Ricoh AC205, Руководство по обслуживанию

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SYSTEM LAYOUT
B273 6-4 SM
6.2.4 FUSING ASSEMBLY
The fusing unit consists of the following.
•
Fusing lamp
• Hot roller
•
Pressure roller
• Thermistor and thermostat
The fusing unit uses pressure and heat to melt toner into the paper.
Thermostat
The thermostat cuts power to the fusing lamp to avoid machine overheat. Power is
cut when the thermostat temperature reaches 160
°
C.
Thermistor
The thermistor detects the surface temperature of the hot roller. This information
goes to the main processor, which uses this information to regulate the
temperature of the hot roller.
Hot Roller
The fusing lamp heats the surface of the hot roller. Toner is melted into and
remains on the surface of the paper as the paper passes between the hot roller
and pressure roller. The surface of the hot roller is coated with Teflon to ensure
that toner does not remain on the roller surface.
Pressure Roller
The pressure roller is mounted under the hot roller. It is made of a silicon resin, and
the surface of the roller is coated with Teflon. This ensures that toner does not
remain on the roller surface.
Safety Features
The machine has the following countermeasures to prevent overheating:
1. 1st protection device: Hardware is disabled when the machine temperature
reaches 207
°
C.
2. 2nd protection device: Software is disabled when the machine temperature
reaches 220
°
C for 3 seconds.
3. 3rd protection device: The thermostat measures the temperature of the hot
roller, and disables main power to the fusing lamp when the temperature
reaches a pre-determined level.
Safety Devices
1. Fusing power is cut when the front cover is opened.
2. LSU power is cut when the front cover is opened.
3. The temperature of the fusing units cover surface remains at less than 80ºC.
This protects the user. A caution label is attached where the customer can see
it easily when the rear cover is opened.