7 Functions
Rev. 06/2020
45
7.4
Cooling of the Dosing Valve
If the temperature at the dosing valve is too high, AdBlue
®
is pumped through the dosing unit by
the pump in order to cool the valve and thus ensure functionality. The AdBlue
®
returns via an
internal bypass line from the dosing unit to the tank.
The cooling circuit remains active until the emission controller is disconnected from the power
supply, even if the device has been switched off via the start/stop input.
The temperature values at which the pump is switched on and off for cooling the dosing valve
can be configured in the MICT. Refer to the section
Exhaust Control – SCR – Pump Setup
on
7.5
Protection against Freezing of the Dosing Valve
To protect the dosing valve from too low temperatures, the temperature sensor of the dosing
unit is analyzed. If the temperature falls below the minimum temperature, the heating of the
dosing unit is switched on.
Protection against freezing is ensured until the emission controller is disconnected from the
power supply, even if the device has been switched off via the start/stop input.
The temperature values at which the heating of the dosing valve is switched on and off can be
configured in the MICT. Refer to the section
Exhaust Control – SCR – Dosing Valve
on page 69.
7.6
Manual and Automatic Operation
The VariSCR emission controller can be operated in two modes:
–
Manual operation
–
Automatic operation
Manual and automatic operation can be switched via the
Manual/Auto
switch or via the MICT. In
this case, the MICT overwrites the switch position on the device. Switching via the
Manual/Auto
switch can be disabled by a setting in the MICT. If the status LEDs
Manual
or
Auto
are lighted up,
this indicates the operation mode the emission controller is currently in.
The emission controller must be in manual mode to download a configuration from the MICT to
the device. In automatic operation, the MICT can only be used to display the data and to create
log files.
Risk of destruction!
In manual operation, the signals of the master control are not analyzed. If
you make any adjustments in the manual mode with the gas engine
running, make sure that these settings do not endanger the correct
operation of the gas engine.
Summary of Contents for VariSCR
Page 1: ...VariSCR NOX Emission Controller Operating Manual P N 01 50 025 EN Rev 06 2020...
Page 111: ...Rev 06 2020 111...
Page 112: ......
