Power partners

In the 25 years that Jeff Perry has been responsible for electrical test safety at Hammond Power Solutions (HPS), the company has never had an accident related to electrical testing, and Perry wants to keep it that way.

 The manufacturing engineer is responsible for the safety of the processes and equipment at Guelph, Ont.-based HPS — the transformer division of Hammond Manufacturing, which it split from in 2001 to become its own company. HPS designs and manufactures high-quality custom electrical dry-type transformers, as well as related engineered magnetic devices at the facility.

The transformers must be tested before they are shipped to the customer, which is why Hammond has test stations throughout its 110,000-sq.-ft. Guelph facility. Test voltages of up to 250,000 volts are used to ensure the integrity of HPS transformers.
During the testing of transformers, the company is required to ensure the safety of the operators in and around the test cells. Safety, in fact, has always been a priority at Hammond. That’s why when Steve Bellamy of Bellamy Electric approached Perry about upgrading the safety system in the testing of transformers to Omron’s G9SP software-based safety controller, Perry didn’t take the decision lightly.

“We looked at a number of devices, [looking at] the breadth of products that was offered, the ability for them to be easily configured and fit into our application, and the reputation of the product itself,” explains Perry.

After careful consideration, he decided that Omron’s G9SP was the best way for HPS to “achieve the highest level of safety” for its employees.

“High voltage is a dangerous product to work with, and we wanted to make sure that we provided safety at a level that was acceptable for our company,” says Perry. “We place high values on employees and their health and safety, and we wanted to make sure that was achieved, and [this] product did that.”

About the G9SP
Omron Industrial Automation’s G9SP Programmable Safety Controller is a software-based, standalone controller that can be quickly programmed to satisfy the complex safety control needs of small and mid-sized machines. And because it isn’t a hardwired system, user’s benefit from flexibility — the ability to reconfigure the unit when new safety features are added to their setup.

With the Omron Configuration Tool — part of the G9SP package — all aspects of input and output to the unit can be defined, simulated, tested and validated with a graphical user interface. The simulation tool allows users to test and correct settings before the system goes live. On-screen text and icon-driven menus guide the user through all aspects of setup. Clear alerts and system status give the operator an instant overview at every stage of operation. Unlike hardwired safety relays, the Omron G9SP can be reconfigured for multiple purposes, with direct connection to non-contact switches or safety mats. For example, when connected to an Omron pressure safety mat, the G9SP can sense that the mat has been activated, and can be programmed to sound an alert or shut down any dangerous part of a machine, keeping personnel safe. Meanwhile, the G9SP delivers clear diagnostics and monitoring via Ethernet or Serial connection.

The G9SP also includes a memory cassette, which means that systems designers only need to program the unit once, and use the memory cassette to install settings into each identical system. This is also useful if there is a power surge that disables the unit. The operator just puts the existing memory cassette into the new unit, and can upload the program without the need for a computer or programming software.

“The software itself is very intuitive,” says Chris Parks, an account manager with Omron Industrial Automation. “It’s a software program that you can learn inside a half an hour and be very confident in programming.”

The system is more than just a safety controller. It has diagnostic abilities, too. Online diagnosis is meant to reduce debug time to a minimum during implementation in the machine control system. And when the G9SP is up and running, it can tell the operator the state of an interlock switch — if it is damaged or if a panel door is open. All the operator needs to do is look at the screen to see where the problem is.

G9SP at HPS
Previously, the company used a simple monitored relay and switch safety interlock system. When operators tested the transformers, it was a manual procedure. As Perry explains it, the operator recorded the data onto a sheet of paper. They then took that data after the test was done to a computer and entered that information into a test database.

This approach was time consuming and increased the potential for errors, explains Perry.

“We were generally running up to four decimal points of accuracy, so sometimes there were keystroke errors and recording errors.”

With the installation of two new R&D and large power transformer test stations, a new design for a safety interlock system using Omron’s G9SP was implemented. The safety interlock system is interfaced with National Instruments’ LabVIEW software — a development environment for engineers and scientists creating test, measurement and control applications. The test is selected on a computer, applied in a controlled, consistent manner, and the data is downloaded automatically at the completion of the test into the test database. The operator has monitoring capabilities so that they can control or be aware of what’s going on. It’s all done on a computer screen, rather than with analog meters and dials.

“Certainly there are some productivity advantages to having this,” Perry says, referring to the new system. “Presently [on the test stations where the G9SP isn’t installed], it takes as long to record and enter the test data as it does to do the actual test.”

One of the G9SP’s main benefits, aside from safety, of course, is its diagnostic ability, says Bellamy, who implemented the new safety interlock system at HPS.

“One of the features it does have is a test output, which it self monitors for short circuits. So it will catch problems as they happen, where as just the regular safety relay would only get it upon the next initiation of the…circuit.”

And when the G9SP detects a problem, it shuts down the circuit and kills the power so the operator can fix the issue. The operator can see on LabVIEW that the G9SP has detected an issue with the interlock and where that issue is.
Another huge benefit, he says, is its ease of use, which translates into savings.

“It’s easy to program. I would say this is a complicated interlock system here, and it took me less than an hour to program that, and it probably saved two days worth of wiring,” he explains.
In fact, the new system has reduced installation time at HPS’ Guelph facility by 20 percent, and trouble-shooting issues by 30 percent.

The future
While the system is currently installed in four electrical test stations at the plant, Perry plans to have them installed in the remaining test stations in the near future.

And, following the G9SP’s success at HPS in Guelph, the company plans to install the controller at 10 more of its facilities — three in Canada, two in the U.S., three in Mexico, one in India and one in Italy.

“All of our test facilities will be standardized on this exact platform right here, with the G9 being the safety component and the National Instruments being the controlling and recording and measuring platform,” says Perry. “The installation is much quicker; the configuration is much quicker. Those are advantages, especially going forward, when we plan to use these in all of our other facilities.”

And the company plans to use it in additional applications; not just for the safety of personnel testing transformers. The G9SP will be used in their transformer resin bake ovens to monitor damper position and flow switches to make sure that fumes are exhausting. The team also plans to install it on a new high-speed lamination cutting machine, as well as a Core Build lift/tilt table.

“We currently have a large transformer resin impregnation system under construction with a G9SP safety interlock system. We are also working on a safety system strategy utilizing the G9SP platform for operations such as material slitting, cutting and punching,” says Perry.

“I think the Hammonds have always had the best available safety system, and as we’ve upgraded [it],” explains Bellamy, “we went from just basic relays and contactors to safety relays, and now there’s a better product — the G9SP.

“They’ve taken it to the next level,” he continues. “Hammond has taken the initiative, spent the money, and made sure that the operators are safe.”

And thanks to this technology, Perry and the HPS team are able to continue to achieve their goal — to make sure that there are no accidents related to electrical testing at HPS, and that the employees remain safe.

This article originally appeared in the May 2012 issue of Manufacturing AUTOMATION.