Project "Conveytrac"

Status: Completed Successfully

Client: Conveytrac
Start date: 02-Mar-2012
End date: 19-Mar-2012
Project: Conveytrac
Scope of work:
Automation Works was contracted by Conveytrac to Design, manufacture, deliver, install and commission a fully automated Slat Conveyor at Sappi’s Entra Mill in Springs.
Equipment used:
1 x S7 Panel
1 x …Panel
1 x Siemens S7-200 CPU
1 x Expansion module
1 x Class 4 Allan Bradley Emergency Stop Relay
4 x Siemens Micromaster M440 VSDs
12 x Banner Diffused Sensors
Indication Lamps, Terminals, Labels, relays.\
Design: A S7 panel was fitted with 4 x Siemens Micromaster M440 4kW VSDs, to drive 4 x 2.2kW motors. A Siemens S7-200 PLC with an Expansion module was scoped to perform all the required automated operations of the Conveyor system. A 2-way Selector switch – Auto/Manual, was fitted in the inside of the panel as a security measure. A Class 4 Emergency Stop Relay was fitted to ensure optimal reliability of the Emergency circuit. Fast Blow fuses were used in the 380V Supply circuit and monitored through the VSDs via the PLC. Two Cooling fans were also mounted to ensure heat dissipation from the components within the panel. The Main Panel door housed the Operation Selectors and Indicators, namely: A Key Selector switch – used to activate direction, Directional indicators – Forward/Reverse, Auto/Man indicators, E-Stop Button with an accompanying Indicator, 4 x Manual selector switches to activate the conveyors manually, A Reset pushbutton with a general alarm indicator.

A smaller panel was mounted at the other end of the
Installation: The Conveyor is fitted with 12 Banner Photoelectric diffused sensors that are used to provide an input to the PLC to indicate a pallet is present on the conveyor.

The controls at the panel are configured / selected for the type of operation required, namely: Auto/Man mode from within the panel, the direction selector switch is activated and the direction selector button is pushed to acknowledge the desired direction. Both Direction switches on each panel must be activated to select direction (Safety measure for operators).

The end Conveyors are each fitted with a sensor to acknowledge the presence of a Fork truck, each end limit respective of direction is doubled with a hardwired final sensor to ensure safe operation at the ends in the instance a sensor fails. Each conveyor is fitted with two sensors, one at the Beginning of the conveyor travel and one at the End of the conveyor travel.

The fork truck will place a pallet on the end conveyor or conveyor 1, the fork truck present sensor and the first conve
Commissioning: The following tests were performed to ensure proper operation of the conveyor system.

1. The Emergency Circuit was tested by activating the E-Stop buttons on the main panel, small panel and the emergency rope cables on the side of the conveyor. In this mode there is no activation sequence and the conveyor simulates an “OFF” state, irrespective of which emergency switch was triggered.

2. The Reset button was tested by acknowledging that the emergency circuit was activated and deactivated, once pressed the conveyor will continue normal operation.

3. The Auto/Manual mode was triggered and the correct indicators were checked to ensure clear indication.

4. The Direction, Key selector switches was activated and the corresponding indicators were observed. Each Key was activated separately to ensure no conveyor operation unless both key selectors were placed in the correct orientation, in this state the Direction Selector button is pressed to acknowledge the desired direction. The key switches were then switc