The generator produces up to 400 V, and its cooling and exhaust systems run hot. Leave work on the electrical system, controls and a running engine to a technician. The tips below cover visual checks of a switched-off unit only.
Generator won’t start or stops right after starting
Usually fuel supply or low starter battery voltage.
Likely causes
- Air in the fuel system, clogged fuel filter
- Fuel pump or fuel solenoid not powered
- Low starter battery voltage, poor ground connections
- Controller, actuator or panel fault
What you can check
- Fuel level and fuel valve
- Starter battery voltage
- Fuses and breakers on the generator supply
- The message shown on the panel
When to call: When the engine cranks but won’t run, or the panel reports a control error.
Overheat shutdown (engine, exhaust, windings)
On marine generators the raw water flow is the usual suspect.
Likely causes
- Clogged raw water strainer (sea grass, shells)
- Worn or damaged water pump impeller
- Leaking water flow unit or heat exchanger
- Hot generator compartment, poor ventilation
What you can check
- Raw water strainer and seacock
- Water coming out of the exhaust while running
- Date of the last impeller change
When to call: When overheating returns after cleaning the strainer, or affects the alternator windings.
“Unexpected engine stop” — sudden shutdowns
The engine stops for no obvious reason, sometimes after hours of running or only under certain conditions.
Likely causes
- Interrupted fuel supply (filter, bleeding, pump)
- Corroded or partly blocked exhaust elbow
- Loose connectors, damaged wiring and sensors
- Output voltage out of range (“high voltage” message)
What you can check
- Whether stops depend on running time or load
- Condition of fuel filters and hoses
- Signs of corrosion and leaks around the exhaust
When to call: When stops keep happening — noting when they occur shortens the diagnosis.
Error 030 “Inverter Overtemp” and other inverter errors
The PMGi inverter shuts down on overtemperature — sometimes with no load, half an hour after starting.
Likely causes
- Faulty or dirty inverter fan
- Insufficient ventilation where the inverter is mounted
- Faulty temperature sensor or inverter electronics
- Issues on the alternator side and connections
What you can check
- Whether the inverter fan runs
- Whether air intake and outlet are blocked
- Temperature in the mounting space
When to call: When the error returns with a working fan — that needs an inverter diagnosis.
Overload warning or power drop
The generator doesn’t deliver rated power, or power sags after a few minutes.
Likely causes
- Loads with high inrush current (air conditioning, compressors)
- Inverter derating at high temperature
- Restricted air or fuel supply to the engine
- Alternator or inverter fault
What you can check
- Which loads run at the same time
- Whether the drop coincides with rising temperatures on the panel
When to call: When the generator can’t reach power under a reasonable load.
Engine runs but no AC output
The generator runs, but there is no 230 V at the output.
Likely causes
- Tripped breaker or blown main fuse
- Failed capacitors (asynchronous generators)
- Lost residual magnetism in the windings
- Inverter fault on i-series generators
What you can check
- Breakers and fuses on the AC side
- Inverter lights (FAILURE / OK)
When to call: Always — measurements and work on windings and capacitors need a technician.
Oil pressure alarm
The alarm appears after long running or returns minutes after restarting.
Likely causes
- Low or wrong oil
- Faulty sensor or its wiring
- Engine overheating
- Oil pump problem
What you can check
- Oil level on a cold engine
- Whether the alarm comes with high temperature
When to call: If the oil level is correct and the alarm returns — don’t keep restarting the generator.
Water leaks and exhaust elbow corrosion
Water in the generator tray, salt or rust around the exhaust, bilge sensor triggered.
Likely causes
- Corroded exhaust elbow (water injection)
- Leaking water flow unit or water pump
- Worn hoses and clamps
What you can check
- Salt and rust around the exhaust and water pump
- Water collecting in the generator tray
When to call: Immediately — a leaking exhaust can flood the engine.
Blank or resetting panel screen
The panel goes dark, restarts or shows random messages.
Likely causes
- Low control supply voltage
- Loose or corroded connectors
- Damaged panel cable or control board
What you can check
- Battery voltage
- Panel cable connectors
When to call: When it happens with a healthy battery.
V-belt, impeller, filters — when to replace
Many failures start with a skipped service.
Likely causes
- Worn alternator or pump drive belt
- Hardened impeller
- Clogged fuel and air filters
What you can check
- Running hours since the last service
- Date of the last impeller change
When to call: Before the season or per the manufacturer’s intervals — we’ll match a service kit to your model.
Not sure what’s wrong with your generator?
Call with the panel message — we’ll make a first assessment and tell you whether a service visit is needed.
