Using the ESPE as a presence sensing device
The main function of a protective device used for presence sensing is to keep the machine in a safe state as long as a person or part of it is within its sensing area.
The sensing area must therefore be configured so as not to allow for a person to remain within the hazardous area or to a distance below the stated safety distance without being detected.
If the ESPE only performs the presence sensor function, it must be used in combination with other safety measures (eg interlocked shield or crossover sensor) to ensure that the machine is in a safe state before it is possible access it.
In dimensioning the protected area, additional protective measures shall be implemented in addition to computing the safety distance, to prevent that a person can circumvent the protected area.
It shall not be possible to reach the dangerous area by climbing on the machine or crawling below the sensitive area or leaning over the edge of the sensitive area.
The parts of the machine not guarded by the ESPE, shall be protected by means of solid repairs (e.g. interlocked guards if can be removed to allow access for maintenance).
Unexpected start-up of the machine shall be prevented after a person has passed through the detection zone of the trip device to the hazardous zone of the machine.
Suitable methods are:
- Barriers to ensure that a person cannot approach the machine hazard from directions not protected by the protective equipment
- Provision of a restart interlock
- Provision of a presence sensing device
- Measures to prevent a person being present between the protective equipment and the hazardous zone.