator is hired, the rental company is usually responsible for its servicing and repairs, so check the hire agreement first. We can help where you own the set or the rental company agrees.
Why does the earth leakage keep tripping on my site generator?
Usually because of a damaged cable, a wet socket or a faulty tool rather than the generator. Unplug everything, reset, and reconnect one item at a time. If it trips with nothing connected, the fault is in the set and needs a technician.
Can a QAS set be used as standby power for a building?
It can, with a controller that supports automatic starting and a properly installed changeover panel. That is electrical installation work; see generator installation.
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