The first edition of CSA Z462, Workplace Electrical Safety, was published in December 2008. The purpose of this Standard is to specify the requirements for a safe distance area for workers relative to the hazards associated with the use of electricity within the workplace.
The limits of approach to an energized conductor or circuit part must be determined by analyzing the hazards associated with electrical shock and arc flash. The following diagram shows the approach boundaries and spaces that need to be identified.
Figure: Approach boundaries and spaces.
Clearly, lockout is required when working with electrical conductors or circuit parts unless additional or increased hazards result from de-energization or the task cannot be performed in a de-energized state due to equipment design or operational limitations.
Significant Inclusions & Safety Requirements
Users of mechanical power presses in the USA now have a new standard that replaces ANSI B11.1 2001. ANSI B11.1 2009 Safety Requirements for Mechanical Power Presses include some significant additions from the previous Standard.
This new Standard deals with transfer presses, tandem line presses, presses used in production cells, automatically fed presses, as well as manually fed presses.
New requirements for risk assessment and risk reduction have been added for complex automatic press production systems with the use of perimeter safeguarding. Complex press production systems often include scrap chutes and moving bolsters which have also been addressed in the Standard.
The Standard has been revised to recognize the recent technology of servo systems to directly drive a press. These mechanical presses are often called servo presses or direct-drive presses and allow the press operator to modify the stroke motion for process control.
Slide locks have also been recognized in this Standard. Like safety blocks, they are intended to prevent the slide (ram) from descending unintentionally. A slide lock is a mechanical engaging device applied to a mechanical power press that is designed to support the maximum anticipated load.
Large safety blocks are often heavy and/or awkward to put into position on the bolster and therefore, are not consistently used by many press operators. Slide lock devices generally require much less physical effort to install and remove than safety blocks and can be used in place of them.
