AC STAG-4 QBOX BASIC, User Manual, Page: 27 / 65

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Petrol switch-over - parameters related to switching from petrol to LPG.

Min gas RPM
– min rpm; when lower, the controller will switch over to petrol.

Max gas RPM
– engine rpm; when higher, the controller will switch to petrol.

Pressure error delay
– amount of time with the LPG pressure lower than minimal before
the controller switches to petrol and reports: “LPG pressure too low”.

Intelligent press. drop service
– the function allows to utilize gas residues in the LPG
tank.

Min. gas temp.
– min. LPG temperature; when lower, the controller will switch over to
petrol.

Max load on gas
– the maximum load value in the LPG mode, above which the controller
switches to petrol. This option is very useful for the engines in the case of which petrol
injectors can be fully opened. In such a situation, the LPG controller can only open LPG
injectors permanently as well. However, corrections, e.g. resulting from changes in the
LPG pressure, will be no longer possible. The moment when petrol injectors are fully open
corresponds to the load value of 100 [%]. If petrol injectors become fully open, the “
Max.
load on gas
” parameter should be set to approximately 95 [%]. This will result in the
controller switching to petrol before full opening of LPG injectors.
Calibration parameters
–
parameters related to controller calibration.

Operational pressure
– LPG pressure at which the controller was calibrated. This setting
can be altered manually. However, each change of the operational LPG pressure
requires multiplier map calibration!!!

Minimum pressure
– when the pressure is lower than minimum, the controller will switch
to petrol if the duration of min. pressure exceeds the Pressure error delay.

Gas temp.
– gas temperature at which the controller was calibrated. It is impossible to
manually change this parameter.
Remaining parameters in the LPG Controller Settings group :

Gas injector type
– type of the LPG injector.
Changing the injector type requires re-
auto-calibration or multiplier map calibration!!!
Clicking the Gas Injectors Settings button will open up the following window in
which the LPG injectors can be calibrated:
Fig. 19 Gas injectors settings window