What is considered safe?
You've identified a piece of equipment that significantly improves productivity and solves a major ergonomic issue, but does it also introduce a safety concern? Common with most companies today, your primary position is maintenance, operations, production, engineering or shipping, and because you wear multiple hats, part time safety manager. Before you bring a new piece of equipment into your facility, get educated- find out what to look for, what's included and what standards need to be met for your company.
Where do you start?
You are frustrated trying to find vendors selling material handling equipment that are willing to meet a specification or able to talk machine safety, industry standards like UL508A, OHSA and ANSI. When they do talk they, take the stance that the safe operation of the machine is the responsibility of the purchaser, not the machine builder. Online search results show many companies that provide post-sale assessment and safety audit services to upgrade you system. Be careful this can delay implementation and lead to unwanted and unnecessary costs.
Who do you trust?
Cherry's Industrial has served the industrial warehouse sector for more than three decades with unique equipment that not only improves ergonomics but also the safety of employees and staff. Let our sales team, engineers and risk/safety management discuss safety concepts, guarding and devices. We can simply explain audits, certification types and important trends. Finally, we can build specifically to your company's standards.
So what's really important in machine safety design?
Risk assessments and safety audits identify the severity levels of hazards and pinch points. They also determine potential risks of injury that are present while the machine is operating, when someone is performing maintenance, or at rest. In this stage the customer’s safety manager works with Cherry’s Industrial on a matrix showing risks with and without guarding, e-stops and other safety devices. Safety categories 1-4 now have been updated to Performance Levels PLa, PLb, PLd and PLe. Confused? Don't be, Cherry's Industrial staff can show you the correlation between the Safety Categories and the new Performance Levels.
When designing the safety circuit, Cherry’s Industrial electrical engineers look at the machine functions and type of operator controls. Does the machine operate automatically, remotely or with press and maintain push buttons? Our circuits then can include, safety controllers, safety relays, remote e-stops, two-hand no-tie-down buttons, all designed to attain PLd safety standard. Safety isn't just electrical! Cherry's Industrial also builds all of their hydraulic circuits with safety in mind. They look at the hydraulic operations of the system, and add safety rated electrical components to minimize any potential hazards.
Under the European Directive, the responsibility of safety rests on the OEM while in the US ANSI standards assigns the responsibility of safety on the equipment purchaser. With so many regulation and guidelines in the industry, it is important to know that the Cherry’s Industrial Equipment staff has been trained and educated in current standards and guidelines, and will discuss their importance with our customers. It starts with our electrical panel which are all UL certified, UL508a with posted SCCR labels. Components are UL C and UL USA listed, as well as IEC. With the addition of perimeter guards and safety devices our machines achieve a Performance Rating of PLd , but can be built to the Performance Rating of PLe upon request.
Potential Stored Energy
When the system stops, there is stored or residual energy within the hoses and cylinders. Cherry’s Industrial takes this stored energy into consideration when designing their machines. With the use of counter balance valves, PO check valves or other locking devices, they make sure to add safety points in the system. Cherry’s Industrial has designed machines for the strictest of safety standards, including zero energy safety measures. The safety gate for these systems will not open until there is zero energy throughout the entire system.
From the color, to the mesh pattern, height and floor fixed, there are a wide variety of options in safety guarding. Based on the customer’s space requirements, how the machine operates, and what controls were chosen, Cherry’s Industrial can recommend hard guards, high style guards, modular guarding, or systems with gates with non-contact safety latches built in. Guarding protects by barring access to haards from over, under, around, and throught reaches.
Safety devices are typical chosen in conjunction with the safety guarding. With guarding protecting the sides and rear of the machine, the customer still has the loading / unloading area to protect. Light curtains, safety scanners, and safety mats are some of the options. Where hard guarding is not a viable means of protection, safety scanners and/or two-hand no-tie-down operation controls paired with a safety controller can be used. Other criteria to be considered are the E-Stops and their locations, as well as operator training for safe and efficient use of equipment. The manuals provide standard operating procedures, and the safety labeling of the machine is exhibited on a drawing for reference.