Transformer Monitoring Systems
Thermal and loading history on transformers that have neither.
Most distribution transformers carry no monitoring at all, which means the first reliable indication of a problem is the outage. Loading and temperature are the two variables that decide how fast insulation ages, and both are measurable without opening the tank. This system reads current through Rogowski coils and temperature through thermocouples, and detects thermal faults online: overload, hot spots and insulation degradation.
Measurement covers 0 to 380 VAC and 0 to 1,000 A over 45 to 65 Hz, with an 85–265 VAC three-phase auxiliary supply. Data leaves over DNP3, Wi-Fi or Ethernet into the Shield-X asset management dashboard, which holds event history, failure prediction and fleet dashboards. The thermal model reference is the IEEE C57.91 loading guide, with IEC 60076-7 as the equivalent, so the loading and ageing conclusions come from the same guide your planning group already uses. Integration follows DNP3 and IEC 61850.
Why it matters
Distribution transformers rarely have any monitoring, so the failure is usually discovered by the customers. Thermal and loading history moves that discovery earlier.
Thermal history plus loading history is the best single predictor of remaining insulation life, and IEEE C57.91 is the reference the industry already argues from.
A fleet view converts individual readings into replacement prioritization, which is what a capital plan needs rather than a wall of live values.
Rogowski coils and thermocouples install without an internal modification to the transformer.
DNP3 and IEC 61850 integration means the data lands in the SCADA system you already run, not in a separate island.
Ratings
Voltage measurement: 0–380 VAC
Auxiliary supply: 85–265 VAC three-phase
Current: 0–1,000 A
Frequency: 45–65 Hz
Sensors: Rogowski coils and thermocouples
Detection: Online thermal fault detection — overload, hot spots, insulation degradation
Communication: DNP3, Wi-Fi, Ethernet
Platform: Shield-X asset management dashboard — event history, failure prediction, fleet dashboards
Standards
IEEE C57.91 loading guide (thermal model reference)
IEC 60076-7
DNP3 · IEC 61850 integration
Applications
Distribution transformer fleets
Critical industrial transformers
Data center and hospital service transformers
Transformer replacement prioritization programs
Questions engineers ask
What does a distribution transformer monitor actually detect?It detects thermal faults online: overload, hot spots and insulation degradation, from current measured by Rogowski coils and temperature measured by thermocouples. Because loading and temperature drive insulation ageing, that combination gives an early indication of a unit heading toward failure, together with the loading history that explains why.
Can the monitoring data be brought into an existing SCADA system?Yes. The system communicates over DNP3, Wi-Fi and Ethernet, and integration follows DNP3 and IEC 61850. The same data also feeds the Shield-X asset management dashboard, which keeps event history, failure prediction and fleet dashboards for prioritizing replacements across a population of transformers.
Technical documentation
Choose the datasheet for the required HVEX monitoring configuration: Omni Trafo or the thermal image relay system. Ratings and interfaces are specific to each configuration.
Download HVEX Omni Trafo Transformer Monitoring System datasheet (English, PDF)
Download HVEX Transformer Thermal Image Relay and Monitoring System datasheet (English, PDF)
