Ricoh K-C3 Service Manual page 266

B245/B276/B277/B268/B269 Service Manual 18-Jan-06
feature can fully protect the hardware. The second feature works as the fail-safe feature for
the first one. The third feature works as the fail-safe feature for the second one.
First Feature:
If the fusing temperature reaches 230C (or higher) and stays so for one second, the controller
turns the fusing lamp off. In a case like this, SC543 or SC553 shows.
Second Feature:
If the fusing feature reaches 250C, the controller cuts off the 24V line. (The fusing lamps are
on the 24V line.)
Third Feature:
Two thermostats are attached on each line of the two fusing lamps. (four thermostats in total).
One of the two thermostats cuts the power supply to the fusing lamp at 179C, and the other
cuts the power supply at 180C. (Note that the thermostat temperature is somewhat lower
than the fusing temperature.)
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