A control cabinet always develops heat. That happens from components such as power supplies, PLCs, variable speed drives, relays, contactors, network components and cabling. In a well-designed cabinet, that heat is dissipated in a controlled manner. But when heat generation exceeds heat dissipation, interior temperatures rise. <\/p>\n
This may seem like a minor problem, but in industrial plants, an overheated control cabinet can directly affect the reliability of a machine, production line or automation process. Components age faster, failures increase and, in the worst case, a plant falls down unplanned. <\/p>\n
Therefore, the question is not only: should this switchboard be cooled?<\/strong><\/b> If this is not the case, then additional control cabinet cooling<\/a> is required. In this article, we explain when cooling is needed, when ventilation may be sufficient and when active cooling, such as a cooling unit or air conditioner, is the right choice. <\/p>\n The temperature in a control cabinet directly affects the service life and reliability of electrical components. Many components are designed for a certain temperature range. If the inside temperature becomes too high for a long period of time, the likelihood of malfunctions increases. <\/p>\n In panel construction, therefore, we look not only at the electrical operation of a switchboard, but also at its thermal structure. Where are the heat-producing components located? Is there enough room for air circulation? Can hot air be exhausted? And in what environment will the cabinet be placed? <\/p>\n Excessive cabinet temperature can lead to, among other things:<\/strong><\/p>\n Important in this regard: the temperature in the room is not the same as the temperature in the cabinet. A production space of 30 \u00b0C may seem acceptable, while the temperature in a closed automation cabinet rises much higher due to heat generation. <\/p>\n Therefore, cooling should already be included during engineering. Not as a separate addition afterwards, but as part of the overall cabinet design. <\/p>\n Not every control cabinet needs a fan or cooling unit. In some situations, passive heat dissipation is sufficient. The cabinet then dissipates heat through the cabinet surface, the material of the enclosure and natural air movement around the cabinet. <\/p>\n Passive heat dissipation may be sufficient when:<\/strong><\/p>\n The material and arrangement of the enclosure play a role here. An enclosure made of painted sheet steel or stainless steel dissipates heat differently than a compact plastic enclosure. It also matters whether a cabinet stands freely, hangs against a wall or is placed in a row with other cabinets. The less free surface area available, the more limited the natural heat dissipation. <\/p>\n Passive heat removal is simple, low-maintenance and energy efficient. But its capacity is limited. Once the dissipated power in the cabinet increases, the ambient temperature rises, or the cabinet is built more compactly, passive heat dissipation is often no longer enough. <\/p>\n Therefore, it is wise not to choose by feel, but to calculate the control cabinet cooling<\/a> based on heat load, cabinet arrangement and ambient temperature.<\/p>\n Cooling is often discussed in practice only when there are already malfunctions. Nevertheless, there are clear signs you can recognize that the heat management of a switchgear cabinet needs attention. <\/p>\n A control cabinet can still remain within the desired temperature at startup, but become too hot during production. This happens especially when components run under load for long periods of time. Consider variable speed drives, power supplies, motor controls and industrial electronics that are continuously active. <\/p>\n If the temperature rises especially during peak load, hot days or prolonged operation, it is a clear sign that heat dissipation is inadequate.<\/p>\n Some failures seem random, but in reality have a thermal cause. For example, a power supply, inverter or controller may fail only when the cabinet temperature becomes too high. Once the system cools down, the problem seems to disappear temporarily. <\/p>\n This makes heat problems difficult to identify. This is precisely why it is important to look not only at the error message, but also at the circumstances in which the malfunction occurs. <\/p>\n Modern automation cabinets are becoming more compact. This is efficient, but it also increases the likelihood of local hotspots. In particular, inverters, power supplies, softstarters, power modules and industrial network components can give off a lot of heat. <\/p>\n If these components are placed close together without adequate air circulation, a cabinet can become overheated locally. Even when the average cabinet temperature still seems acceptable. <\/p>\n The environment strongly determines which cooling solution is appropriate. A cabinet in a clean technical room requires a different approach than a cabinet in a dusty production environment, outdoor setup, refrigeration plant, maritime environment or room with high humidity. <\/p>\n Dust and dirt can clog filters. Moisture can cause condensation. Salty air can accelerate corrosion. And with outdoor cabinets, sun exposure also plays a role. <\/p>\n With a high IP rating, you cannot simply add openings, grilles or fans. The IP integrity of the cabinet must be maintained. Especially with IP65 or similar degrees of protection, cooling requires extra attention. <\/p>\n A fan can technically move enough air, but at the same time reduce protection from dust or water. In such situations, a closed cooling solution often makes more sense than open ventilation. <\/p>\n Ventilation and cooling are often used interchangeably, but technically they are different solutions.<\/p>\n Ventilation moves air.<\/strong><\/b> A fan or filter fan exhausts warm air and brings cooler outside air into the cabinet. This works well only when the outside air is cooler than the desired cabinet temperature and clean enough to allow into the cabinet. <\/p>\n Active cooling lowers the temperature.<\/strong><\/b> A cooling unit or air conditioner actively dissipates heat with refrigeration technology, often with a compressor. This allows the temperature inside the cabinet to be kept lower than is possible with ventilation. <\/p>\n There are also intermediate solutions, such as heat exchangers. These dissipate heat without cabinet air and outside air mixing directly. This is interesting when dust, moisture or dirt must remain outside the cabinet. However, a heat exchanger is not sufficient in every situation, especially when the ambient temperature is high. <\/p>\n Broadly speaking:<\/p>\n Passive heat dissipation<\/strong><\/b> is suitable when heat generation is low and the environment is favorable.<\/p>\n Ventilation<\/strong><\/b> is appropriate with limited heat generation and clean, cooler outside air.<\/p>\n A heat exchanger<\/strong><\/b> is suitable when cabinet air and outside air must remain separated, but there is still sufficient temperature difference.<\/p>\n Active cooling<\/strong><\/b> is needed when ventilation or passive heat dissipation is insufficient.<\/p>\n Are you hesitating between a fan, heat exchanger or air conditioner? We compare these solutions in more detail on the air conditioner vs ventilation switchboard<\/a> page. <\/p>\n Active cooling is necessary when heat can no longer be dissipated sufficiently through the cabinet surface or with ventilation. This is especially important in cases of high heat generation, high ambient temperatures or closed control cabinets. <\/p>\n Active cooling is often required when:<\/strong><\/p>\n A simple example: if the space around the cabinet becomes 35\u00b0C and the desired indoor temperature is at most 30\u00b0C, ventilation cannot solve this. This is because a fan uses the same warm ambient air. In that case, active cooling is needed to actually lower the cabinet temperature. <\/p>\n Active cooling can also be necessary for closed control and switchgear cabinets with a lot of electronics. Especially when the cabinet is part of a machine, production line or industrial installation where downtime has an immediate impact. <\/p>\n For applications requiring an air conditioner or cooling unit in or on the cabinet, a cooling unit panel<\/a> can be an appropriate solution.<\/p>\n The right cooling solution depends not only on the components in the cabinet. The environment in which the control cabinet is placed also determines what is technically wise. <\/p>\n
\nThe better question is: Can this control cabinet safely dissipate heat under all operating conditions?<\/strong><\/b><\/p>\nWhy temperature in a control cabinet is important<\/h2>\n
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When is passive heat dissipation sufficient?<\/h2>\n
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Signs that your control cabinet needs cooling<\/h2>\n
Cabinet temperature rises during production<\/h3>\n
Faults occur mainly when there is heat or high load<\/h3>\n
There are many heat-producing components in the cabinet<\/h3>\n
The cabinet is in a hot, dusty or humid environment<\/h3>\n
The IP class limits ventilation<\/h3>\n
Ventilation or active cooling: what’s the difference?<\/h2>\n
When is active cooling necessary?<\/h2>\n
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Environmental factors influencing choice<\/h2>\n