5.5 K-factor for the suction rate
The K-factor for the suction rate corrects the difference in the flow characteristics of
air and petrol vapour. This correction is necessary as the suction system will be initially
measured with atmospheric air, and will later be operated with petrol vapour.
The K-factor is an installation-specific variable. It is determined as the quotient of the
volumetric flow rate of air to the volumetric flow rate of petrol vapour.
Further information regarding the determination of the K-factor can be found in the
operating instructions for the Type MKNE-1094 manual unit (under the chapter „In-
troduction to the Technology of Vapour Recovery" and the paragraphs „Information
regarding the volumetric flow rate..." and „Determination of the correction factor").
5.6 Pump after-run time
The pump after-run time is the delay time for the vacuum pump, and lies between the
end of the refuelling procedure (the closing of the proportional valve) and the switch-
ing-off of the vacuum pump. As a result of the after-run time of the pump, any petrol
vapour still remaining in the piping will be sucked out.
5.7 Petrol pump operation
During the calibration, the controller automatically registers the non-linear valve cur-
rent gas flow characteristic of the complete petrol pump installation, stores the char-
acteristic points, and automatically carries out a linearisation of these characteristics
through linear interpolation. The control of the sucked-in petrol vapour quantity takes
place using the linearised characteristic.
After the calibration, the petrol vapour displaced while filling the tank will be automati-
cally sucked in via the suction line on the pump pistol.
NOTE
6 MAINTENANCE AND TROUBLE-SHOOTING
6.1 Maintenance
The electronic controller for vapour recovery is maintenance-free when operated in
accordance with the instructions given in this manual.
6.2 Faults
Fault
Unit does not function
("Operating voltage on" LED = dark)
12 - 1094
The mode of operation of a petrol pump is described in detail in the
chapter "System description".
Cause
Correction
No operating
Check the electrical
voltage
power supply
Fuse defective /
Replace the fuse
blown
(wire fuse, 0.4 A
slow-blow)