Safety Devices
A safety device is a tool or mechanism designed to protect individuals from accidents, harm and danger. From personal self-defense devices to robbery prevention technology, these safety tools help reduce risk and save lives.
Modern machine safety devices are effective in a variety of environments and meet strict industry standards. However, they’re not always used properly.
Ground Fault Circuit Interrupters
Ground Fault Circuit Interrupters (GFCIs) are electrical receptacles that shut off electricity within milliseconds as a safety precaution. They do this by comparing the amount of current going to and returning from equipment along circuit conductors, and when there is a difference, it trips the device. GFCIs are designed to protect people against the most common type of shock hazard, a ground fault. However, they do not protect against line contact hazards (people holding two "hot" wires or a hot and neutral wire in each hand, for example), or from appliances that have built-in GFCI protection (such as hair dryers).
Most electricians know that GFCIs protect people using electrical equipment where water and electricity are likely to come in contact with each other. They are typically installed in areas like kitchens, bathrooms, garages, basements, swimming pools, and outlets and fixtures in the outdoors. They are also required for receptacles used with cord-connected appliances in residential dwellings, in some commercial buildings, and in other locations as specified by the National Electric Code.
There are a few types of GFCIs. One, called a Class A GFCI, provides personnel protection by operating when the leakage current to ground exceeds 5 milliamperes. The other, called a Class B GFCI, provides equipment and circuit protection by operating when the leakage current to the ground exceeds 20 milliamperes.
GFCIs are different from standard circuit breakers that are commonly found in homes. A typical circuit breaker shuts off power when the current in a household circuit becomes too high, which helps prevent overheating and fire. A GFCI or RCD, on the other hand, turns off the current when it detects that some of it is traveling through a person's body, which can cause shock and electrocution.
Safety Laser Scanners
Unlike light curtains that detect motion with optical sensors, safety laser scanners use infrared to detect human bodies. The scanner floods the area with laser light and then monitors reflected signals to create a two-dimensional line-of-sight map of the area.
As soon as an object moves in the detection field, the system responds with a warning or alarm signal to alert workers. The scanner can also prevent machine start-up by shutting down the system when a person is detected in its protective zone. Depending on the type of scanner, configuration software allows you to set multiple warning zones and a final protection zone to limit undetectable areas.
In addition to protecting operators, safety laser scanners can be used to protect the equipment itself from external damage. lone worker system For example, a robotic welding cell can benefit from safety laser scanners to prevent accidental collisions with workers or products. Safety scanners can also be mounted on automated guided vehicles (AGV) to prevent them from colliding with people or obstacles.
The global safety laser scanners market is segmented based on end user, deployment type, and technology. The end users include automotive, food & beverages, healthcare & pharmaceuticals, and consumer electronics. The automotive sub-segment is expected to dominate the overall market in terms of revenue share in 2022. This is attributed to the increasing usage of safety laser scanners for robotic work cells, automation of assembly lines, and pallet transfer conveyors. The programmability of safety laser scanners also contributes to their demand in the market. These devices are compatible with a wide range of programming languages and can be modified to meet the specific requirements of different industries. Additionally, they comply with the IEC 61508: SIL 2 standard.
Interlock Switches
Safety interlock switches monitor the status of doors, guards and gates to ensure they are closed before a machine can start. When these devices are tripped, they can shut off the power to that part of a system. This can prevent both human injury and equipment damage. These are commonly used on machines that require the operator to enter a hazardous area, such as material handling or packaging lines.
They can also be used to keep robots from operating while workers are inside the case of a machine. This way, workers can open the door and close it to resume work on the machine without risking their lives. KEYENCE offers safety interlock switches (GS Series) in several different sizes, contact configurations and functions to meet your needs.
These mechanical safety devices include single-pole double-throw contacts and changeover contact pairs that are positively driven. An integrated actuator monitors the position of movable components, and the movement of this component triggers the switch. A control unit manages multiple solid-state outputs, and the actuators are coded to prevent tampering. These devices are available in various materials, including aluminum and stainless steel for heavy-duty applications, and plastic for washdown environments and swing doors with misalignment issues.
When choosing a safety device, be sure to select one with a Safety Integrity Level rating (SIL) that matches your application requirements and industry safety standards. The higher the SIL number, the more reliable it is in terms of its ability to prevent dangerous failures. Light and color indicators are other quick ways to get real-time safety status feedback. They are highly visible, can be placed inside hazardous areas and are customizable to signal whatever properties your application requires.
PSR
Safety devices ensure adherence to industry-consensus safety standards and regulations while also preventing accidents, injuries, and downtime. These machine safety products are an integral part of any facility's operations, and by properly using them, you can maximize productivity while ensuring worker and plant safety.
Lock Out/Tag Out devices are designed to neutralize all potential energy in a machine prior to and after maintenance or operator interaction with it. This helps to prevent unexpected bursts of power that could injure maintenance technicians and workers in proximity to machinery during startup or operation. These devices can include a variety of options, such as locks that enforce manual locking/unlocking routines before and after machine use or tags that employ coded colors to indicate machine status.
Interlock switches are tamper-resistant devices that stop machines from operating when access doors or other points of entry have been opened or removed. This type of safety device is a necessary complement to other types of machine guarding and offers an additional layer of security that helps reduce risk for employees who operate or maintain hazardous equipment.
Light curtains and laser scanners create invisible barriers of sensors and beams of light that monitor for unauthorized movement near machine hazards. If the hazard is approached, these sensors will interrupt all machine motion and shut off the hazard automatically to help prevent injury.
Emergency stops and pull ropes allow operators to halt dangerous machinery instantly by pressing a button or pulling a cord, offering a quick failsafe mechanism that can override other control systems. These devices are easy to use, highly visible, and can be customized with different colors and other safety information to meet specific requirements.
Light Curtains & Laser Scanners
Safety light curtains are the most common type of non-contact machine guarding solution, with solutions available for point-of-operation, area, and perimeter protection. These systems monitor open access and intervention points to danger zones by sending out a continuous stream of infrared rays that detect any interruptions within the protective field. Any violations of this barrier trigger a safe shutdown command, shutting down plant and machinery.
For this reason, they are well-suited to protect a large area of your production line and can even detect items that may be moving as products pass through the barrier, such as bottles or pallets. They are also able to be muted, a function that prevents the safety function from activating as objects move through the protected area. Muting sensors are usually photoelectric or inductive sensors that are logically evaluated to determine the sequence of the object passing through, and the safety light curtain only activates when the correct sequence has been detected.
Another option is safety laser scanners, which are a good choice when you need to detect operators but have limited space to mount a light curtain. These devices detect any operators without any contact, making them immune to damage from dropped items or people stepping on them, and they’re able to be mounted in a horizontal configuration that allows them to protect complexly shaped areas.
Like light curtains, safety laser scanners can be muted using a combination of photoelectric and inductive sensors. However, safety laser scanners have the advantage of being able to evaluate individual interruption patterns and identify whether or not an object is a person or just material. This approach is much more effective at reducing false positives than using the muting function of a light curtain and requires less mechanical mounting effort and wiring.
