Pump Rack - GE Druck ADTS 405 Service Manual

Druck ADTS 405 Service Manual

Pump Rack

26. The rack pump consists of an electric motor driving a pump and controlled by a controller PCB.
The rack is cooled by an electric fan. A power supply unit produces electrical power for the motor
circuit, fan and circuits to the electronics rack. The electrical supply connector, power switch, elapsed
time indicator, fuses and auxiliary pneumatic connections are located on the front panel of the rack.
27. The pump is driven by a brushless DC motor, Hall effect sensors provide feedback to the motor
drive circuits.
28. The pump consists of four reciprocating pistons on a central eccentric. One piston head is
configured for pressure and the other three for vacuum. Reed valves in the piston heads control the
direction of air flow. One of the vacuum heads provides an initial (rough) vacuum that in turn feeds the
other two vacuum heads. The output of the pressure head is cooled and then passed through a
coalescing filter to extract any condensed water vapour.
29. One of the auxiliary pneumatic connectors is supplied by the initial (rough) vacuum, the other two
are for external input of vacuum and pressure or can be used as outputs of the pump.
30. The power supply unit receives power through a switch and fuse to produce 24 V DC for the
motor drive circuits and the power indicator.
Power supply
unit
K171 Issue No. 1
Figure 1-10 Pump Rack
Page 1-14
Fan
Filter
Motor
controller
PCB