Power supplies give advance warning of potential trouble

Paul Boughton

Demands on functionality of power supplies in modern industrial cabinets far exceeds their original function of converting mains to energy supplied at appropriate voltages. A plethora of sizes, electrical specifications, standards and features are needed depending on the actual application.
Maintenance of high quality, reliability, continuous operation and high productivity on the shop floor are paramount. This is frequently done by a combination of preventive or predictive maintenance strategies.
Power supplies are regarded as the heart of the control and production system and any failure there will be immediately reflected on to the process and resulting products. A case study at a large automotive manufacturer showed that possible causes of failure can be grouped broadly into four categories:
u Abnormality on input side, voltage drop, power shortage, and momentary power failure on the ac input side are said to be major causes in 21percent of the cases.
u 27percent is caused by an abnormality on output side, including short-circuits.
u In 23percent of the cases deterioration of the power supply may represent the end of life of the power supply used.
u The 29percent of other failures may include unidentifiable factors such as malfunction caused by possible noise or lightening surge.
Failures caused by an abnormality on input side can be solved with Omron’s S8T-DCBU-02 backup unit. In case of end of life of the power supply Omron’s S8VS family, with preventive maintenance features, offers a reliable solution.
With conventional power supplies, there have been several technologies and means used to alert an abnormality on dc voltage of the device. These technologies however have never been adequately functional to offer the end user a troubleshooting tool to help identify the cause of such failure.
The S8VM series offers an undervoltage alarm with a diagnosic function to aid on-site troubleshooting. This enables the customer to go straight to the heart of the problem, whether in the mains supply, the electrical circuit of the cabinet or the power supply itself. The result is fast remedial action with no costly delays.
In conclusion, Omron S8VM series makes the troubleshooting on the shop floor easier and the necessary remedial action can be taken quickly. Besides, the troubleshooting alarm helps the end user optimise its maintenance operation on the shop floor. Instead of performing so-called scheduled or periodical maintenance, where all power supplies used are replaced by new ones at once, it is possible to reduce the frequency of these maintenance operations or change only the power supplies with clearly identified sources of failure – improved reliability at much reduced costs!

Kiyotaka Tomioka is Product Marketing Manager Power Supplies, Omron Europe BV, Hoofddorp, The Netherlands. www.europe.omron.com

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