Standby generators are there for us when we need them most in the event of a power failure… at least that’s what we hope. A generator, like any other piece of machinery, cannot be 100% trustworthy. This blog will look at some of the most typical reasons why a Diesel Generator may fail to start, as well as how to reduce the risk of failure.
Since standby generators are often used, monthly checks and service plans are essential to ensure that problems do not arise that the operator is aware of. Let’s look at the most common reasons why a generator won’t start and what you can do to prevent this from happening again.
1. Battery Failure
A battery failure is one of the most common reasons for a generator not starting. A sulfation build-up or a loose connection are two likely reasons (a build-up of lead sulphate crystals on the plates of lead-acid batteries). When the sulfate molecules in the electrolyte (battery acid) are deeply discharged, a build-up forms on the plate, prohibiting the battery from delivering enough current.
A battery failure can also be caused by an open inoperable charger breaker, which is frequently caused by a malfunction within the battery charger unit itself or by a tripped circuit breaker cutting the AC supply. This occurs frequently after a servicing or maintenance procedure has been completed and the charger has been turned off and not turned back on. It’s always a good idea to double-check the generator system after a service or maintenance to make sure the charger supply circuit breaker is in the appropriate location.
Finally, a dirty or loose connection could cause a battery to fail. Connections must be cleaned and adjusted on a regular site to prevent failure.
At Power Generation Enterprise we recommend you replace your batteries every three years to reduce the risk of failure.
2. Low Coolant Levels
An engine would quickly overheat without radiator coolant, likely to result in mechanical failure and engine failure. Coolant levels should be checked on a regular basis, and any puddles of coolant should be visually checked. The colour of the coolant varies depending on the manufacturer, but it is most commonly red.
Low coolant level shutdowns can also be caused by internally plugged radiator cores. When the generator is under load, the thermostats open completely when the engine reaches the ideal operating temperature, preventing the radiator from receiving area flow through the core. The coolant escapes through the overflow line because it has to go somewhere. When the engine cools down and the thermostat closes, the level drops, forcing your generator to shut down due to a low coolant level. Because this occurs only when the generator achieves its ideal operating temperature while under load, it is suggested that you test your generator with an external load bank to reach the temperature required to open the thermostats.
3. Bad Fuel Mix
Frequently, the inability of your generator to start is due to a lack of fuel. A faulty fuel mix can occur in a number of ways
- Your engine receives air but no fuel when your fuel runs out.
- When the air inlet becomes clogged, there is fuel but no air.
- It’s possible that the fuel system is adding too much or too little fuel to the mix. As a result, combustion within the engine does not take place properly.
- Finally, contaminants in the fuel (such as water in the fuel tanks) may prevent the gasoline from burning. This is common when fuel has been lying in a tank for an extended period.
It is usually best practice to test the fuel as part of a normal service of any standby generator to ensure that it does not cause an issue in the future.
4. Controls not in Auto
The “Not in auto” message on your control panel is the result of human error, usually owing to the main control switch being left in the off/reset position. In the case of a power outage, the generator may not start if it is in this position.