Cummins Diesel Generator Repairs & Servicing

Most Cummins callouts start the same way: the set passed its monthly test, then failed on the night the grid went down. We split the job into engine, starting circuit, fuel delivery, shutdowns, cooling, controller and electrical output, so you pay for the part that actually failed. ProService Generator Repairs services and repairs Cummins generators.

We read capacity from the data plate on site rather than from the badge, because two Cummins sets with the same canopy can carry very different engines and alternators. If your Cummins runs on natural gas, book Cummins gas generator repairs instead.

A Cummins service covers oil, filters, coolant, belts where the engine uses them, the battery charger and a read of the controller alarms. We set the interval from your operating hours, the duty and the Cummins schedule for that engine.

Low hours do not mean a healthy set. A standby Cummins that barely runs still ages its battery, lets diesel go stale and builds up cooling and control faults between outages, so we check all of them at every service.

A Cummins diesel usually fails to start because of the battery, the starter, a controller shutdown, an emergency stop, a low-fluid inhibit, a fuel solenoid or fuel that is not reaching the engine. Blocked filters and air in the fuel system are common on sets that stand between outages.

The cranking sound tells us where to start. No crank points to the battery, starter or controller. A strong crank with no fire points to fuel delivery, a shutdown or the injection side, and we test those two paths separately.

Controllers: we read Deep Sea, SmartGen and other panels exactly as they display, and record warning, shutdown and failed-start states from the screen before anything is reset.

ATS: the common patterns are a generator that runs while the building stays on mains, or a start command that never arrives. We test the changeover safely; you should never open live switchgear yourself.

Cooling: for overheating we check coolant level and leaks, the radiator, airflow, the fan or belt where fitted, the load and the temperature alarms on that installation.

Output: once the engine runs steadily, we check the breaker, wiring, AVR, excitation, engine speed, alternator and connected load in that order. Many Cummins sets carry a Leroy-Somer or Stamford alternator, and we follow the alternator plate for electrical parts.

Some Cummins sets start and idle perfectly, then lose speed, smoke, trip, overheat or give unstable power once the building load comes on. We compare how the set behaves unloaded and loaded before we name a part.

Your cost depends on the fault, the size and layout of the set, and whether the work is on the engine, fuel system, electrics or controller. As a guide, an AVR replacement typically runs R2,200 to R9,000 and controller repair or reprogramming R3,500 to R14,000. You get a written quote before any work starts.