Fixed speed compressors, also referred to as on-off compressors, operate at a single, constant speed. They continuously switch on or off to meet your refrigeration unit’s demand requirements. This means they turn on when needed, operate at full speed until they meet demand, and then shut off again.

The difference between fixed speed and variable speed compressors is their operation. Fixed speed compressors use only one speed while variable speed compressors can adjust their speeds to fit the demand requirements. This means that variable speed compressors are more energy efficient than fixed speed compressors. They also recover more quickly from a door opening, meaning they work better in food service applications than fixed speed.

Compressors come in three types:

• Hermetic
• Semi-hermetic
• Open

Hermetic compressors are completely sealed to protect against the external environment with a welded-shut casing. Because they are completely sealed, the compressor cannot be accessed. This means that if the compressor fails, it cannot be serviced. It must be replaced. Hermetic units are common in consumer appliances like home refrigerators, but they may be used in small, refrigerated displays.

Semi-hermetic compressors have the compressor and motor housed in a sealed shell. But, unlike hermetic models, semi-hermetic units can be opened for diagnostics and repairs. Because they can be maintained and serviced, semi-hermetic compressors tend to last longer than hermetic units.

Open compressors keep the motor and compressor separate from one another. The compressor connects to the motor by way of a belt or crankshaft. Their design allows for easy access to all parts in case of repair. However, because open compressors do not have a sealed shell like hermetic and semi-hermetic units, they are more prone to leaks and damage from debris.

Embraco, a portfolio brand of Nidec Global Appliance, has become a global supplier of refrigeration technology for the residential and commercial cold chain. Their innovative products continue to exceed the demands of the market.

Their quality selection of fixed speed compressors includes the following series:

• ES series: These compressors are Embraco’s smallest fixed speed compressors that include high-tech and high efficiency levels.
• EG series: This series of compressors comes with four levels of efficiency: standard, medium, high, and very high. They have low noise and vibration levels. Though ideal for household refrigeration, these compressors are also suitable for some medium-sized commercial applications.
• EM series: One of Embraco’s bestselling compressors, the EM series works well in household refrigeration and small commercial appliances. These compact compressors have low noise and vibration levels.
• F series: This series consists of long-lasting, heavy-duty light commercial type compressors. They work in water coolers, beverage coolers, reach-in and chest freezers, professional kitchens, refrigerated islands, and more.
• NE series: These are used in commercial applications and have two efficiency levels. These units were developed for low and medium temperatures and can go up to 1 HP. They consist of highly efficient, medium sized, and sturdy compressors that work in ice makers, slushy machines, reach-in freezers, and more.
• NT series: These units can cover a wide variety of applications up to 1 1/2 HP. Optimized for ultra-low temperature applications, they can work in beverage coolers, upright cabinets, and other ultra-low temperature refrigerators.
• NJ series: In the large frame category, these reliable compressors work for high cooling demands in ultra-low, low, and medium temperature applications. They also keep low noise and vibration levels. The NJ series works in reach-in freezers, cold rooms, ultra-low temperature refrigerators, and more.