AS NZS 4871.4:2010 – Electrical equipment for mines and quarries Part 4: Mains powered electrical mobile machines.
(I) A system to override the trip mechanism may be provided to allow the safe withdrawal of the machine for repair and maintenance. Only functions necessary for the safe withdrawal shall be enabled.
(g) Access to the override or reset mechanism should be restricted to authorised personnel.
I The relevant regulatory authority may require gas monitoring systems to bc tittcd to the machine
2 Sonic regulatory authorities ma require audible and visual warning when a predetermined gas lcvel is reached.
2.6.1 General
Controls on all machines shall be located so they arc within easy reach of the operator.
Consideration should be given to sound ergonomic principles for location and means of operation.
Where dual-driving cabs are tilted to machines. a control direction device shall be fitted and set to give control to one driving cab and to immobilize the controls in the second driving cab.
Where two or more machines are connected together to operate in tandem-
(a) one machine shall be the master from which all controls (for all machines) are to be ccntrali,cd—other controls not required for safety shall he ncutrali,ed:
(b) thc control system shall be designed to fail-to-safety; and
(c) the emergency braking in each machine shall operate all machines connected in tandem.
Where more than one control station is fitted to a machine, or where multiple machines are connected together, the operating logic between each of the control stations shall be subject to a risk management process.
2.6.2 Emergency stop dcv ice
Machines shall have an accessible emergency stop device(s) located for easy access during all modes of operation.
Emergency slop devices shall comply with the requirements of ASINZS 4871.1.
2.6.3 Dead man control
Where ‘dead man control is required its operation shall stop travel movement and bring the machine safely to rest. The dead man system shall be subject to functional safety analysis. refer to AS/NZS 4871.1.
2.6.4 Reversing alarm
Reversing alarms are required. except for machines generally driven equally in both directions. Reversing alarms shall be audible and sound continuously while the vehicle is in reverse mode. In addition, visual alarms may be required, based on a risk management process.
2.6. Pre-start alarms
A pre.start alarm shall be fitted and operate prior to machine starting. The alarm shall be audible and sound for a time determined by a risk management process before any movement occurs. Other audible alarms may be required to indicate hazardous movement subject to risk management process. In addition visual alarms may be required based on a risk management process.
Pre-slart warning alarms shall be operational regardless of what form of control has been selected.
2.7.1 General
The following interlocks are not all required on all machines, but the information provides a guide to what may be required on individual machines. The need for any particular safety interlock shall be determined by risk management process.
2.7.2 l)oors
Where driver compartments are fitted ssith hinged access doors, an interlocking device shall be fitted to stop the machine movement while the doors are open, and apply the brakes to prevent machine ‘run away’.
2.7.3 Waler floss
Where a flow of water is required. e.g. dust suppression. pick ignition and cooling, a flow monitoring device shall be fitted to pre%ent machine operation unless a predetermined how of water is asailabic on the machine.
NOTE: Some machines may require a pressure sss itching device in addition to the above.
2.7.4 Roof bolting
Where a machine is fitted with roof bolting equipment, an interlocking des ice shall be fitted to stop all hazardous movements of the machine before the roof bolting can commence or to stop the roof bolting when machine movement is required. This switching device shall be within easy reach of the bolter operator.
2.7.5 Control-niode
Where control-mode is selectable, the selected mode of control shall he visible and clearly marked. Emergency stops shall shut down all control functions irrespective of the control mode selected. Other safety stops shall shut down all associated control functions.