industrial generator behind a building

This article describes the three most common standby generator problems and how to fix them. Read more to ensure your generator is in top running condition.

1. Cooling System

What is the Cooling System?
It’s the system that maintains the specified operating temperature of the engine to ensure that the engine does not overheat, but achieves maximum performance.

What are some of the malfunctions/failures that commonly occur with cooling systems? 

  • Coolant breaks down and becomes acidic over time which reduces lubrication and protection qualities. When this happens the radiator can internally corrode and often causes rot from the inside, out. Once there is visible leaking from the radiator, the damage has been done and it is too late to remedy.
  • Hoses become hard and brittle over time which will cause hoses to rupture under stress such as during extended run times (outages).
  • Water pump o-rings and seals harden and begin to leak which will cause the water pump to fail. When
    the water pump fails, there is large coolant loss which typically requires labor intensive cleanup and an
    inoperable generator until the water pump and any residual damage, is rectified.
  • Block heaters fail which means the generator engine will struggle to, or won’t start in cold weather

What are signs of a potential cooling system malfunction?

  • Visible leaks
  • Discolored, corroded area around coolant connections

What we recommend to prevent malfunction/failure:

  • Periodic coolant change performed every three to five years
  • Cooling system flush if the system has been neglected

2. Wet Stacking

What is Wet Stacking? 
Wet Stacking is the accumulation of unburned fuel on a diesel engine. This occurs when the engine runs lightly loaded or unstressed.

Why is it important to pay attention to this?
Wet stacking can cause exhaust restriction, fuel injector damage, lubrication oil contamination, piston & piston ring damage

What are signs of wet stacking?

  • Sludge or tar-like substance coming from the exhaust pipe
  • Black smoke upon the generator starting

What we recommend:
If there are visible signs of wet-stacking we would recommend having a minimum of a two hour load bank performed. Load banking is when an artificial load equivalent to the capacity of the generator is placed on the generator. In the case of wet stacking, the intent is to get the generator running at a high enough temperature to burn the unburned diesel out of the exhaust, removing any restriction.

3. Contaminated/Degraded Diesel Fuel

There are several scenarios which lead to the contamination and degradation of a generator’s diesel fuel:

  • Condensation and ultimately water, due to fluctuations in outdoor temperature
  • Rust from the aging of the fuel storage tank due to the presence of moisture
  • Microbial growth-moisture provides adequate growing environment and creates fine particulates in
    the fuel

Why is it important to pay attention to this?
All of the “junk” just described usually settles to the bottom of the fuel storage tank. The generator operates as it should during its weekly exercise cycle and may even run for the occasional short power outage. The real problems occur when the generator is called upon to run for an extended period of time and/or once the fuel level decreases enough that the  generator starts ingesting the “junk” that has settled to the bottom of the tank.

What are signs of contaminated diesel fuel?
No visible signs other than knowing that the fuel has been sitting for a period of time (more than 2 years)

What we recommend to diagnose and/or rectify:

  • Fuel Sampling: a simple and inexpensive test of the diesel fuel where samples from the top, middle and
    bottom of the tank are collected. The samples are sent to a third party lab who analyzes the fuel and
    provides a comprehensive analysis of whether fuel polishing and/or additives should be utilized in order
    to restore the diesel fuel to a useful state. We recommend having fuel sampling performed every year.
  • Fuel Polishing: termed “dialysis for diesel”, fuel polishing is a means of filtering out the impurities of the diesel fuel to restore the fuel to a “clean” state.
Want to learn more about how to prevent generator failures at your facility?
Give us a call and we would be happy to discuss any of your concerns!