Technical Information
26
S 2xx, S 3xx & S 4xx Canister Vacuums
S 4xx series:
Power control on automatic models is via a negative pressure switch
combined with appropriate electronics.
Laboratory experimentation has shown the optimum level of the ratio of
suction power to electric power. The efficient automatic method of operation
acts to maintain this level and forms the basis of the software-controlled motor
power control.
The negative pressure switch has upper and lower switching points. These
switching points act to introduce breaks in the power curve.
If the lower switching point is reached, the control system switches to high
power. Conversely, if the upper switching point is reached, power is reduced.
During phase-chopping control, the triac is electronically controlled.
4.4.3 Booster
Setting
Models S 346i - S 348i:
When the booster button is pressed, the electronic control operates the motor
at its maximum power setting for 10 seconds. This function can be chosen
twice in succession. A third attempt to operate this feature will not be
accepted. In this case the booster LED flashes as, after a second boost, the
electronic control introduces a pause of 60 seconds before the booster
function can be operated again.
With models S 445i - S 448i, the triac for phase-chopping is controlled
electronically.
Power is controlled via the +/- buttons on the foot switch assembly.
When the booster button is pressed, the electronic control operates the motor
at its maximum power setting for 10 seconds. This function can be chosen
twice in succession. A third attempt to operate this feature will not be
accepted. In this case the booster LED flashes as, after a second boost, the
electronic control introduces a pause of 60 seconds before the booster
function can be operated again.
During automatic operation, the negative pressure switch assumes power
control.
