VaultSafe (VSM) — hydrogen and pressure monitor for network transformers in underground vaults
VaultSafe (VSM) is a monitor for network transformers installed in underground vaults of urban distribution networks. It continuously monitors hydrogen and pressure in the main tank, the tap changer compartment and the cable compartment, and gives the network company remote access to the condition of the transformers. Such transformers supply hospitals, commercial buildings and public transport in dense urban areas.
- Compartments monitored
- tank, tap changer compartment, cable compartment (1 or 3 ports)
- Hydrogen measuring range
- 25–100 000 ppm
- Accuracy
- ±20% or ±25 ppm
- Power supply
- 12, 24 or 48 V DC or 120–240 V AC (50–60 Hz)
Price, availability and lead time on request. We help with analogue selection, customs clearance and delivery.
Description
A failure of a network transformer in a vault can result in damage to equipment and property, a long power outage and even injury to people. The transformer has three separate compartments, any of which can become the site of a fault, and the failure most likely starts in the cable compartment. Conventional monitors check hydrogen only in the tank, while VaultSafe covers all three compartments with one sensor and reports when hydrogen in the gas space rises. Early warning of an emerging defect allows the transformer to be taken out of service and inspected before failure.
Gas adapters are fitted to the existing compartment fittings. Gas from each compartment is drawn into a common line, a pump moves the sample through a chamber with a solid-state hydrogen sensor, and the sample is then split again into three lines and returned to the gas space of the compartments. The sensor reading is calibrated to match the gas dissolved in the oil. Installation is simple, because an existing access point on the transformer is used.
The same system equalises pressure between the compartments and detects overpressure and vacuum more accurately. If any compartment loses sealing, the total pressure drops and the monitor sends a signal, which is especially important in the harsh conditions of underground vaults. Pressure control in all compartments prevents the ingress of moisture and atmospheric air. The monitor is submersible, self-calibrating and maintenance-free, and it is fixed with magnets, so it is convenient to install on transformers already in operation. A magnetic RTD sensor for temperature monitoring is available as an option.
Hydrogen measuring range 25–100 000 ppm, accuracy ±20% or ±25 ppm. Power supply 12, 24 or 48 V DC or 120–240 V AC 50–60 Hz, operating temperature from −40 to 70 °C. The monitor has Ethernet, RS-232 and RS-485 ports with Modbus and DNP protocols, four Form C relays with NO, NC and COM contacts, three configurable analogue outputs for current or voltage, and 0–20 mA or 0–5 V inputs. The housing is 187 mm wide, 296 mm high and 129 mm deep. When ordering, the version with one or three ports, the protocol and the supply voltage are selected.
Technical specifications
| Compartments monitored | tank, tap changer compartment, cable compartment (1 or 3 ports) |
|---|---|
| Hydrogen measuring range | 25–100 000 ppm |
| Accuracy | ±20% or ±25 ppm |
| Power supply | 12, 24 or 48 V DC or 120–240 V AC (50–60 Hz) |
| Operating temperature | from −40 to 70 °C |
| Communication ports | Ethernet, RS-232, RS-485 |
| Protocols | Modbus, DNP |
| Outputs | 4 Form C relays (NO, NC, COM); 3 configurable analogue outputs (current or voltage) |
| Inputs | 0–20 mA or 0–5 V |
Request a price and lead time
VaultSafe (VSM) — hydrogen and pressure monitor for network transformers in underground vaults. We reply within one business day.
Or email sales@usk.ua or call 044 339-50-20.
Questions and answers
How many transformer compartments does the VaultSafe monitor?
Three: the main tank, the tap changer compartment and the cable compartment, covered by one hydrogen sensor. When ordering, the version with 1 or 3 ports is selected.
What are the hydrogen range and accuracy?
From 25 to 100 000 ppm with an accuracy of ±20% or ±25 ppm. The sensor is solid-state, and its readings are calibrated to the gas dissolved in the oil.
What power supply and interfaces does the VaultSafe have?
Power supply 12, 24 or 48 V DC or 120–240 V AC. Ethernet, RS-232 and RS-485 ports with Modbus and DNP protocols, 4 Form C relays and 3 analogue outputs.
Similar equipment from other manufacturers
