HP LaserJet Pro M402d - Page 33

Table 1-8 Fuser control functions (continued)
Failure detection function Supported feature
Fuser failure detection Yes
Frequency detection circuit failure detection Yes
Fuser pressure release mechanism failure detection No
Fuser type discrepancy detection No
Fuser type identication detection Yes
Fuser presence detection No
Fuser life detection No
Relay failure detection No
Pressure roller cleaning Yes
Fuser heater protection
Fuser heater protection is a feature that detects excessive temperatures in the fuser and interrupts the power
supply to the fuser heater.
The following three protective components prevent the fuser heater from excessive rising temperature:
●
DC controller: When a thermistor or sub-thermistor detects a temperature above a certain threshold,
the DC controller interrupts power to the specic heater.
●
Fuser-heater safety circuit: The fuser heater safety circuit monitors the detected temperature of the
sub thermistors.
●
Thermoswitch: If the temperature in the heaters is abnormally high, and the temperature in the
thermoswitch exceeds a specied value, the contact to the thermoswitch breaks.
ENWW Engine-control system 15