Whilst trying out an isolation at an asphalt plant during a major regeneration project, a new Socomec safety enclosure isolator was discovered to be faulty, meaning the locked padlock could be removed whilst the system was isolated.
An asphalt plant engineer discovered whilst ‘trying out’ his isolation, that it was possible to remove his locked padlock from the isolator by depressing the handle past its ‘OFF’ position.
In the ‘OFF’ position, the isolator handle is turned downwards, and a lock applied to prevent the handle being switched back to ‘ON’. The handle also acts as a barrier to prevent the lock sliding to the right. This issue highlighted that the handle could be depressed so far that the lock could be slipped off the locking shaft. See image below
During a thorough investigation it was discovered that a square nut, which is intended to prevent the handle being depressed past its limit, had become loose and moved. This meant that the handle could be depressed further than intended, this allowed the padlock to ‘slip’ off.
As part of the company's continual drive to reduce risk, it has recently been introducing Socomec Safety enclosure isolators into the business. These isolators are a strong robust method of isolation offering better integrity and functionality than traditional alternatives. However, this incident has highlighted that, due to this manufacturing issue, there may be flaws in some models.