When purchasing electronically commutated (EC) motors, you're probably concerned about speed, noise and potential energy savings. If the motor will be powering a commercial refrigeration unit, you should definitely be thinking about IP ratings as well. Below we'll dive into the details of IP ratings and the implications these seemingly arbitrary numbers have on your motor's protection and long-term performance.
EC motors used in commercial refrigeration systems require protection against several factors, including dust and liquid (in various forms). Below are just a handful of examples of common threats to motors in such applications:
While certain measures can be taken to protect a motor against the elements it's subjected to in a commercial refrigeration application, the best way to ensure protection and consistent performance is to opt for an EC motor with a higher IP rating so you can rest assured many of the threats above will become non-issues, as the motor essentially protects itself.
The ingress protection (IP) rating code is an international standard (IEC 60529) used to define levels of sealing effectiveness of electrical enclosures against intrusion from foreign bodies (tools, dirt, etc) and moisture.
IP ratings are represented by two digits. The first number indicates the object's protection rating against solid foreign bodies (like dust, tools and body parts). The second number represents the degree of protection against moisture, from drops of water to total submersion. The higher the number, the better protected the equipment will be.
The chart below, courtesy of superbrightleds.com, outlines the specifics of each numerical rating. Click the image to view larger.
Now we'll take a look at a real-life scenario: Let's say you have two refrigerated display cases in your store. One is outfitted with an IP54 motor, while the other is powered by an IP67 motor. These ratings have major implications for each motor's level of protection, durability and longevity.
Although IP54-rated motors are very common in these types of applications, they allow dust entry, are only protected against splashing water (not immersion) and allow limited liquid entry. Such conditions put these motors under constant stress and ultimately shortens their lifespans.
Your IP67-rated motor, on the other hand, is dust-tight and can tolerate short periods of immersion with no liquid entry. Sounds a lot healthier for your motor than the scenario above, doesn't it? This means your motor won't be threatened by washdown – so you end up with a squeaky clean refrigerated case and no motor damage. Win-win!
All of this is to say that the benefits will certainly outweigh the costs if you choose an IP67 motor over something like an IP54 motor, and your IP67 motor will be around a bit longer. How can I be so sure? Because water ingress is the #1 source of motor failure in commercial refrigeration systems. So your best bet is to choose a motor that is well protected against liquid entry, period.