Ricoh G148, Service Manual

Page: 455 / 537

Drum Ventilation and Ozone Filter
Cooling prevents uneven buildup of negative ions which can lead to uneven charge on the drum surface.
The drum cooling fan [A] draws cool air into the machine and sends it over the charge corona unit [B] and
down through the vents in the ends of the drum [C].
The PCU cooling fan [D] cools the drum and charge corona unit from the other end.
The dust filter [E] above the charge corona unit absorbs ozone in the air coming from around the drum.
The exhaust fan [F] vents the hot filtered air from inside the machine.
Fan Operation Timing
Drum cooling fan Turns on and off at the same time the polygon motor
PCU cooling fan
Stays on when the fusing lamp temperature is being controlled (at all times except
in auto off or night mode).
Exhaust fan
Switches on after the power switch is turned on, and remains on. However, to
reduce noise and conserve energy, this fan turns slower when the drum motor is
off.
6. Details
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