3-Stage Vacuum Motors

Three-Stage Motor

• A vacuum with a three-stage motor has three fans to create airflow, producing the vacuum effect via the spinning blades. All three fans increase the sealed vacuum, which is the air pressure drawn through the unit's system. According to central vacuum maker MD Manufacturing Inc., a vacuum with a three-stage motor has more water lifting capacity than a two-stage motor, but moves fewer cubic feet of air per minute.

Water Lift

• Water lift is a measurement term that describes a vacuum's lifting ability even though the vacuum won't actually be used with water. When discussing a vacuum's water lift capabilities, the suction gauges are calibrated into “inches of water lift.” Completely sealed vacuums measure the unit's pulling power by sucking up water in a column. The vacuum's water lift capacity is determined by how many inches of the water is taken up. Three-stage vacuum motors have a higher water lift capacity than two-stage motors. Some vacuums rate their suction by millibars. Multiply the millibar number by 0.4 to determine the vacuum motor's water lift capacity.

CFM

• Another measurement used for determining the power of a vacuum's suction motor is cubic feet of air per minute, or CFM. This is also known as the air flow rating. The CFM rating is obtained by measuring air flow through the vacuum's power unit with the restriction of a 2-inch opening, which provides resistance to air flow. Two-stage vacuum motors have a higher CFM rating than three-stage vacuum motors. However, a vacuum's CFM rating does not include variables that would affect the unit's performance. Some variables are resistance within the vacuum's motor and air turbulence within the unit's hose.

Central Vacuums

• Three-stage vacuum motors are found in central vacuums, which are stationary units installed in buildings as a semi-permanent fixture. Due to their stationary status, central vacuums have more powerful motors than portable vacuums do. Like portable units, though, the main purpose of a central vacuum is to remove dirt and debris from a flooring, walls and upholstery. Tubing runs from the central vacuum's power unit – the vacuum's stationary part – to wall inlets throughout the house. Homeowners attach tube extensions from the wall inlets to suck up dirt. Central vacuums are generally found in a house's garage or basement.