CU eOLI, contactless ultrasonic oil level indicator
The CU eOLI is a contactless ultrasonic oil level indicator for conservators and tanks of power transformers. The sensor has no moving parts in the oil, measures the level over a range up to 2000 mm with 0.5 % accuracy and sends data via 4–20 mA and Modbus RTU.
- Principle
- ultrasound, wave time of flight
- Measuring range
- CUeOLI100: 120–1000 mm; CUeOLI200: 200–2000 mm
- Accuracy / repeatability
- 0.5 % of upper range limit
- Outputs
- 4–20 mA (load up to 450 Ω); Modbus RTU; 1 programmable changeover relay
Price, availability and lead time on request. We help with analogue selection, customs clearance and delivery.
Description
Float-type level indicators have moving mechanical elements inside the conservator, and these become a source of risk. The CU eOLI has no mechanics in the oil. The sensor on the flange emits an ultrasonic pulse, receives the wave reflected from the liquid surface and calculates the distance from the time of flight. The level is measured continuously, with automatic temperature compensation.
There are two versions. The CUeOLI100 measures over a range of 120–1000 mm and is fitted to conservators up to 1000 mm in diameter, while the CUeOLI200 works over a range of 200–2000 mm on conservators up to 2000 mm. Accuracy and repeatability are 0.5 % of the upper limit. The 4–20 mA analog output allows a load up to 450 Ω, with Modbus RTU and one programmable changeover relay for alarms available in parallel. The supply is 24 V DC ±10 %, and the current consumption is below 200 mA.
The enclosure and the DN65 flange are cast from aluminum alloy, the degree of protection is IP65, and there are two M25×1.5 cable glands. The operating and storage temperature is from −25 to +70 °C. The versions are designed for indoor and outdoor installation, coastal sites and offshore. The flange is adapted to the design of the particular transformer, and the alarm setpoints are adjustable. The standard enclosure is powder-coated in RAL 7032 to corrosion class C4-M, and the offshore model is supplied unpainted with a surface treatment of class C5-M to ISO 12944. The absolute operating pressure in the conservator must be above 600 mbar. The dielectric strength between the electronic board and the analog output is 2 kV. For analog and digital lines, a shielded twisted pair of 4×1 or 6×1 mm² with a conductor cross-section up to 2.5 mm² is recommended.
The unit is fitted to a conservator with or without a rubber bag, as well as directly on the tank. For visual checking on site there is a remote eViewer dial, mounted on the transformer wall at human height. The CU eOLI is compatible with the eDevices family and third-party devices, connects to a central control unit and is part of the MeDICA diagnostic ecosystem. Continuous oil level data moves the transformer to condition-based maintenance and remote asset management. The unit is suitable for new transformers, upgrades, tropical climates and marine conditions.
Technical specifications
| Principle | ultrasound, wave time of flight |
|---|---|
| Measuring range | CUeOLI100: 120–1000 mm; CUeOLI200: 200–2000 mm |
| Accuracy / repeatability | 0.5 % of upper range limit |
| Outputs | 4–20 mA (load up to 450 Ω); Modbus RTU; 1 programmable changeover relay |
| Supply | 24 V DC ±10 %, < 200 mA |
| Operating temperature | −25…+70 °C, temperature compensation |
| Degree of protection | IP65 |
| Flange | DN65 |
| Accessory | eViewer |
Request a price and lead time
CU eOLI, contactless ultrasonic oil level indicator. We reply within one business day.
Or email sales@usk.ua or call 044 339-50-20.
Customs codes
| UKTZED (Ukraine) | 9026 10 29 00 |
|---|---|
| HS, 6 digits | 9026 10 |
| CN (EU) | 9026 10 29 |
| HTSUS (USA) | 9026 10 20 00 |
| China customs tariff | 9026 10 00 00 |
Codes are for reference: the final code is determined at declaration for the specific model.
Questions and answers
Which CU eOLI version is needed for a conservator 1000 mm in diameter?
For conservators up to 1000 mm in diameter the CUeOLI100 with a range of 120–1000 mm is used. Conservators up to 2000 mm need the CUeOLI200 with a range of 200–2000 mm.
What outputs does the level indicator have?
An analog 4–20 mA with a load up to 450 Ω, Modbus RTU and one programmable changeover relay. The supply is 24 V DC ±10 %.
Can the CU eOLI be fitted to a conservator with a rubber bag?
Yes, the unit works with conservators with or without a rubber bag, as well as directly on the tank. The operating temperature is from −25 to +70 °C.
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