As human behaviour is heavily influenced by experiences, training and procedures, any system or procedure dependent on human interaction will be subject to the peculiarities of individuals and their level of risk tolerance. Complacency, inattention, misunderstanding or other human shortcomings can also directly compromise safe work practice despite processes being implemented.
To counteract these issues, automated and remote isolation systems have been engineered and introduced into mine site operations. Engineering solutions routinely employ automation to simplify and control plant operation and can be applied to procedural safety and operational management.
The implementation of automated isolation provides a significant improvement to overall site safety and ensures isolation is done the same way every time – as per system design specification, providing a consistent and efficient approach that minimises human intervention and eliminates margin for human error.
As with any automated system, there are also immediate productivity improvements. In the case of automated isolation, the gains are realised in two ways: through a decrease in the required level of competence of operators, eliminating the need for high-level electricians, and by decreasing handling and travel time associated with manual isolation.
Ampcontrol’s Remote Isolation System for conveyors
Through the installation of Ampcontrol’s innovative, 3-wire system, remote and automated isolation can be undertaken by one operator in minutes, from the location of the breakdown. This is a marked improvement over manual isolation which requires travel to the isolation points, as well as the involvement of an electrician. As conveyors increase in length and complexity, the benefits of isolating remotely also increase. Manual isolation on even short conveyors can take 30 minutes. The reduced effort required by an operator of an automated system also removes motivation for shortcuts to override or manually intervene in the proper isolation process.
Remote isolation is easily integrated into existing site procedures via the use of personal locks or group lock boxes. It can achieve up to SIL2 compliance as part of a system assessment.
Equipment utilised in Ampcontrol’s remote isolation systems includes iMAC monitoring and control units, pull keys, and Voicecom communication devices. By utilising iMAC’s remote IO capability, it is possible to integrate other control equipment such as belt wander,speed monitoring or temperature inputs.
As Ampcontrol’s pull key devices are located along the entire length of the system there is no need for a central control station, allowing faster response times and safer personnel movement.
Ampcontrol’s remote isolation system manages notification of isolation/s via the pullkeys, to provide swift notification of isolation both to the instigating operator and other personnel working on the conveyor. Ongoing audible isolation status updates continue to inform the condition of the equipment.
Ampcontrol’s Outlet Cassette System
The traditional means of isolating an individual outlet has been to open the main circuit breaker, earth the main bus then remove the plug and place into an earthing receptacle. There is a potential for the cable to still carry a static charge of sufficient energy to ignite gas or cause an electric shock.
Ampcontrol has developed the outlet cassette system to provide isolation and earthing to each individual outlet. The operation of the process is automated via PLC control.
The earthing system is designed and verified to a Safety Integrity Level 2 verified by third party using calculation methods provided in AS61508 and AS62061. Operational testing was conducted with 10,000 operations of the cassette without any appreciable wear or deterioration of the electrical properties. The OCS eliminates the inherent risks involved in manual isolation by providing a physical isolation from the electrical supply and applying a visible connection to earth for the outgoing circuit. It removes exposure of the residual capacitive charge to the operator and the explosive environment, providing a positive lockable earth position for electrical work.
Ampcontrol’s standardised cassette design also provides a compact solution for individual outlet isolation and visible earthing, without the cost and space required by discrete isolators and earth switches.
Through thoughtful design of the cassette, maintenance for the control equipment is simplified substantially, further increasing productivity gains.
Implementing Ampcontrol’s automated and remote isolation systems ensures a safer, more efficient and productive operation. Find out more.