How to choose

①Total heat generation inside panel

The total heat generated by the devices housed inside the panel.
*For the heat output of each device, please refer to the heat output list by device.

② Heat transfer rate

The rate at which heat penetrates from outside the panel into the panel.
This varies depending on the type of sheet metal and thickness, but for a 2mm thick steel plate it is approximately 5 [W/m2・℃].

③ Maximum ambient temperature

The highest temperature expected in the installation environment.
Check the highest temperature expected in the environment where the control panel will be installed, such as during the height of summer.

④ Desired temperature inside the panel

Desired board temperature (the recommended temperature is 35°C).
If you set the desired temperature inside the cabinet too low, it not only makes condensation more likely to occur, but also extends the cooling time and increases power consumption.

⑤ panel effective surface area

The total surface area of all surfaces of the target control panel that come into contact with the atmosphere. For freestanding panels, this refers to the surface area excluding the bottom surface.
For wall-mounted installations, the calculation excludes surfaces that do not come into contact with the atmosphere, such as the back panel.

1) Calculate the amount of heat entering through solar radiation.

The amount of sunlight varies depending on the installation location, date, time and orientation.

*Sample data of solar radiation on each surface (Tokyo area, July 22nd, clear skies) Unit: W/m²

Therefore, the required amount of solar heat radiation is calculated for each surface and the sum of the calculations is the amount of solar heat radiation required. The solar heat radiation for each surface can be calculated using the following formula.

Terminology

• Heat transfer coefficient (W/m² °C): Ratio of the amount of heat that enters (or dissipates) by heat conduction to the area when there is a temperature difference between the ambient temperature (the temperature at which the enclosure surface rises) and the desired temperature. panel varies depending on the board thickness and material, but is defined as 5 to 6 W/m² °C by the Panel Heat Related Equipment Manufacturers Association.
• "Heat transfer coefficient on the outside of the housing (W/m²・℃)" - It is estimated to be approximately 10W/m²・℃ when there is no wind, and approximately 15W/m²・℃ when the wind speed is 1 to 2 m/s. The higher the wind speed, the greater the heat transfer coefficient.
• "Casing surface temperature rise (equivalent to outside air temperature rise)": This refers to the equivalent temperature rise due to solar radiation.

From the above, we can see that the temperature will vary depending on the area where the panel is installed, the color and condition of the panel surface, the condition of the panel's outer walls (thickness, double structure, installation of sunshades, etc.), and the condition of the wind circulating outside the panel.

As an example, let's calculate using panel with the following conditions.

◎ Height 2000mm, width 1000mm, depth 500mm◎ Door facing south◎ Tokyo area, July 22nd, clear skies, 2pm, no wind◎ Panel thickness 2mm, paint color: light beige, wall surface is single-layer structure

Caution! As the surface of the disc becomes dull over time, the absorption rate changes, so it is necessary to select a product with safety factor in mind.

2) Select the appropriate unit by matching the required cooling capacity listed above to the capacity-performance curve for each control panel cooler.

<<Notes on selection>>

1. Please note that the amount of heat generated by inverters, servo amplifiers, etc. varies greatly depending on how they are used, motor torque, etc.
2. For inverters with a rating output of 50 kW or more, the amount of heat generated varies greatly depending on the manufacturer, so please check with the manufacturer.
3. When selecting a model, please select one that exceeds the required rating capacity and cooling capacity.
4. Please note that capacity calculated using the above formula are only a guideline and are not absolute values.
5. Please note that depending on the sealing of the panel, the position with the heating element, and the convection in the chamber, the expected cooling capacity may not be obtained.
6. Dirty filter and deterioration of the fan motor may lead to a decrease in cooling capacity, so please perform regular maintenance.

1. power supply and transformer equipment

2. Amplifiers

3. Wiring equipment

4. Control equipment

5. Information and communication equipment

6. Others

remarks
(1) When calculating from rating capacity (VA) and rating output (VA), the heat generation amount (W) is obtained by multiplying by the percentage (%).
(2) Actual heat generation varies depending on the equipment, so it is necessary to check the catalogs and technical documents of each manufacturer.
(3) Wiring and other small components can also be sources of heat, so this must be taken into consideration.