Diagnostic info gone awry?

Feedback to print and online articles on diagnostic information, intrinsically safe operations, and more.

07/01/2009


Re: “Commentary: You can lead a horse to automation…,” www.controleng.com 05/06/2009

It appears that one problem may be that the device diagnostics information often goes to the wrong person/workstation. If the device diagnostics is sent to a separate maintenance station it may not be seen, because maintenance personal are out in the field most of the time, not in front of a computer. So where could diagnostics be sent then? Who sits in front of a computer all day? The operators. By routing device diagnostics to the operators, they will be seen. But operators cannot fix devices, so what now? And what about alarm flooding? Only critical alerts (that affect the process) shall be routed to operators. See this YouTube video to learn how: Smart Integrated Diagnostics from Operator Console. — Jonas Berge

Forgotten needs?

Re: “Intrinsically safe or Explosion Proof,” Control Engineering North America edition, October 2008

As a regular user of both IS and EXD equipment for automotive spray applications (Class 1 Div. 1), it was nice to see an article about our forgotten needs. I would like to point out another important difference between IS and EXD other than costs. Maintenance. EXD enclosures maintain their integrity by using lots and lots of bolts around the perimeter with torque specs. This leads to increased labor time to service equipment, leading to longer production downtimes when there are failures. Furthermore, many times the bolts are not all secured properly after a service, thereby making the enclosure no longer safe. I have actually seen bolt heads glued onto enclosures to the guys would not have to work as hard. Scary as it may seem, it happens. With IS systems, this risk is eliminated and is one more reason to use them.

I am curious about the battery operated devices mentioned in the article. I hope they are certified for use in the environment they are putting them in. As you mentioned in the article, capacitance is a major factor in device selection. Just because a battery doesn’t create a spark when you change it out, does not mean the unit has not built up a charge that could create a spark. It is important to note that both the intrinsic barrier and the device connected to it need to be third party listed for use in the environment, with some exceptions for simple devices.

One more thing to mention. Purging and pressurization (NFPA 496) is another way in which motors can be deployed in hazardous areas. Here at FANUC Robotics America our paint robots are purged with fresh air and maintained with a positive pressure inside. This allows the use of regular servo motors in hazardous areas.

Thanks for the well done article. I am always on the lookout for ways to safely implement new controls technology in hazardous locations. — Matthew R. Carter, Senior Engineer - Controls Hardware, Paintshop Automation, FANUC Robotics America

How to kill innovation

Re: “NEMA environmental design initiative introduced in Congress,” Control Engineering News, www.controleng.com, 05/20/2009

This is a great idea. The paperwork alone should be enough to greatly reduce the number of upstarts in the market. It is only by efforts like these that we can kill innovation in the USA and protect the big companies. — M. Simon