GF83.70-P-3047A | Alternating full load and partial load, function | 3.4.98 |
MODEL 210 from 1.3.97 to 31.5.98 with ENGINE 602.982
with heater booster
P83.70-0408-09
1 Burner housing
2 Heat exchanger
A1 Instrument cluster
M13 Coolant circulation pump
Y23 Fuel metering pump
A6m2 Combustion air blower
A6n1 Heater booster control module
G2 Generator
Function sequence
The temperatures for switching thresholds have been changed as of 1 February 98. The temperature values indicated in parentheses are valid up to 31 January 98.
1 Coolant temperature < 72 °C (< 61 °C)
Outdoor air temperature 5 °C
The vehicle engine runs and the instrument cluster (A1) is actuated by the generator (G2) via circuit 61 (charge indicator). The heater booster control module (A6n1) receives a positive signal for operation of the heater booster from the instrument cluster (A1).
2 The heater operates at full load. The combustion air blower (A6m2) and fuel metering pump (Y23) operate at maximum speed and output. The coolant circulation pump (M13) pumps coolant through the heat exchanger (2). The temperature of the coolant increases.
3 The coolant temperature reaches 72 °C (61 °C), the maximum heater output can be reduced, because the heat requirement has decreased.
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4 The control module (A6n1) switches the combustion air blower and fuel metering pump to partial load by reducing the output infinitely within 55 s.
5 The coolant temperature drops and the heat requirement increases again.
6 The coolant temperature reaches 64 °C (56 °C), the heat requirement makes it necessary to increase the heater output.
7 The control module switches the combustion air blower and fuel metering pump to full load by increasing the output infinitely within 55 s.
8 The coolant temperature increases again.
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This alternation between full load and partial load continues until the coolant temperature has reached 82 °C or the outdoor air temperature increases to above 5 °C. In both cases operation of the heater booster is interrupted and the heater shut-off delay is started.