IMAGE FUSING AND PAPER EXIT  20 June 2005 
6-102 
 
6.15.11 COOLING AND OVERHEAT PROTECTION 
 
 
The fusing unit operates at temperatures lower than the previous model in order to 
accommodate the new toner which has a lower melting temperature. In order to 
further ensure cooler running temperatures for the fusing unit, two cooling fans 
have been added.  
The side cooling fan [A] and corner cooling fan [B] switch on when the temperature 
of the fusing unit exceeds 150 °C and switch off when the main motor switches off. 
If the hot roller temperature exceeds  230 °C for 5 seconds or more, the CPU cuts 
off the power to the fusing lamp, and SC543 (Fusing Overheat Error) will be 
displayed.  
Even if the thermistor overheat protection fails, there is a thermostat in series with 
the common ground line of the fusing lamp. If the temperature of the thermostat 
reaches 210 °C, the thermostat opens, removing power from the fusing lamp. At 
the same time, the copier stops operating. At this time, SC542 (Fusing 
Temperature Warm-up Error) will be displayed. 
B195D986.WMF
[A] 
[B]