Labconco Biological Safety Cabinets 34608 Series - Manual (Page 23)

Chapter 4: Performance Features and Safety Precautions
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Motor/Blower
The motor/blower assembly pulls room air into the front of the cabinet, and
re-circulates it internally. During its recirculation, the air is split into two
separate streams. One path leads through the exhaust HEPA filter and out of
the unit. The second path flows through the supply HEPA filter, which then
flows down through the work area, as shown in Figure 4-4. The motor in the
Purifier Logic Series Cabinet is an electronically commutated motor (ECM).
The ECM is a brushless DC motor that includes its own power supply to
convert the incoming alternating current to direct current, as well as its own
microprocessor to control and measure the motor’s operation. The motor is
preprogrammed to deliver a consistent volume of air, even as the HEPA
filters load over time.
Figure 4-4