According to the safety document, it was decided to record the temperatures at various points on the bucket loaders. The PLC must check:
- The actual bearings temperatures of the 11 bucket loaders.
o Two bearings at the bottom and two at the top
- The actual ducts temperatures of the 11 bucket loaders and on two levels:
o Upper part, on the outside of the cap, upwards, on both sides of it.
o Lower part, at the level of the hoist strap, outside, on both sides of the foot.
- The temperature of the cooler duct, measured at 2 separate points:
o These temperature measurements will be placed at the end of the filter.
- The temperature of the crusher filter duct, at 2 separate points.
- The temperatures of the crusher bearings, at 2 distinct points:
o On one side of the motor
o A side opposite to the motor
The acquisition of values is carried out by temperature probes. The PLC must manage two temperature thresholds per probe:
- The first threshold indicates a warning, without consequences for the installation.
o An orange indicator light is on.
- The second threshold triggers a fault which immediately stops the bucket loader concerned.
o A red light comes on. Restarting can only be done once the probe has returned below the fault threshold.
To restart the bucket loader, a fault acknowledgment is mandatory.
All the information must be viewable on the supervision computer. Its function is to configure and acknowledge faults. The supervision tool must have:
- 1 main page which shows the 11 bucket loaders
- 1 page for the chiller and crusher (for probes display)
- 1 page per bucket loader with its information on temperatures, thresholds (8), running time (2 including 1 with RESET SUPERVISOR level, CR speed and its thresholds, delay before faults (9 values).
- Display faults.
- Probe calibration
The screen must offer several authorization levels, namely:
- OPERATOR: To view the motors, the safety elements and to acknowledge the faults.
- SUPERVISOR: To configure the time delays and fault tripping thresholds.
- ADMINISTRATOR: For full access to the available settings data.
All the data will be put in a SQL-type database in order to obtain a traceability as close as possible to actions and monitoring events.