What is the importance of the EQMT (Equipment) Isolation tab in the Permit to Work (PTW), in OHS Online?
A very good question! The Equipment Isolation tab of the PTW must be selected whenever any electrical installation or equipment is to be worked on or whenever any machinery is to be worked on by the contractor as part of the work being done for the PTW. This type of work is considered 'high risk' because of the high likelihood of persons coming into contact with either electricity or with moving parts which are under force.
GENERAL RISKS POSED BY INSTALLATIONS, EQUIPMENT AND MACHINERY
Whenever work is conducted on machinery or equipment (or installations), the process requires the interaction of the worker with the actual parts of the machinery. These parts are often designed to move repeatedly and with great force (energy), the motion of which can cause severe injuries to the worker should the machinery be allowed to operate when the worker is working on it. Examples of common machinery hazards and their risks are shown below:
THE RISKS POSED BY ELECTRICAL INSTALLATIONS OR EQUIPMENT
When the work being done includes working on electrical installations, equipment or machinery, the main hazards posed to the worker(s) include:
1. Electrical hazards - These hazards include electrical cables, lines or circuits which may still be 'live' and have electrical energy flowing through them, posing a risk of electrocution for the worker working on them. In addition to these, there is also the electrical risk posed by residual electrical energy sources, such as batteries and capacitors, which need to be discharged before work can commence.
2. Mechanical hazards - These hazards include those physical hazards described in the section above but also include residual energy sources associated with the machinery, such as hydraulics, pneumatics, gravitational energies, etc. 3. Non-mechanical hazards - These hazards include factors such as dust, explosive or flammable atmospheres, heat (which may radiate or conduct), steam, chemicals, ignition sources, noise, vapours and fumes, molten materials, etc.
THE RISKS POSED BY MECHANICAL INSTALLATIONS OR EQUIPMENT
When the work being done does not include any electrical aspects, the main hazards posed to the worker(s) include:
1. Mechanical hazards - These hazards include those physical hazards described in the first section but also include residual energy sources associated with the machinery, such as hydraulics, pneumatics, gravitational energies, etc.
2. Non-mechanical hazards - These hazards include factors such as dust, explosive or flammable atmospheres, heat (which may radiate or conduct), steam, chemicals, ignition sources, noise, vapours and fumes, molten materials, etc.
The hazards and risks associated with working on electrical equipment and machinery make the need for their isolation prior to any work being done on them, a crucial part of safely managing the process so the work performed is done so with minimal risk. This is where the lockout/tagout process becomes extremely important. The lockout/tagout process is designed to prevent the accidental starting of equipment while a person is working on it. The main aspects of a lockout/tagout process include the following:
1. The shutdown of equipment and machinery being worked on.
2. The identification of all energy sources and other hazards.
3. The identification of all isolation points.
4. The isolation of all energy sources.
5. The de-energising of all residual (stored) energies.
6. The lockout of all isolation points.
7. The tagging of machinery controls, energy sources and other hazards.
8. The testing and confirmation that the equipment cannot accidentally start by trying to reactivate it (isolations are effective and residual energies have dissipated).
By locking out equipment to prevent its accidental starting and tagging it to inform potential users of its current status, the risks of the worker being harmed on the equipment or machinery, through accidental starting, are drastically reduced. The Equipment Isolation section helps to ensure standard checks, relevant to isolation processes, are made and also that necessary lockout/tagout process controls are managed and are in place too.