"Controlled heater operation", function

W83.70-0109-06

1 Heater
2 Hot air intake
3 Combustion and hot air blower
4 Control circuit board
5 Flame monitor
6 Glow pin
7 Burner insert
8 Temperature limiter
9 Combustion tube
10 Heat exchanger
11 Fuel metering pump
12 Timer
13 Rotary potentiometer

HE Hot air inlet
HA Hot air outlet
V Combustion air
A Exhaust

Function sequence "controlled heating"

Controlled operation

 The heater (1) is switched on with the timer (12).

 The heater has completed the start-up phase and is now in the controlled operation phase. It continues at maximum output until the air sucked in has reached the set cab temperature. Then the heating capacity is reduced. The control circuit board (4) decreases the speed of the combustion and hot air blower (3) to 60 % of the maximum speed and proportionally decreases the cycling frequency for the fuel metering pump (11) until the set cab temperature is exceeded.

 If the temperature set on the timer is exceeded and the minimum heating capacity has been reached for more than
5 seconds, the control circuit board switches off the fuel metering pump discontinuing combustion.

 The combustion and hot air blower continues to run for
155 seconds at 60 % of the maximum speed to cool down and purge the heater (cooling phase with shut-off delay).

Controlled shut-off phase

 The heater has completed the cooling phase with delay shut-off and is now in the controlled shut-off phase.

 The combustion and hot air blower continues to run at minimum speed blowing air out of the cab across the temperature sensor on the control circuit board.

 When the temperature drops below the setting on the timer the heater is started up without the break-loose phase. The heater starts running again.