Technical data

Working Out the Automation Concept
3.3 Describing the Individual Functional Areas
Programming with STEP 7
Manual, 05/2010, A5E02789666-01 63
Agitator Motor
The agitator motor mixes ingredient A with ingredient B in the mixing tank.
• Rating: 100 kW (134 hp) at 1200 rpm
The agitator motor is controlled (start/stop) from an operator station located near the mixing tank. The number
of starts is counted for maintenance purposes. Both the counters and the display can be reset with one button.
The following conditions must be satisfied for the pumps to operate:
• The tank level sensor is not signaling "Tank below minimum."
• The drain valve of the mixing tank is closed.
• The emergency off is not activated.
The pumps are switched off if the following condition is satisfied:
• The tachometer does not indicate that the rated speed has been reached within 10 seconds of starting the
motor.
Drain Valve
The drain valve allows the mixture to drain (using gravity feed) to the next stage in the process. The valve has
a solenoid with a spring return.
• If the solenoid is activated, the outlet valve is opened.
• If the solenoid is deactivated, the outlet valve is closed.
The outlet valve is controlled (open/close) from an operator station.
The drain valve can be opened under the following conditions:
• The agitator motor is off.
• The tank level sensor is not signaling "Tank empty."
• The emergency off is not activated.
The pumps are switched off if the following condition is satisfied:
• The tank level sensor is indicating "Tank empty."
Switches for Tank Level Measurement
The switches in the mixing tank indicate the level in the tank and are used to interlock the feed pumps and the
agitator motor.