Operating in conditions with extremely cold temperatures requires equipment capable of withstanding it. Learn more about finding the right variable frequency drive for -40 ℃ weather and the impact it can have on your operations.
Tips for Finding A Low-Temperature Variable Frequency Drive
If you need to source a low-temperature variable frequency drive such as -40℃, there are very few options on the market as most off-the-shelf drives only rate to -10℃, with a few rated at -20℃. Minus 40℃ is the low temperature extreme designated by most military electronic standards to achieve “mil-spec” or ruggedized drive rating. Coincidentally, -40℃ and -40℉ are the same temperature and will sometimes be represented as just “-40” without the C or F designation.
Low temperature-rated single and 3-phase drives rated for -40℃ are required for Military and outdoor commercial applications such as rooftop A/C, heaters, generators, oil pumps, etc. The drive must be prepared for extreme low and high temperatures wherever they operate.
The drive also may need to be World Rated because the final installed location may not be known. Militaries must be prepared to operate anywhere in the world. Also, international business and consumer products work and are shipped worldwide.
Where Is -40℃ Temperature Recorded?
While -40℃ is an extremely low temperature, it is not uncommon and indeed not the lowest recorded for specific areas. The lowest recorded temperature on Earth was -89.2℃, recorded in Antarctica on 21 July 1983. In the US, cities including Fargo, Wilston, and Grand Forks, ND, regularly reach -40℃, as does Duluth and St. Cloud, MN. Many states have recorded temperatures far below -40℃. While some of these are decades old and historic, some are as recent as 2019 at Mt. Carol, IL.
How Does Extreme Cold Impact Electronic Performance?
We all know the impact of extreme cold on solids and liquids. Solids become more brittle, making them susceptible to breakage. Liquids freeze and expand and cause their containers to swell and burst. But what about electronics? Some components work better when they are cold, such as microprocessors, which generate heat that must be dissipated. The colder they are, the faster they can process. However, circuit boards, connectors, and switches can become brittle and break with vibration or shock. Batteries and capacitors can fail mechanically due to freezing of the electrolyte. One of the biggest issues with low temperatures is that capacitors lose much of their capacitance value when cold, making them discharge more rapidly. Other consequences include:
Cold temperatures can cause batteries to lose their charge more quickly. The chemical reactions inside batteries slow down in the cold, reducing their capacity. In extreme cold, batteries may even temporarily fail to provide power, which can be problematic for portable devices.
Poor Response Time
Cold temperatures can slow down the response times of electronic components, such as microprocessors and sensors. This can result in slower operation and reduced overall device performance. For example, touchscreen devices may respond less accurately, and applications may run more slowly.
Increased Thermal Stress
Rapid temperature changes, especially from extreme cold to warm, can cause thermal stress in electronic components. This stress can lead to cracks in solder joints or semiconductor materials, potentially damaging the device’s functionality.
Increased Exposure to Moisture
When electronic devices are exposed to cold temperatures and then brought into a warmer environment, moisture can condense inside the device. This can lead to short circuits, corrosion, and other damage to internal components. Proper insulation and sealing are essential to prevent moisture-related issues.
Therefore, modifications must be made to variable frequency drives for them to withstand low temperatures.
Our Variable Frequency Drive Consulting Solutions
Invention House’s expert knowledge of low-temperature variable frequency drives allows us to provide enhanced support to keep your equipment operational. Learn more about our consulting services.
How Can Motor Drives Achieve a -40℃ Rating?
There are five main things to consider when designing a drive for -40℃:
Mechanical Stress Caused by the Wide Temperature Difference
Components can become brittle at low temperatures, and some coatings and materials may swell at extreme temps. The design must account for these mechanical changes to make sure components do not break during vibration or get lifted from the board, causing an open or short condition.
Startup of the Oscillators of the CPU’s
To ensure startup and function, the oscillators need to be rated and designed to start at -40℃.
Timing of Gate Drives.
The gate circuit of a drive has very critical microsecond timing. Low temperature changes the delays in a gate drive. The change in timing can cause catastrophic failure if not accounted for.
At -40℃, all the components are near their limit of operation. It is recommended that drives be 100% tested for operation at -40℃.
Why Is Invention House the Best Source for -40℃ Variable Frequency Drives?
Invention House designs and manufactures a line of custom variable frequency drives, which are all rated at and 100% tested at -40℃. In addition to our own line of mil-spec and ruggedized drives, Invention House provides expert motor control consulting services. Our line includes single and 3-phase drives, which have all been tested at -40℃ and meet other mil-spec ratings. Invention House is a military-approved small business vendor with Cage Code 58XJ1.
- Input/output frequencies up to 400Hz
- Temperature range from -40℃ to 55℃
- Continuous vibration up to 2grms
- Shock (drop) up to 40g
- Humidity up to 95% non-condensing
- Stall prevention
- Auto restart
- Operation at altitude up to 14,000 ft.
Invention House is ready to take on your extreme temperature motor drive challenge. Request a quote on our -40℃ motor drives today or contact Invention House for a free consultation to learn more about our -40℃ motor drive and mil-spec drive capabilies.
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