An introduction to temperature rise inside enclosures
 

An Introduction to Temperature Rise Inside Enclosures

May 30, 2022by yongubox0

An Introduction to Temperature Rise Inside Enclosures

Traditional notions that electro-mechanical equipment can survive relatively high temperatures might influence the argument on enclosure cooling. This belief does not consider the detrimental effect high temperatures have on contemporary electrical and electronic devices. The truth is that most industrial electrical equipment is not built to withstand the high temperatures that can be found within enclosures during hot climates or in scorching corporate sectors. Premature failure is typically the result of this.

 

Thermal Considerations

Due to the thermal dissipation of instrumentation mounted inside enclosures, the temperature inside the enclosure rises above the ambient temperature found outside the enclosure. This is because the temperature inside the enclosure is affected by the equipment mounted inside the enclosure.

The term “enclosure temperature rise” refers to the increase in temperature that occurs when the air inside an enclosure that is neither vented nor cooled is compared to the air found outside the enclosure. The temperature increase inside the enclosure is not reliant on the temperature outside; instead, it is determined by the heat produced inside the enclosure and the measures that are done to disperse that heat.

Designers can now fit more equipment into a smaller area because of the ever-shrinking size of electrical and electronic components. Heat dissipation is critical because of the elevated interior temperatures caused by the high density of equipment. In addition to shortening the lifespan of electrical and electronic components, excessive heat also degrades the insulation around those components.

 

Influence of Temperature Rise on Equipment Expected Life

“Expected Lifetime” describes the period between installing a production unit and equipment failure. This estimate is dependent on several environmental factors, including temperature.

An operational temperature range provided by the unit is assumed in the calculations for the estimated lifetime. The estimated lifespan of the equipment is unaffected by operating it below a specific temperature. High temperatures shorten the equipment’s estimated lifespan because of an increase in the failure rate. The Arrhenius effect equation states that the failure rate doubles for every ten degrees Celsius rise in operational temperature.

High-temperature electrical equipment may be manufactured; however, the recommended operating temperature ranges between 40 to 50  ºC.

For instance, depending on the temperature, a capacitor can last 32 years at 45 degrees Celsius, 16 years at 55 degrees Celsius, and just four years at 80 degrees Celsius. Keeping the temperature in electrical equipment enclosures as low as possible is recommended.

Another fact to consider is that Integrated circuit leakage currents rise with temperature, resulting in unstable operation over a particular threshold when digital electronic control circuits get too hot. PLCs, computers, and other equipment containing microprocessors may be affected. In most cases, no permanent harm is done, although industrial control systems suffer from these accidents.

Temperature Rise

 

Design and Installation Issues for Heat Dissipation

The following are some heat-related concerns during design reviews and troubleshooting:

  • Enclosure designs that do not enable proper heat dissipation and air movement, resulting in highly high interior temperatures, have been observed.
  • Designs that don’t allow for enough ventilation in some enclosure portions might produce hot spots.
  • These enclosure
  • s may experience greater ambient temperatures if exposed to direct sunshine or neighboring heat-producing equipment.
  • Interconnected wiring and cabling crammed into a small space, making it difficult for air to circulate freely.
  • Items with opposite-side cooling slots and neighboring products installed too close may not get appropriate cooling air.
  • The power supply that generates significant interior temperatures should not be installed in the enclosure.

 

Enclosure Cooling & Improved Heat Dissipation Options

Many cooling techniques are available to keep electronic equipment from overheating depending on the enclosure’s size and heat load. The most straightforward method is to utilize cooling fans to promote air circulation and lower the enclosure’s temperature. This approach relies on the temperature of the surrounding air, and the temperature of the enclosure will be higher. However, when used in high-temperature or electrically-loaded enclosures, it’s not advised.

Enclosure air conditioners, air-to-air heat exchangers, or air-to-water heat exchangers are the most effective ways to regulate the temperature of electronic equipment enclosed in a sealed enclosure.
Some methods to consider for improved heat dissipation are:

Placement of Equipment

Placement and positioning of equipment make use of natural cooling vents. Specified distances from equipment must be taken into consideration while designing enclosures. The wire must at the very least comply with local, regional, and national norms like the NEC to guarantee that it can safely transmit load without overheating.

Introduction of Vents & Auxilary Designs

  • Cool air is drawn in from the sides and the top while warm air is expelled.
  • Airflow can be improved by using instrument air and vortex coolers, which enable positive pressure within the enclosure and modest volumes of air.
  • For best ventilation and heat dissipation, heat sinks or cooling fans drive air through the enclosure sheet metal.
  • Make sure conduit gaps aren’t allowing warm, damp air from other locations to enter the enclosure.

Temperature Rise

Circuit Design Considerations

Circuits should be designed so that no power is dissipated inside the enclosure. Parallel and series wiring are two examples of circuit configurations. Series wiring is more efficient in dissipating energy within the enclosure, whereas parallel wiring is more efficient at dissipating power in the field.

High Heat Dissipation Device Placement

  • Place high-heat loads near the top of the enclosure to prevent heat from escaping through the top of the enclosure and into adjacent devices.
  • Place hot components close to enclosure edges for maximum heat transfer through the enclosure’s sides.
  • Place hot loads in a way that encourages airflow circulation.

Installation on Shaded Area

Solar energy absorption can boost the temperature within field enclosures when exposed to direct sunshine. Sun blinds or shields can help keep the enclosure and electrical components cooler depending on the surrounding conditions.
By effectively regulating the heat generated by the enclosure, these techniques can increase system availability and the estimated lifespan of the unit.

 

Maintenance Considerations

It is critical to do routine maintenance. Cleaning or replacing air filters is necessary from time to time. Poor air conditioning, higher temperatures, and a lower projected lifespan are consequences of clogged air filters.

To guarantee optimal temperature levels within enclosures and identify “hot spots,” frequent audits are highly advised. The inner temperature of a cabinet or enclosure may be measured by taking readings at the top, center, and bottom. On the other hand, thermal pictures are the recommended approach for measuring temperature. Hot spot readings might point to a more severe problem to be addressed. The audit should verify, among other things, that the direction, speed, and airflow of the fans are accurate.

 

Calculating Temperature Rise

The following processes and calculations can be used to estimate the rise in temperature within the enclosure:

  • The interior surface area must be determined at first.
  • To calculate the amount of power needed to run the system, divide your projected heat load by the area of the interior.
  • The temperature rise may be estimated by determining where the Internal Heat Load value meets the line and reading the approximate temperature rise on the graph. Safety issues should be taken into consideration while using these figures.

YONGUBOX ELECTRIC BOX

YONGU presents electrical enclosures in three different series, including H Series, J Series & K Series to deal with all the problems stated in the article above with multiple other benificial aspects.

H Series – YONGUBOX H37 204*48*L Electronic Aluminum Enclosures

It is available in  61 different models with built-in split-type extrusion structures, including 1pc top housing, 1pc bottom housing, 1pc front panel, and rear panel. Good heat dissipation, easy to be assembled. L shape brackets for panels can be customized to wall mount

Its specific features include

  • Electronic Aluminum Enclosures
  • Rugged and robust for heavy-duty use
  • Durable, which can be used for a long time
  • Good quality aluminium material, al6063, and al5052
  • Can be used for din rail
  • Completely customizable in every aspect of dimension, hole drilling, screws, surface treatment, and printing.

 

J Series – YONGUBOX J12 66.2*27.5*L Aluminum Box for Electronic

It is available in  44 different models of built-in one-piece structure extruded, including 1pc main enclosure, 1pc front panel, and 1pc rear panels—good heat dissipation, easy to be assembled.
Its specific features include:

  • Aluminum Box for Electronic
  • Rugged and robust for heavy-duty use
  • Durable, which can be used for a long time
  • Good quality aluminum material, al6063, and al5052
  • Can be used for din rail
  • Customizable panel thickness from5mm/2mm/3mm/5mm/8mm, etc., hole drilling, screws, surface treatment, and printing.

 

K Series – YONGUBOX K01A 70*35*L Plastic Junction Box

It is available in 28 Models waterproof series, including full plastic protected plastic covers, half protected plastic covers with aluminum end panels, half protected plastic end covers, and wall-mounted flange. It can use the sticker instead of the printing.

Its specific features include

  • Plastic Junction Box
  • Rugged and robust for heavy-duty use
  • Dustproof, which can protect your PCB from hitting
  • Extruded aluminum housing and ABS protected covers
  • Conductivity can be achieved by utilization of the contact between the unfinished inner surfaces
  • Completely customizable in every aspect of dimension, hole drilling, screws, surface treatment, and printing

 

Benefits

An electrical control box from YONGU combines aluminum and plastic to provide the best possible protection for your wiring. The rated voltage for the YONGU aluminum electrical enclosures is up to 1,000 volts. Because of the potential for higher short circuit currents at the input makes installing a current-limiting protection device with a high cut-off current necessary.

Weatherproof electrical control boxes are designed to keep moisture out of electrical and electronic circuits by using an innovative design. Small electrical control boxes and standard electrical pull box sizes are available in YONGU aluminum electrical enclosures, along with the necessary customization options for installation.

If the correct material and models are selected, they can deal with temperature, moisture, and humidity issues.

Standard DIN rails, mounting plates, front panels, and dividers can all be attached without any tools, thanks to the system’s tool-less mounting options. Preassembly outside the enclosure is made simple by connecting the accessories to mounting brackets of varying heights and sliding them into the enclosure. The assembled modules can be inserted and removed without using any tools.

If you’re looking for a way to keep your electronics safe, YONGU’s electrical control box is a great option. They can be used in various industries and applications, including solar power, wind turbines, and building HVAC controls.

 

For further information and customized product of your requirements, follow our Facebook for more details: YONGUBOX.

You can also contact us at +86 13326782625 or write us at salesglobal@yonggu-enclosure.com.

 

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