When used as a primary or backup power source,
industrial diesel generator sets are bound to experience malfunctions. Generally speaking, there are many reasons for diesel generator set failures.
Low Coolant Level Alarm/Shutdown
The most obvious cause of a low coolant level is an external or internal leak. While many industrial diesel generators are equipped with alarms, dedicated low coolant alarm indicators are rare. Typically, this alarm is caused by a shutdown due to excessively high coolant temperature. If your generator is equipped with a "High Coolant Temperature Approach Alarm" or "High Coolant Temperature Warning," you can confirm the cause of the shutdown.
Leaks – Oil, Fuel, or Coolant
Leaks can be effectively prevented through regular routine maintenance. In most cases, an oil leak is not a true leak, but rather a result of "wet buildup." Wet buildup refers to the accumulation of carbon particles, unburned fuel, lubricating oil, condensed water, and acid within the exhaust system.
The most common coolant leak occurs at the heater hose in the engine block. Due to the extreme temperatures generated by the block heater, this can cause the heater hose to fatigue more quickly.
The most common fuel leak service call is due to overfilling the base tank. This is often caused by human error or a malfunction in the pump system. To prevent this, it is always recommended that you have your industrial diesel generator refueled by a trained professional.
Cylinder Block Heater
The cylinder block heater actually heats the coolant circulating around the engine block. Keeping the engine block warm prevents the oil from becoming too thick in cold temperatures.
A common misconception is that engines don't need a heater in warm climates. A cylinder block heater does more than just help the engine start smoothly in cold weather. Due to the different metals used in the engine, accelerated wear can occur during the starting process. Pistons, typically made of aluminum, expand more quickly than iron cylinder liners. This rapid expansion of the piston can cause wear on the piston skirt.
A cylinder block heater reduces much of this wear by maintaining the cooling system's temperature and limiting cylinder liner expansion.
Low Coolant Temperature Alarm
A low coolant temperature alarm is primarily caused by a malfunctioning heater block. These heaters operate 24/7 and frequently fail. However, block heaters do not cause an engine to fail to start. The high temperature inside the block heater drives the coolant through the system. Sometimes, you can hear the coolant boiling inside the block heater.
Fuel Backflow into the Tank/Generator Fails to Start
This is a common problem with newer engines that are not used regularly. To meet today's emissions regulations, tolerances within the fuel system are tighter, making the fuel system more susceptible to air that can affect the generator's starting ability. This is less common in older generators. Older industrial diesel generators experiencing this problem may have leaks in the piping or check valves, preventing them from effectively retaining fuel within the engine.
Non-Automatic Control
Industrial diesel generators are equipped with a control panel. This panel controls all aspects of the generator's setup, operation, and shutdown. It displays all critical engine and alternator information and indicates any "faults" that cause it to shut down the generator. 99% of generator control service failures are classified as "non-automatic" and are a direct result of human error.
The obvious cause is that the master control switch is in the "off/reset" position. Control switches may have multiple positions, such as "Off/Reset" and "Cooling," which can prevent an industrial diesel generator from starting during a power outage. These positions should sound an alarm.
Failed alarms, tripped circuit breakers, unreset switchgear, and activated emergency stop buttons are all examples of non-automatic faults. Several generators are configured to short-circuit the main circuit breaker during an emergency shutdown. When an industrial diesel generator shuts down on its own (for any reason), someone must physically reset the control panel to clear the alarm.
Engine Running Out of Fuel
Mechanical fuel level gauges may not always be accurate. Unlike mobile vehicles that can utilize a larger tank capacity, a generator's fuel tank is stationary, causing fuel to stagnate. Mechanical gauges may also become fixed in position until vibration dislodges them. Some industrial diesel generators are equipped with a "low fuel level shutdown" or "critical fuel level shutdown." When the fuel is nearly depleted, the control panel automatically shuts down the generator to prevent air from being drawn into the fuel system.
Tripped circuit breakers unrelated to the generator
This service hotline is typically addressed with the message "We have a power outage and the generator failed to start." First, make sure no one has accidentally pressed the remote "Emergency Power Off" switch.
During a power outage, check the automatic transfer switch. The ATS should be equipped with a light or display to indicate the switch position and the availability of the signal source. Never attempt to manually operate the automatic transfer switch if you do not know how to do it correctly.
