Fusing Temperature Control; Temperature Control - Gestetner B003 Service Manual

6.15.8 FUSING TEMPERATURE CONTROL

The fusing unit for this machine is equipped
with two fusing lamps: the first fusing lamp
(center: 650W) [A] heats the center of the
fusing roller, and the second fusing lamp
(ends: 550W) [B] heats both ends of the
fusing roller. This arrangement ensures
even heat on all surfaces of the roller.
In order to control the temperature of the
roller, two high response thermistors are
attached to the unit, one near the center [C]
and one at the end [D] of the fusing roller.

Temperature Control

Model B003 & B006
°C
(35CPM)
200
140
130
100
Center
End
50
Main SW ON Re-load
There are two types of temperature control:
• On/off control (Default)
• Phase control.
Either mode can be selected with SP1-104 (Fusing Temperature Control).
After the machine is powered on, the CPU checks the ac frequency for 500 ms, in
case phase control is selected later for the temperature control, and then switches
on the fusing lamp.
As soon as both the center and end thermistors detect the re-load temperature
(Fusing temperature − (minus) 30
thermistors detect the fusing temperature, the CPU switches the lamps off but
frequently switches on/off again in order to maintain the fusing temperature.
SM
[B]
°C
200
Fusing Temp.
170°C
155
160°C
150
Center
End
100
50
Main SW ON
B004D518.WMF
o
C), the machine can operate. As soon as the
6-79
IMAGE FUSING AND PAPER EXIT
[D]
[C]
[A]
Model B004 & B007
(45 CPM)
Fusing Temp.
Center
End
Re-load
B003/B004/B006/B007
B004D602.WMF
185°C
180°C
Center
End
B004D519.WMF