Bushing and problem-detection monitor: bushings, OLTC, cooling, partial discharge and multi-gas DGA on a single platform
The C50 monitors up to six transformer bushings, the on-load tap changer (OLTC), the cooling system and partial discharge, and integrates third-party multi-gas DGA and moisture analysers over a serial link. It adds these functions to the basic thermal monitoring of oil, load and ambient temperature, with hot-spot calculation and insulation ageing.
Advantages
Real-time bushing monitoring
50% of bushing failures end in fire. The C50 provides real-time bushing data in any weather condition, load and rated voltage, with the sensitivity of an offline measurement.
Two bushing measurement techniques
Sum of currents detects leakage-current imbalance between bushings; voltage reference calculates each bushing's power factor independently and is less affected by grid fluctuations.
Integrated partial discharge and dissolved gas
Measures up to 15 electrical partial-discharge channels with tap sensors, RFCTs and Rogowski coils, and integrates third-party multi-gas DGA and moisture analysers over a serial link.
OLTC and cooling diagnostics
Monitors tap position and the tap-changer motor current and voltage, and tracks fan and pump current, contactor status and oil flow for the cooling system.
Applications
- High-voltage transformers with bushings rated 69 kV and above.
- Condition-based maintenance of bushings, OLTC and cooling system.
- Consolidating third-party data — multi-gas DGA, moisture — on one platform.
- Fire prevention through early detection of bushing deterioration.
About the product
The C50 integrates into a transformer monitoring platform that consolidates bushing, temperature, OLTC, cooling and partial-discharge data in one place, along with third-party devices such as multi-gas DGA analysers. The built-in web dashboard lets users view the data from any browser, with no software installation.
Bushing monitoring combines sensors installed in each bushing's capacitance tap with a balancing unit and a summation unit: under balanced conditions the vector sum of leakage currents is zero, and a change in a bushing's capacitance or power factor produces a deviation whose magnitude indicates severity and whose vector points to the affected bushing. The unit learns normal behaviour with load, humidity and temperature.
Available accessories: BAU bushing sensors; 8, 16 and 28 kV coupling capacitors for bushings without a capacitance tap; Rogowski coils and radio-frequency current transformers; a contact wear sensor kit for the OLTC; and a switching kiosk for installations with a spare single-phase transformer.
Technical specifications
| Thermal monitoring | Top oil, ambient and load; calculated hot spot; thermal ageing |
| Bushings | Up to 6 BAU sensors; sum of currents or voltage reference; power factor and capacitance |
| Partial discharge | Up to 15 electrical channels; tap sensors, RFCTs and Rogowski coils |
| Dissolved gas and moisture | Serial integration of third-party multi-gas DGA and moisture analysers |
| OLTC | Tap position, motor current and voltage, Delta T; optional contact wear sensor |
| Cooling | Staged control; fan/pump current, contactor and oil-flow monitoring |
| Voltage control and fibre optics | Essential tap-changer voltage control; optional winding fibre-optic probe |
| Communications | DNP3, Modbus, IEC 61850; copper/fibre Ethernet, RS-232/RS-485; web dashboard |
| Power supply and mounting | 110-240 VDC or 110-250 VAC; -40°C to +70°C; DIN rail, panel or 19″ rack |
Frequently asked questions
How many bushings can the C50 monitor?
Up to six, with BAU sensors and either the sum-of-currents or voltage-reference technique.
Does it detect partial discharge?
Yes, up to 15 electrical channels with tap sensors, RFCTs and Rogowski coils.
Does it integrate dissolved-gas analysis?
Yes, via a serial link to third-party multi-gas DGA and moisture analysers.
What does it add over a basic temperature monitor?
Bushings, OLTC, partial discharge, multi-gas DGA, essential voltage control, cooling monitoring and fibre optics.
