
Chapter 2
2-24
2.8.2.2 Protective Functions
2.8.2.2.1 Protective Function of Fixing Unit
0019-9538
Host machine carries the following 3 functions to prevent the fixing heater from overheating.
1) Protective function by CPU
CPU of engine controller monitors the thermistor (TH1) temperature consistently.
When TH1 reaches approx 220 deg C, CPU determines that the fixing heater is overheating and stops the fixing heater drive signal (FSRD) output and also turns
OFF relays to shut the power supply to fixing heater.
2) Protection function by fixing heater safety circuit
Fixing heater safety circuit monitors the thermistor (TH1) temperature consistently.
When TH1 reaches approx 235 deg C, it determines that the fixing heater is overheating and the fixing heater safety circuit turns OFF the relay drive circuit to
shut the power supply to the fixing heater.
3) Protection function by temperature fuse (TP1)
When the fixing heater temperature rises abnormally and temperature fuse (TP1) temperature reaches approx 226 deg C, TP1 opens to shut the power supply to
the fixing heater.
2.8.2.2.2 Error detection
0019-9539
CPU of engine controller determines the fixing assembly error and shuts the fixing heater drive signal (FSRD) and also turns OFF relays to shut the power supply
to the fixing heater in the following cases. Also, it notifies the error status to the main controller simultaneously.
1) Startup error detection
When thermistor temperature does not reach 55 deg C within 1.5 sec from heater ON.
2) Abnormal low temperature error
- After heater ON, when the thermistor detects the temperature of 100 deg C or below at printing after the thermistor temperature reaches 50 deg C.
- After heater ON, when the thermistor detects the temperature of 55 deg C or below at sheet interval or in cleaning mode after thermistor temperature reaches
50 deg C.
3) Overheat error
When the thermistor detects the temperature of 220 deg C or over 30 times consecutively.
4) Frequency detection circuit error (200-240V series only)
When it cannot detect the frequency detection signal during operating the fixing assembly even once for approx. 3.0 consecutive sec.
Содержание LBP3250 Series
Страница 1: ...Aug 13 2008 Service Manual LBP3250 Series LBP3250 ...
Страница 9: ...Chapter 1 PRODUCT DESCRIPTION ...
Страница 17: ...Chapter 2 TECHNICAL REFERENCE ...
Страница 45: ...Chapter 3 DISASSEMBLY AND ASSEMBLY ...
Страница 66: ...Chapter 3 3 19 F 3 67 1 1 2 ...
Страница 67: ...Chapter 4 MAINTENANCE AND INSPECTION ...
Страница 71: ...Chapter 5 TROUBLESHOOTING ...
Страница 77: ...Chapter 6 APPENDIX ...
Страница 82: ...Aug 13 2008 PARTS CATALOG LBP3250 ...
Страница 88: ...2 2 FIGURE 100 EXTERNAL COVERS PANELS ETC 1 2 4 6 9 10 7 8 5 11 3 ...
Страница 90: ...2 4 FIGURE 101 INTERNAL COMPONENTS 1 SEE FIGURE 810 2 3 1 ...
Страница 92: ...2 6 FIGURE 102 INTERNAL COMPONENTS 2 2 5 3 1 4 ...
Страница 94: ...2 8 FIGURE 103 INTERNAL COMPONENTS 3 1 2 4 3 ...
Страница 96: ...2 10 FIGURE 810 FIXING PAPER DELIVERY ASS Y 1 2 3 3 ...
Страница 98: ......