Principles Of Operation - Mitsubishi Electric JT-MC106G-W-NA Handbook

8. Principles of operation

Descriptions of circuit operation
( 1 ) Notes for turning the power ON / OFF
1 When the power is turned ON, the power light (LED 1) turns on after 1.5 seconds, and the hand dryer be-
comes ready for operation.
• Before the power light turns on, the hand dryer will not operate even if hands are inserted in the hand dry-
ing area. In the meantime, the microcomputer (IC1) of the main unit performs the initial settings.
2 When the power is turned OFF, the power light turns off and operation stops.
• The circuitry takes about 30 seconds to discharge the voltage retained in it. Wait until the discharging time
elapses before plugging in or out the connectors, replacing the circuit boards, or doing other maintenance.
• Even when any error is occurred, the error display will go off if the power has been turned off. Only when a
microcomputer error is occurred, the error display persists till the voltage retained in the circuitry has been
discharged (till the microcomputer has been reset).
(2) Hand detection and operation
1 A range sensor is used as the hand detection sensor.
2 The sensor does not detect hands in the following occasion:
• When the sensor switch is turned off
3 When the sensor detects hands, the blower motor turns on and the hand dryer starts to operate.
4 Once operation has started, it continues as long as the sensor detects hands.
5 If 1 second elapses without detecting hands by the sensor, the blower motor turns off and operation stops.
The time until the blower motor turns off can be set to 1 or 2 seconds with the switch (SW3-1).
6 The hand dryer continuously operates for up to 40 seconds.
• Once 40 seconds have elapsed, the hand dryer stops operating even if hands are detected.
• Since this is a function to assume the presence of a foreign object, the operation will resume if hands are
pulled out and reinserted.
(3) Control of the blower motor
1 The motor does not start in the following occasions:
• When a temperature detected by the thermostat on the control circuit board (JT-33M) is 65°C or higher, or
when a temperature detected by the thermostat on the power circuit board (JT-33P) is 65°C or higher
2 The air speed decreases in the following occasion:
• When a temperature detected by the thermostat on the control circuit board (JT-33M) is 41°C or higher
(4) Control of the heater
1 To regulate inrush current at startup, the heater turns on 0.5 seconds later than the blower motor.
2 The heater does not turn on in the following occasions:
• When the heater switch is turned OFF
• When a temperature detected by the thermostat on the control circuit board (JT-33M) is 31°C or higher, or
when a temperature detected by the thermostat on the power circuit board (JT-33P) is 55°C or higher
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