Foolproof Method for Calculating Heat Dissipation in Control Panels

Foolproof Method for Calculating Heat Dissipation in Control Panels

As electrical components become increasingly smaller and are more densely packed into electrical control panels, the amount of heat generated inside cabinets continues to increase. When considering heat dissipation in control panels it’s important to note what electrical equipment manufacturers specify as a maximum allowable operating temperature for their components.

Maintaining a maximum internal control panel air temperature of 95°F (35°C) helps promote higher operating efficiencies and longer electrical component life. It’s easy to overlook the importance heat dissipation plays in control panels and how it can affect electrical equipment reliability.

How Heat Dissipation Works in Sealed Unvented Control Panels

In order to protect against demanding environmental conditions most industrial applications will require sealed unvented control panels such as NEMA Type 12, 4, and 4X cabinets to protect the costly electrical components housed inside. Most applications will require a closed-loop cooling solution due to high ambient temperatures or to protect sensitive electrical components from excess dust and dirt.

While the heat producing electrical components increase the air temperature inside the control panel, the resulting heat is transferred through the walls of the cabinet to the cooler ambient air outside where heat dissipation occurs. If the ambient air were cold enough to maintain temperatures below maximum operating temperature for the electrical components, this would be a natural cost effective cooling solution, but this is rarely a viable option.

The overall cooling capacity needs to match or exceed amount of total heat load generated by the electrical equipment within the control panel when the ambient air temperature is lower than the cabinet air temperature.

How Heat Dissipation Relates to Control Panel Size

Besides ambient temperature, the physical size of a control panel is the primary factor in rate of heat dissipation. Larger control panels will have larger exterior surface areas, resulting in a lower temperature rise from the heat producing electrical components inside. Having an oversized control panel simply to increase the heat dissipation rate doesn’t make economic sense, since larger cabinets are more costly and may require excessive space.

The easiest method to calculate the surface area of the control panel is to use the following equation: Total Surface Area = 2(H x W) + 2(H x D) + 2(W x D), which includes all six sides of the control panel measured in feet. Any surface area not exposed to ambient air, such as wall mounted or free standing cabinet models without legs, must be subtracted from the total value.

Once the total surface area has been determined, the next step is to calculate the heat load produced by the electrical components.

Factoring in Heat Load Produced by the Electrical Components

The total heat load is established by adding together the heat dissipation of all individual components housed inside the control panel. This information can be obtained from the manufacturers of the electrical components and the resulting value is usually given in Watts.

Additional Heat Dissipation Factors to Consider

Although the heat dissipation calculation of a control panel is a simple one, the true impact of external influences can be more difficult to determine. The control panel’s properties such as color, material type and whether it is insulated or not must also be considered. Factors such as maximum ambient temperature, effects of local heat sources and solar heat gain must be included when calculating the control panel’s total heat load. The control panel’s properties such as color, material type and whether it is insulated or not must also be considered.

The combination of these factors, plus the heat dissipation and heat load values all play an important part in determining the associated cooling capacity requirements.

Heat Dissipation and the Enclosure Temperature Management Calculator

Installing the appropriate control panel temperature control solution is important in order to properly protect the valuable electrical equipment housed inside. To help ensure that you select the right cooling solution for your control panel, use the Enclosure Temperature Management (ETM) Calculator.

The ETM calculator will help determine whether the control panel cooling needs will require an air conditioner, an air to air heat exchanger or a filtered fan package. Additionally, results will show which size and type of air conditioner will provide the required cooling capacity offering the most energy and cost efficient operation.

Don’t Ignore Control Panel Temperature Control

Although the heat dissipation calculation of a control panel is a simple one, the true impact of external influences can be more difficult to determine.

Many electrical control equipment failures are caused by overheating due to improper control panel cooling, but could be avoided with proper temperature control planning. An excellent place to start is to download the free Thermal Management Guide: Meeting Control Panel Space Requirements and Avoid Overheating e-book to learn more about how to incorporate enclosure cooling into your design and keep equipment operating safely in a smaller control panel.

For additional help the experts at Thermal Edge are available to help you properly chose the correct control panel cooling system for your application.


The Consequences of Neglecting Electrical Enclosure Temperature Control


The Consequences of Neglecting Electrical Enclosure Temperature ControlElectrical equipment manufacturers generally recommend enclosure temperatures be kept below 95ºF (35ºC). Active cooling maintains the electrical components at constant operating temperature, providing a longer and more reliable life span. A crucial first step in determining whether a temperature controlled electrical enclosure is necessary for your industrial application is calculating the heat load.

Besides thermal, other environmental requirements such as moisture and dust must also be considered.

The cost of installing a reliable enclosure cooling system can be far less than the cost of future equipment failure. For this reason it’s best to plan electrical enclosure temperature control during the initial design phase and prior to installation. Continue reading

5 Keys to Protecting an Industrial Control Panel Enclosure


5 Keys to Protecting an Industrial Control Panel Enclosure

When assessing what kind of protection is needed for an industrial control panel enclosure, there are five key factors to consider. These are ambient temperature, humidity, pollution, weather and dust. Once the effects of these factors are adequately assessed, it’s a relatively simple task to evaluate the type of enclosure that’s required and decide how to manage the internal temperature. Here’s how these five key aspects affect enclosure cooling.

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Understanding Ambient Temperatures for Electrical Enclosures


Ambient_Temperatures_for_Electrical_Enclosures“Ambient temperature” is a term you will hear often when researching electrical enclosure cooling systems. But what exactly does it mean? In simple terms, it’s the temperature of the air surrounding an electrical enclosure. As a concept it’s relatively simple, but determining the ambient temperature is not always as easy as it first appears.

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How to Prevent Thermal Damage with Industrial Control Panels


How to Prevent Thermal Damage with Industrial Control Panels

Control panels protect equipment from mechanical damage, as well as inclement weather, corrosive chemicals, falling particulates, and spraying liquids. However, this protection is achieved at a cost: increased exposure to heat. Thermal damage to electrical equipment can result from a number of heat sources, including hot environments and nearby industrial ovens and furnaces. High levels of heat may also be caused by enclosing the heat generating equipment in an industrial control panel along with other heat-generating components.

Excess heat can cause electrical components, such as VFDs, contactors, and power supplies, to lose efficiency—for every degree increase above the manufacturer’s specified operating temperature, efficiency can be derated by two percent. As efficiency goes down, the amount of heat generated increases, compounding the effect. Continue reading

7 Tips for Temperature Control of Electrical Enclosures


7_Tips_for_Temperature_Control_of_Electrical_EnclosuresThe temperature of equipment in electrical enclosures must be controlled to avoid the risk of equipment failure due to overheating. In most cases, some form of enclosure temperature control is needed.

These seven tips can help you assess your temperature control systems. Although enclosures dissipate heat, the total heat load in many instances exceeds the rate at which this heat can be dissipated, and the internal enclosure temperature may exceed the maximum temperature limits of the equipment. Continue reading

What You Need to Know About Cooling Control Panel Enclosures


What_You_Need_to_Know_About_Cooling_Control_Panel_Enclosures.jpgControl panels are designed to house and protect electrical components for powering and controlling industrial, HVAC, and other equipment. Industrial control panels may include PLCs, VFDs, contactors, fuses, switches, transformers, timers, and other components, each of which operates within an optimal temperature range. Continue reading

How to Ensure Accurate Temperature Control in an Enclosure



Although electrical control equipment generally operates over a relatively wide temperature range, sometimes it’s best if the operating temperature is tightly controlled. The reason for this is that the wide temperature cycling that can occur in an enclosure may be detrimental to the equipment, and the output of carefully calibrated control devices could vary if the temperature variations are excessive.

If required, it is possible to achieve very accurate temperature control in an enclosure. This can be achieved as follows. Continue reading

The Risks of High Internal Electrical Enclosure Heat Load


electrical-enclosures-high-internal-heatIn most cases, the primary source of heat in an electrical enclosure is the components inside. Sometimes solar heat gain or an extremely high ambient temperature can also contribute to high internal enclosure temperatures, but most of the time it’s the components themselves that are their own worst enemies.

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2 Solutions for Climate-Uncontrolled Environments for Electrical Enclosures

shutterstock_80404600When an electrical enclosure is located outdoors or in an environment that is not climate controlled, the components inside must be protected from over-heating. Electrical components generate heat when they operate, and the external temperature around the electrical enclosure can also add additional warmth and humidity to the equation. These two factors contribute to the heat load of the enclosure, which helps determine the type and size of cooling system to use.

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