SACA Safety Systems and Functional Safety 3

Question 1

What is the primary function of a safety light curtain (light screen) in machine guarding?

Accepted Answer

To detect the presence of a person or object in a hazard zone and initiate a machine stop

Answer

A safety light curtain creates an electro-sensitive infrared detection field; when a person or object breaks the beam, it sends a stop signal to the machine's safety control system.

Question 2

What is the primary purpose of Lockout/Tagout (LOTO) procedures under OSHA 29 CFR 1910.147?

Accepted Answer

To control hazardous energy and protect workers during equipment servicing or maintenance

Answer

LOTO procedures ensure that all hazardous energy sources are isolated and locked out before servicing or maintenance begins, protecting workers from unexpected startup or release of stored energy.

Question 3

According to ISO 13849-1, Performance Level 'd' (PL d) corresponds to a probability of dangerous failure per hour (PFH) in which range?

Accepted Answer

≥10⁻⁷ to <10⁻⁶

Answer

PL d under ISO 13849-1 corresponds to a PFH range of 10⁻⁷ to 10⁻⁶ per hour, representing a high level of safety integrity commonly achieved with Category 3 or 4 architectures.

Question 4

What is the key distinction between an active and a passive safety system?

Accepted Answer

Active systems respond dynamically to detected hazards; passive systems provide protection without requiring activation

Answer

Passive safety devices (guards, barriers) provide continuous protection without being triggered, while active safety systems (light curtains, safety PLCs) detect hazards and respond dynamically to initiate a safe state.

Question 5

A two-hand control device on a machine press is designed primarily to:

Accepted Answer

Ensure both hands of the operator are away from the hazard zone before and during the machine cycle

Answer

A two-hand control requires simultaneous actuation of both controls by a single operator, ensuring both hands are occupied and therefore clear of the danger zone during the hazardous portion of the cycle.

SACA - Smart Automation Certification Alliance Practice Test

SACA - Smart Automation Certification Alliance Practice Test

SACA Safety Systems and Functional Safety 3