March 2017 Newsletter

Do you experience multiple or lengthy equipment downtime events when your industrial control systems fail?   Maybe you have seemingly simple issues that keep your machinery down for days.  Or you have the same issue over and over again without final resolution.  If this sounds like your operation, please read on!  This article will provide some best practice information to help reduce your downtime because of control system failure.

Use Qualified Personnel There are two main reasons for using experienced personnel – safety and productivity.  Controls system troubleshooting and repair requires an advanced skilled set to help prevent injury (including shock and arc-flash burns) and further failure.  When troubleshooting control systems, unqualified personnel will make frequent and costly mistakes including those that follow.  They will replace failed items with the wrong item.  For example, they might replace a 2-amp motor overload with a 5-amp one, thus eliminating any motor overload protection.  They might attempt to replace sensitive electronic components while they are still powered, many times resulting in further damage.  Or they will disconnect wires and then re-connect them on a terminal of a much higher voltage, resulting in further damage.  If you have complex control systems, either hire a seasoned troubleshooter or subcontract the repair process. And remember that continuing education is required as the field of industrial controls is constantly changing. Quickly Address Impending Failure Impending failure maybe water leaking into a control enclosure from the roof during a storm or snow melt.  It does not take very much contaminated water to ruin an expensive control component and shut-down your machinery.  A broken or separated conduit will eventually result in damaged, severed or short-circuited wires.  Shorted wires can then destroy power supplies and other control components.  A broken enclosure door can allow conductive dust from the process to infiltrate electronic circuit boards.  If you have electronic control devices that are held together by duct tape or wire ties, make plans to replace these items soon.  Keep Archives and Documentation Up-to-date  Memory failure on programmable industrial controls happens to most operations at some point in time.  A good plan can minimize the downtime required to restore the system to operation.  It may result because of a combination of a power-flicker and a dead battery used for memory back-up, a controller hardware failure, or an operator error.  So be persistent at uploading current programs to a flash drive and printing program hardcopies for future use.  Move the program files from the flash drive to a server that is routinely backed up.  A hardcopy of the program can be used when the flash drive is lost or destroyed, and the only way to recover is to manually re-enter the program.  Routinely check devices that have a battery backup.  Many of these devices have a warning indicator when the battery is low on power. These easy preventative tasks can be the difference between hours of downtime verses days of downtime. A Good Preventative Maintenance Program.  Extreme temperatures must be avoided inside electrical enclosures with electronic controls.  Device temperature ratings range from around 105 degrees F to about 140 degrees F.  But it is very common for control enclosures to have a mixture of controls with different temperature ratings.  Temperature raise inside enclosures is dependent on the ambient outside conditions and the size and number of the heat generating devices inside the enclosure.  At least once per year check ventilation fans, filters, A/C units, and heat exchangers for proper operation.  Perform these preventative measures about two months prior to the heat of summer.  Another preventative tool is thermal imaging.  It is a great tool to determine poor electrical connections, which left go can result in burnt-off wires.