Padlocking or consignment of equipment
The most cited means in the literature to keep maintenance workers safe is padlocking (term used in Quebec) or consignment (term used in France).
This means is described in detail in the ISO 14118:2000 standard [ISO 14118:2000] and in the INRS guides on means of prevention against mechanical risks or on lockout and de-lockout [ED 754, Lupine 2006]. but is only described very briefly in the RSST
[RSS]. However, there are several explanatory documents published in Quebec [ASPME 1998. ASSIFQ 2001, Daoust 2003].
The term padlocking is often used to describe means of protection temporarily put in place on equipment or machines. The frequent use of this term and the pictorial nature of this word present an ambiguity in the interpretation of this prevention tool.
The definition that seems most accurate today for padlocking is: “a set of provisions which make it possible to secure and maintain equipment in such a way that a change of state is impossible without the voluntary action of all the speakers [Lupin]. Such a description is general because all the measures and lockout instructions remain specific to each company or each machine and can take many forms.
Preventing start-up
Keeping a machine stationary while people are in dangerous areas is one of the most important conditions for the safe use of a machine and, for this reason, one of the designer’s priority objectives. and the user of the machine.
The main stages of padlocking
The main stages of lockout depend in part on the needs expressed by the company, the objectives to be achieved, particularly in terms of security and the constraints that apply.
This explains the difficulty of having a standard procedure model for padlocking [ED 754].
To be effective and safe, a lockout procedure must therefore be adapted to the equipment, the interventions to be carried out and the constraints encountered [Poulin 1999].
However, it is possible to identify three main stages (Table 4) [Construction 1995]: A preliminary phase during which an inventory of equipment and energy sources is carried out to develop lockout strategies taking into account the specificities and constraints encountered. This phase also includes identification and coding of the various elements previously inventoried and requiring padlocking. The lockout sheets (which also include unlocking) must be developed at the end of this preliminary phase;
A lockout phase where the equipment is stopped, separated from its energy sources and padlocked. We will also carry out a release of residual or accumulated energy on the equipment and a step of verifying that the machine is properly secured;
A phase of unlocking, after intervention, with the removal of the various protection devices previously applied, the replacement of the various elements which have been removed, activated or moved such as protectors, stop buttons or parts and the reactivation of the equipment. This unlocking phase can be relatively simple if the intervention was short but can become very complex if the machine has been substantially modified.
In addition, the lockout must be carried out by trained people [ED 754] and a formal phase of handing over the equipment to production must complete everything.
The three main stages of padlocking.
Stage :
- Preliminary
- Padlocking
- Unlocking
Actions
- Inventory of equipment and energy sources
- Identification
- Codification
- Development of wise padlock sheets
- Equipment shutdown
- Separation of energy sources
- Condemnation (cu padlock wise)
- Release of accumulated energies
- Safety check
- Reassembly of equipment
- Removal of lockout devices
- Refeeding the machine
- Verifying correct operation
- Delivery of equipment to production
The regulation in Quebec on padlocking
In Quebec, the Regulation respecting occupational health and safety [RSST] deals with lockout in two of these articles.
Article 185 of the RSST states that “before undertaking any maintenance, repair or unblocking work in the hazardous area of a machine, the following safety measures must be taken, subject to the provisions of article 186:
- placing the machine control device in the off position;
complete stop of the machine; - the padlocking, by each person exposed to danger, of all energy sources of
- the machine, so as to avoid any accidental starting of the machine during the duration of the work.
In fact, padlocking is recognized as being the first way to secure a machine on which human intervention is going to be carried out.
