PMC-592 for Transformer Failure Investigation and Analysis
This case study discusses an application where CET’s PMC-592s are being deployed as a tool to collect data for Pad Mount Substations by the Asset Management Group of Endeavour Energy. The purpose of this application is to collect one year’s worth of 10-minute data for the study of possible correlation of electrical and environmental parameters with transformer failure.
Transformer failure can cause many problems. A simple fault at the distributing end can cause black-out to a whole area. The fault can be very dangerous because a transformer failure can cause fire and explosions. Different faults are caused by different reasons. This study could enhance the understanding of transformer failures and allow the utility to implement preventive and maintenance measures to minimize transformer failures and to extend their operational life.
Scope of Measurement
3-phase measurements are performed on an outdoor Pad Mount Substation with one incomer and four outgoing circuits. A PMC-592 is installed with one CT strip containing twelve 5A CTs to record 3-phase Voltages, per phase Current Demands and Peak Demands for the transformer’s incomer and its outgoing circuits as well as the average transformer and enclosure temperature over 10-minute intervals.
The PMC-592 is configured to record and maintain at least one year’s worth of data in its non-volatile memory for future analysis. No HMI or real-time communication is required for this long term monitoring task since no regular maintenance or data download is performed during the monitoring period unless the transformer is found to be operating abnormally. However, the time to download one full year of data logs should take no longer than 1 minute via the PMC-592’s built-in Ethernet port for rapid analysis.
The PMC-592 Multi-Circuit Power Monitor is CET’s latest offer for PDU, LVDB and Load Center applications that require multi-circuit monitoring. Housed in compact metal enclosure with standard tropicalization and extended temperature range, the PMC-592 is perfectly suited for applications that have high density metering requirements. The PMC-592 features quality construction with multifunction and high-accuracy measurements, two Mains Inputs, up to 84 Branch Circuit Inputs and an optional touch-screen HMI. The PMC-592 comes standard with two Digital Inputs for status monitoring, two Relay Outputs for control or alarming as well as two RTD Inputs for temperature measurements. The standard SOE Log records all setup changes, Setpoint alarms and DI/DO operations in 1ms resolution. With Ethernet and dual RS-485 as standard features supporting Modbus RTU/TCP, HTTP, SMTP as well as SNMP, the PMC-592 becomes a vital component of an intelligent, multi-circuit monitoring solution.
The supply of CET’s PMC-592 is under an annual contract of 500 units since the beginning of 2015. So far, over 1000 units of PMC-592 have been deployed over the last 2 years to Endeavour Energy.
1. Recording Interval: 10 minutes
2. Recording Depth: 52704
3. Recording Mode: FIFO
4. Data Recorder Parameters:
• Mains Va/Vb/Vc
• Mains Ia/Ib/Ic Demand
• Branches I01-I12 Demand
• Average Temperature for
Enclosure and Transformer
5. CT Ratio:
• Mains Current: 1500/5=300
• Branch Currents: 400/5=80