Nilfisk-Advance America GB 1133 instruction manual the red warning light flashes up

9 Adjusting the automatic gear change of the minimum airflow

Use the performance profile to adjust the cutoff point for the minimum airflow of extractors. First of all, find out the minimal airflow that ensures

agood operation of the dust-producing system. Mark this value on the x- axis, then draw a vertical line from here to the curve. Now draw a line parallel to the x-axis from the point of intersection to the y-axis. This value describes the vacuum that has to be adjusted at the vacuum switch when the minimal airflow is no longer sufficient.

When adjusting the vacuum, you have to connect an appropriate measuring device parallel to the vacuum switch. Throttle the airflow at the suction inlet until the required value is reached. Now calibrate the cutoff point by the adjusting screw of the vacuum switch.

When the minimal airflow falls short, the following happens after a few seconds:

-the red warning light flashes up.

-the floating contact in the switch housing switches. This contact (6 A at

a

voltage of 230 V, AC11) manages the connection of the control circuit of

the dust-producing system to the extractor or to control an external optical or acoustical signal.