Why Most Electrical Cabinet Cooling Fans Fail


Valuable electrical equipment housed inside cabinets is typically protected by some type of thermal management system to maintain safe operating temperatures. The electrical cabinet is designed to keep out dust, dirt and water but overheating is one of the single largest threats facing the electrical components leading to potential malfunctions, failure and unplanned costly downtime.

To prevent components from thermal damage inside an electrical cabinet, cooling fans are often the most cost effective method used as long as the ambient air temperature is well below the maximum operating temperature of the electrical components. Cooling fans can be a good choice to keep electrical components safe but only under certain conditions.

Operating Conditions Causing Cooling Fan Failure

Electrical cabinet cooling fans exposed to excessive amounts heat and dirt fail at a rate much greater than those operating under normal conditions. A dirty air filter can damage the fan motor by blocking the air flow causing the internal motor temperature to rise. A fan motor operating above the ideal design temperature will cause the bearing to rapidly lose lubricating properties.

Fan motors containing high quality ball bearings are more efficient and last much longer than ordinary sleeve bearings. Motors exposed to operating temperatures above 90°F (32°C) and equipped with ball bearings can provide a reasonable service life. At these temperatures a sleeve bearing fan will quickly fail due to the loss of lubrication.

How Electrical Cabinet Cooling Fans Fail

Cooling fans fail gradually over time due to aging and wear. Some larger slower turning fans last longer than other smaller high speed types but usually fan failure is a gradual process and not an abrupt one. As cooling fans age they gradually begin to slow down due to increased internal resistance reducing the airflow rate into the electrical cabinet. Less airflow increases the chances for the sensitive costly components to overheat.

Under these circumstances electrical cabinet overheating may be difficult to diagnose unless a fan motor bearing makes loud noises while in operation indicating imminent failure.

Ways to Reduce Cooling Fan Failure Rate

Electrical cabinet cooling fans are more susceptible to failure than any other component because the motors are under stress due to constant operation. Keeping air filters clean with routine maintenance will allow the cooling fan to operate normally, providing constant airflow to both the fan motor and the components inside the electrical cabinet.

Ensuring the ambient air temperature is well below the electrical components’ maximum allowable temperature will also help reduce cooling fan failure.

If Routine Maintenance Doesn’t Keep Things Cool

Regular filter maintenance will help keep your electrical cabinet cooling fans running efficiently. However, if after routine maintenance overheating problems continue, it may be time to re-evaluate your cooling system. Cooling fans equipped with high quality ball bearings may be the answer.

Electrical cabinet cooling fans are available in various sizes and types to suit the application. Selecting the correct size for your application will help ensure the system sufficiently cools the electrical cabinet with minimal interruption. Proper fan sizing is also important for maintaining energy efficiency and for electrical component cooling.

If your existing cooling fans are causing problems, call the experts at Thermal Edge today help you select the right cooling equipment for your application.