As we know, testing is imperative to ensuring that powertrain components perform to the expectations of the end consumer. That said, this is not always a safe process.
Machines used to verify component performance are quite powerful and can present safety risks along with them. As a manager, you don’t want to see any members of your team hurt. As an operator, you want to make it home every night as healthy as you were when you left. This is why we are highlighting the most important safety functions to have built into your testing equipment.
For starters, let’s consider the different types of hazards. These include: electrical, temperature, pressure, chemical, rotating machinery, sound and crush hazards. Today, we will tackle a few of them (electrical, temperature and pressure).
Most test machines (including ATA’s Ensure™ test systems) have high-voltage electrical cabinets that are powered by 380-460VAC 3-phase power. Installing labels warning operators of the electrical hazards is only the first step. Safety functions should be designed into the test machine to protect you and your team from machine faults and potential human error.
When the machine is on, any sort of access to the electrical cabinet must be restricted. During conversations with vendors, inquire about safety functions preventing access to the electrical cabinet when the main power switch is on. Additionally, it is important to include a main disconnect switch with the ability to lock the cabinet. This will add another layer of protection, preventing your team from making a costly mistake. Make sure you have circuit breakers in place for each power device (ie. electric motors, power supplies, heaters).
On the software side, there are a couple of things you can do the protect from electrical hazards. Make sure the software is monitoring for faults on the control power supply. Secondly, like most electrical components, there is always the potential for overheating. This is why thermal overload monitoring is very important for AC motors. If the software detects either issue, you want to ensure that control power to the machine is removed.
Many test machines (like Ensure™) are equipped with air and fluid heaters, whose heating coils can reach temperatures ranging from +200°C to +400°C. The heat can be conducted to all parts of the machine, becoming a burn hazard. For cold temperature tests, parts of the machine can be found at temperatures close to -50°C during testing. Signage and fire extinguisher location awareness is extremely important, but what should your test system be doing to protect against potential temperature hazards?
Some of the more obvious physical solutions include insulating pipes to protect from hot and cold test fluids exchanging temperature with the pipes. Enclosures to protect the operator from running components under test are a must. Ensuring that the heater sheath temperature is monitored by a safety-rated device, keeping it below target temperatures is critical. Lastly, there should always be a hardware device dedicated to monitoring the flow across heating elements, to make sure that there is always some flow going through the heater.
For software, you should always have an absolute minimum/maximum limit specific to each temperature sensor. Additionally, a local minimum/maximum limit for each temperature sensor during specific test sequences should be applied. The result of either limit being exceeded should result in control power being removed from the machine. These limits are automatically set in our FloINT™ software.
Although the Queens hit song “Under Pressure” was a classic, pressure hazards are something you shouldn’t take lightly. Lubrication pump test machines can can reach fluid pressures as high as 100 Bar. If the correct safety functions are not in place, then you could be in a serious situation if a flex hose bursts, a hose clamp comes loose, a fitting leaks, a gasket fails, etc. This would result in the test fluid quickly and dangerously discharging to atmosphere.
So what should you look for to ensure your operators are safe from pressure hazards? Well for starters, always wear your PPE (ie. safety glasses) and that all operators are aware of the potential hazards and safety functions put in place. On an Ensure™ test system, you will find that while a test is running, you can not open the gull-wing doors without triggering the safety switch and ultimately removing control power from the machine. This was put into place to prevent an operator from tinkering with the machine during a test.
It is important to ensure the machine has mechanical safety pressure relief valves (fixed or adjustable). If there is a loss of control power, then you should be able to rely on vent valves to safely depressurize the system. If nothing else, there must at least be an emergency stop button integrated and easily accessible by the operator in case something goes wrong.
With software, you should always have an absolute minimum/maximum limit specific to each pressure sensor. Also, a local minimum/maximum limit for each pressure sensor during specific test sequences. The result of either limit being exceeded should result in control power being removed from the machine. Again, this functionality is included in the FloINT™ software.
Learn more about ATA™’s component test system products.