E3 (E Series) — monitoring, cooling and OLTC control system for power transformers
E3 (E Series) is a modular hardware platform for monitoring, control and communication of power transformers. It watches bushings, windings, the OLTC, the cooling system and insulation, collects data from third-party intelligent devices and DGA analysers, and serves as the single point for alarm transmission. The platform supports condition-based maintenance, so staff fix problems instead of collecting data by hand.
- Composition
- CPU, power supply, multi-port module and up to 12 modules
- Power supply (DC)
- 48–275 V DC, 50 W
- Digital inputs
- 12 per module, isolation 2.5 kV AC for 60 s and 5 kV impulse
- Digital outputs
- 8 Form C relays per module; 6 A at 250 V AC / 30 V DC
Price, availability and lead time on request. We help with analogue selection, customs clearance and delivery.
Description
Offline transformer tests are carried out once every few years, and a failure can occur between them. Online monitoring runs continuously, at operating temperature and under network voltage. This matters most for bushings, because 50% of bushing failures can end in a fire. The E3 tracks bushing capacitance and power factor, measures partial discharge through the bushing measuring taps and separates internal signals from external interference. The bushing monitoring module and the PD monitor are supplied as separate systems or as integrated E3 modules. OLTC motor current and voltage are monitored continuously, and a separate operation counter is kept for each tap position. The system also records short-circuit currents, harmonics and geomagnetically induced currents (GIC) in the neutral.
The design is modular. A DIN rail of 35 mm carries the processor module with USB and Ethernet ports (copper and optical), a universal power supply for 48–275 V DC or AC mains, a multi-port module and up to 12 modules. The digital input module has 12 channels with individual isolation of 2.5 kV, and the output module contains eight Form C relays rated 6 A at 250 V AC. Analogue modules accept current signals, Pt100 and DC signals, and the variant with outputs adds 4–20 mA outputs. Accuracy of the analogue channels is ±0.2% of range. The multi-port module takes OLTC motor current monitoring cards, dual current and temperature inputs, an AC voltage input for active and reactive power calculation, and RS-232, RS-485 and an optical serial port. A separate module measures winding temperature directly with fibre-optic sensors.
Analytics cover a moisture model that accounts for bubble formation, a thermal model with an oil temperature forecast, calculation of time to the thermal limit and of the maximum safe load, and what-if scenarios (load for a given time, or time at a given load). The thermal model corrects the calculated hottest-spot temperature of the winding for the serviceability of the cooling. The harmonic and short-circuit counter map records the number and maximum current of faults, the accumulated current, THD and the ratio of even to odd harmonics. Multi-gas analysers and moisture sensors from third-party manufacturers are connected over a serial channel, so the data arrives in digital form without loss of accuracy.
The E3 controls more than four cooling stages, two-speed fans, parallel pumps and variable-frequency fans, and switches cooling on in advance, based on the forecast. It can be set up as the main voltage regulator of the transformer or as a backup to an existing one, which reduces the number of separate devices at the site. The modules operate at temperatures from −40 to 80 °C and humidity up to 95% without condensation. Alarms are distributed among services over several SCADA channels and by e-mail, grouped into general, main and secondary, and the data is available on built-in web pages and in the analysis software.
Technical specifications
| Composition | CPU, power supply, multi-port module and up to 12 modules |
|---|---|
| Power supply (DC) | 48–275 V DC, 50 W |
| Digital inputs | 12 per module, isolation 2.5 kV AC for 60 s and 5 kV impulse |
| Digital outputs | 8 Form C relays per module; 6 A at 250 V AC / 30 V DC |
| Analogue inputs | 2 × AC current, 2 × Pt100, 2 × DC (0–1 mA, 4–20 mA, 0–10 V) |
| Accuracy of analogue channels | ±0.2% of range |
| Operating temperature | from −40 to 80 °C |
| Humidity | up to 95% without condensation |
| Mounting | 35 mm DIN rail, removable terminal blocks |
| Communication | USB, Ethernet (copper and optical), RS-232, RS-485, optical serial port |
Request a price and lead time
E3 (E Series) — monitoring, cooling and OLTC control system for power transformers. We reply within one business day.
Or email sales@usk.ua or call 044 339-50-20.
Questions and answers
What power supply does the E3 need and in what conditions do the modules operate?
The power supply is universal, for 48–275 V DC mains drawing 50 W, or for AC mains. The modules operate at temperatures from −40 to 80 °C and humidity up to 95% without condensation.
How many modules can be installed in one E3 system?
Together with the processor module, the power supply and the multi-port module on a 35 mm DIN rail, up to 12 modules can be installed. The digital input module has 12 channels with 2.5 kV isolation, and the output module has 8 Form C relays.
Can the E3 regulate transformer voltage?
Yes, the E3 can be set up as the main voltage regulator or as a backup to an existing system. Monitoring of OLTC motor current and voltage, along with an operation counter for each position, helps detect drive faults early.
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