Standards and Safety
Core concepts
Understand the machinery safety framework: risk assessment, risk reduction, and the hierarchy of controls (inherently safe design, safeguarding, information for use). Know the role of harmonized standards, the concept of essential health and safety requirements, and the CE marking process including the declaration of conformity and technical file. Understand safety functions and performance levels, emergency stop requirements, guard interlocks and two-hand controls. Know electrical safety basics: protection against direct and indirect contact, protective earthing, and residual current devices.
Traps in questions
- Believing CE marking is a quality mark rather than a conformity declaration.
- Confusing a risk assessment with a risk analysis.
- Assuming an emergency stop is a substitute for guarding.
- Forgetting that the technical file must be retained after delivery.
- Mixing up standards for machinery with standards for electrical installations.
Worked example
A robot cell needs a risk assessment. Steps: define limits of the machine, identify hazards (crushing, ejection, electrical), estimate risk, reduce risk by design (fencing), then by safeguarding (interlocked door, light curtain), then by information (warnings, training). Residual risk must be documented and the conformity declaration signed. Rule of thumb: design out first, guard second, warn third.
Practical competence
Be able to describe the CE process, name the documents in the technical file, and explain the difference between a guard, a protective device and a warning. Understand that safety functions must be validated, not just installed.