EDOC-H / eDOC-HM, online hydrogen and moisture analyzer for transformer oil (DGA), data concentrator
The eDOC is an online oil diagnostic device for power transformers that continuously measures dissolved hydrogen and, in the eDOC-HM version, also moisture. The unit also works as a data concentrator for other eDevices and sends data to SCADA via Modbus, DNP3.0 or IEC 61850.
- Models
- eDOC-H (H₂), eDOC-HM (H₂ + H₂O)
- Inputs
- 3 × 4–20 mA, Modbus RTU (concentrator of eDevices and third-party devices)
- Outputs
- 2–3 dry contacts; 2–3 × 4–20 mA; RS485; 2 × RJ45; fiber-optic; USB-A
- Protocols
- Modbus RTU, Modbus TCP/IP, DNP3.0, IEC 61850
Price, availability and lead time on request. We help with analogue selection, customs clearance and delivery.
Description
Hydrogen is formed in almost all types of transformer faults, from partial discharges to overheating and arcing, and rising moisture accelerates the aging of paper insulation. Continuous measurement of these two parameters shows an abnormal state at an early stage. The trend is used to decide whether additional oil analyses and intervention are needed.
The eDOC-H monitors hydrogen H₂, and the eDOC-HM hydrogen and moisture H₂ + H₂O. The hydrogen measurement is insensitive to the presence of other gases, and the analysis is carried out on continuously renewed oil samples. The enclosure has a display with icons for setting thresholds and functional checks on site, and drain valves for safe sampling. The unit is mounted on a plug and play basis on a tank valve with a 1.5″ NPT thread, or 1″ NPT or EN flanges to order. On the transformer side the mounting stub length is no more than 400 mm, with a minimum diameter of 1″. During oil circulation the current does not exceed 1 A, and a 4–6 A circuit breaker with a C, K or Z characteristic is fitted in the supply circuit. The dielectric strength between the contacts and earth is 2 kV for 60 s.
As a data concentrator the eDOC receives signals of other eDevices and third-party instruments through 3 inputs of 4–20 mA and Modbus RTU. The outputs are 2 or 3 dry contacts (H₂, H₂O, fault), 2 or 3 analog 4–20 mA (H₂, H₂O, temperature), RS485, two RJ45 ports, a fiber-optic interface and a USB-A for downloading data on site. The protocols are Modbus RTU, Modbus TCP/IP, DNP3.0 and IEC 61850. For remote control there is a built-in web interface designed with a cybersecurity assessment in mind.
The degree of protection is IP66/IP67, corrosion protection is C5-M, and CX to order. Vibration resistance is class 4M6 to EN 60721-3-4, and seismic resistance is to EN 60068-3-3. The operating temperature is from −40 to +80 °C, the oil temperature from −40 to +120 °C, and the oil pressure 0–10 bar. The dimensions are 162 × 255 × 355 mm, and the weight is 8.5 kg. The eDOC is fitted to power transformers at substations and power plants, in smart grid networks and at offshore sites, and in the MeDICA ecosystem it acts as the central element.
Technical specifications
| Models | eDOC-H (H₂), eDOC-HM (H₂ + H₂O) |
|---|---|
| Inputs | 3 × 4–20 mA, Modbus RTU (concentrator of eDevices and third-party devices) |
| Outputs | 2–3 dry contacts; 2–3 × 4–20 mA; RS485; 2 × RJ45; fiber-optic; USB-A |
| Protocols | Modbus RTU, Modbus TCP/IP, DNP3.0, IEC 61850 |
| Connection | 1.5″ NPT (standard); 1″ NPT, EN flanges |
| Degree of protection | IP66, IP67 |
| Corrosion protection | C5-M (CX to order) |
| Dimensions / weight | 162 × 255 × 355 mm; 8.5 kg |
| Temperature | ambient −40…+80 °C; oil −40…+120 °C; oil pressure 0–10 bar |
| Vibration / seismic | 4M6 (EN 60721-3-4); EN 60068-3-3 |
Request a price and lead time
EDOC-H / eDOC-HM, online hydrogen and moisture analyzer for transformer oil (DGA), data concentrator. We reply within one business day.
Or email sales@usk.ua or call 044 339-50-20.
Customs codes
| UKTZED (Ukraine) | 9027 10 10 00 |
|---|---|
| HS, 6 digits | 9027 10 |
| CN (EU) | 9027 10 10 |
| HTSUS (USA) | 9027 10 20 00 |
| China customs tariff | 9027 10 00 90 |
Codes are for reference: the final code is determined at declaration for the specific model.
Questions and answers
How do the eDOC-H and eDOC-HM differ?
The eDOC-H measures dissolved hydrogen H₂, and the eDOC-HM hydrogen and moisture in the oil. Both versions are mounted on a tank valve with a 1.5″ NPT thread.
How is the eDOC connected to the transformer?
Through a tank valve with a 1.5″ NPT thread, or 1″ NPT or EN flanges to order. The oil pressure at the mounting point is 0–10 bar.
Which protocols does the eDOC support for SCADA?
Modbus RTU, Modbus TCP/IP, DNP3.0 and IEC 61850. The physical interfaces are RS485, two RJ45, fiber-optic and USB-A.
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