Troubleshooting Infrequent Alarms in a Substation

Automated Monitoring Solution from dataTaker

CAS DataLoggers recently provided the automated monitoring solution for a wood products manufacturer whose workers were occasionally experiencing ‘Under Frequency’ alarms at their electrical substation, but they couldn’t find the cause. Meanwhile these alarms were disrupting production and proving costly over time. Maintenance staff believed that they could identify the cause if they could log their power levels, but the infrequent nature of these faults meant that they would have to wade through enormous amounts of data to find the small amount that was relevant. Ideally, the customer wanted to monitor the power levels (in kW) 10 minutes before and 10 minutes after each fault, so they required an intelligent solution capable of event-based logging.

The manufacturer installed a dataTaker DT80 Intelligent Data Logger in the substation’s control cabinet which was then connected to power transmitter sensors going out to the room’s machinery. A cost effective data logger expandable to 100 channels, 200 isolated or 300 single-ended analog inputs, the dataTaker was able to log nearly any physical value. Given that the client needed to record data 10 minutes prior to and 10 minutes following an electrical fault event, users enabled the dataTaker DT80’s ‘Archive’ function. In this way, the dataTaker was setup to store 20 minutes’ worth of data in an efficient rolling buffer where old data was dropped off as new data was collected.

Whenever an alarm condition occurred (as measured by a power transmitter), the data logger continued to log for 10 minutes before archiving the 20 minutes of data in the buffer. By waiting 10 minutes, the buffer contained 10 minutes of data before the alarm and 10 minutes following the alarm. Using this method, only the data relating to each alarm was saved to memory for later retrieval and analysis, and all superfluous data was discarded.

Users quickly retrieved the data via the local area network using either a FTP client or a web browser, which also allowed for remote access to logged data, configuration and diagnostics.  They could also query the number of events through the dataTaker’s internal web server and use a USB memory stick to manually collect new data as the events occurred.

The manufacturer soon solved its ongoing alarm problems using the dataTaker for its substation monitoring solution. By logging power levels both pre- and post-event, the datalogger tracked the intermittent faults and enabled maintenance staff to pinpoint and resolve the problem, freeing up their time. Additionally, the dataTaker’s rugged design and construction provided reliable operation under rough handling and other mishap.