DGA-700 — Compact Multi-Gas On-line DGA Monitor
Hydrogen (H2), carbon monoxide (CO) and moisture-in-oil in one lightweight 10 kg unit — with acetylene (C2H2) optional. Photoacoustic spectroscopy (PAS) delivers fast, stable, maintenance-free gas-in-oil measurement at the transformer oil valve.
Product Overview
The DGA-700 is a compact on-line Dissolved Gas Analysis (DGA) monitor that continuously measures hydrogen (H2), carbon monoxide (CO) and moisture-in-oil, with acetylene (C2H2) available as an option. Built on Photoacoustic Spectroscopy (PAS), the DGA-700 delivers fast, stable and maintenance-friendly gas-in-oil measurement in a lightweight 10 kg package that mounts directly at the transformer oil valve.
Designed for power utilities, industrial plants and renewable substations, the DGA-700 suits both new installations and retrofits. Its 10-minute minimum measurement cycle provides timely early-warning data for incipient transformer faults, while its wide operating temperature range and IP55 enclosure make it reliable in outdoor substation environments. Multiple communication interfaces (RS-485, RJ45, fibre) and protocols (IEC 61850, Modbus, TCP/IP) allow direct integration into existing SCADA / monitoring platforms.
Key Features
Compact 10 kg Valve-Mount
260 × 260 × 300 mm and under 10 kg — mounts directly at the transformer oil valve or on a wall bracket. One-person installation, no transformer de-energization required.
Multi-Gas in One Unit
H2, CO and moisture-in-oil measured simultaneously; acetylene (C2H2) available as an order-time option for arcing detection.
Fast 10-Minute Cycle
Measurement cycle from 10 minutes (auto / menu / manual control) — timely detection of fast-developing faults without waiting for daily batch results.
Substation-Rated
−40 °C to +55 °C operating range, IP55 enclosure, ≤5000 m altitude rating and overvoltage category IV — built for outdoor substation duty.
Open Integration
RS-485, RJ45 and fibre interfaces with IEC 61850, Modbus and TCP/IP protocols — direct connection to SCADA, EMS and asset-monitoring platforms.
Low Power & Zero Consumables
Under 200 W power draw and no carrier gas, columns or routine consumables — low total cost of ownership over the service life.
Measurement Specifications
| Detection Parameter | Detection Range (µL/L) | Measurement Error Limit |
|---|---|---|
| Hydrogen — H2 | 0 – 2000 | ±3 µL/L or ±30% |
| Acetylene — C2H2 (optional) | 0 – 2000 | ±1 µL/L or ±30% |
| Carbon Monoxide — CO | 0 – 3000 | ±30 µL/L or ±30% |
| Moisture in Oil — H2O | 0 – 100 | ±3 µL/L or ±10% |
Notes: 1) Gas concentrations in oil (µL/L). 2) Error expressed as a percentage or absolute value (µL/L), whichever is greater. C2H2 measurement is optional and configured at order.
Operating Specifications
| Power supply | 220 V AC ±10%, 50 Hz | Power consumption | <200 W |
| Weight | <10 kg | Dimensions (H×W×D) | 260 × 260 × 300 mm |
| Ambient temperature | −40 °C ~ +55 °C | Ambient humidity | 10 ~ 95% |
| Measurement cycle | Min 10 min, max 24 h | Control mode | Auto / menu / manual |
| Communication | RJ45, fibre optic, RS-485 | Protocols | IEC 61850, TCP/IP, Modbus |
| Altitude | ≤5000 m | Overvoltage category | IV |
| IP rating | IP55 | Insulation of external circuits | ≥100 MΩ |
Configurations & Ordering
Match the DGA-700 to your monitoring requirement and budget. From a compact standard system to a sensing-core module for system integrators.
DGA-700-S
- H2 + CO + moisture-in-oil
- Fully assembled, factory-tested and calibrated
- Valve-mount / bracket kit included
- Comprehensive warranty
DGA-700-C
- H2 + C2H2 + CO + moisture
- C2H2 arcing-gas detection enabled
- Fully assembled, factory-tested and calibrated
- Comprehensive warranty
DGA-700-OEM
- Sensing core for system integrators
- Enclosure drawings + assembly guidelines
- Private-label ready
- Factory test report per module
Outline Dimensions
Overall dimensions 260 (H) × 260 (W) × 300 (D) mm. Mounting by valve-mount adapter or wall bracket; oil sample via the transformer sampling valve. Detailed installation drawings are supplied with the product manual.
Applications
Power Utilities
Distribution and transmission substations — from 110 kV upward.
Industrial & Commercial
Steel, petrochemical, cement and data-center main transformers.
Renewables
Wind, solar and hydro station transformers, including remote sites.
Fleet Monitoring
Cost-effective multi-gas coverage for large transformer fleets via IEC 61850 / Modbus.
Why choose the DGA-700?
Most faults begin with rising hydrogen; many escalate with CO (paper degradation) and moisture (insulation health). The DGA-700 puts these three core indicators — plus optional acetylene for arcing — in a compact unit that costs far less than a full 9-gas analyzer and installs in under an hour. For distribution and industrial fleets that need more than single-gas trending but don’t require laboratory-grade gas speciation, the DGA-700 is the balanced choice. When full 9-gas analysis is required, upgrade to the DGA-900 on critical assets.
Explore DGA Technology & Products
PAS DGA — a brand of VA Technology Co., Ltd. Product photographs and detailed specifications available on request. Email inquiry@pasdga.com. Specifications subject to change without notice.
How to install and start the DGA-700
- Step 1: Valve-mount — fix the compact 10 kg unit directly at the transformer oil valve; no carrier gas is needed.
- Step 2: Connect sample and return lines — oil flows through the measurement loop and back to the transformer.
- Step 3: Power and configure — set the output protocol (MODBUS RTU or IEC 61850) for the SCADA host.
- Step 4: Set the interval — choose a measurement cycle from 10 minutes up to 24 hours.
- Step 5: Start measurement — verify the H₂, CO and moisture readings (C₂H₂ when the option is fitted).
FAQ
Q: What gases does a DGA monitor detect?
A: The DGA-900 detects 9 fault gases plus moisture: hydrogen (H₂), carbon monoxide (CO), carbon dioxide (CO₂), methane (CH₄), ethane (C₂H₆), ethylene (C₂H₄), acetylene (C₂H₂), oxygen (O₂), nitrogen (N₂), and moisture (H₂O). The DGA-200/300/500 hydrogen sensors detect H₂ down to 1–2 ppm.
Q: What communication protocols are supported?
A: MODBUS RTU (RS-485) digital output and 4–20 mA analog output, with programmable dry-contact relay alarms. Higher-level protocol options (for example IEC 61850) differ by model — see the product page or datasheet for the exact interface set supplied.