Description
ALSTOM MVAX91W1DD0754A
Technical Specifications
- Product type: Voltage supervision relay
- Monitoring voltage range: Custom AC/DC range
- Relay output: Multi potential free contacts
- Contact rating: 250V AC, 5A
- Operating delay: Adjustable delay time
- Operating temperature: -20 °C to +60 °C
- Storage temperature: -40 °C to +85 °C
- Humidity: 5% to 95%, non-condensing
- Protection: IP20
- Mounting: DIN rail / panel mount
- Input: Voltage measurement input terminals
Functional Features
- Overvoltage and undervoltage continuous monitoring
- Adjustable pickup threshold and time delay
- Voltage loss detection function
- Multi-channel potential free relay output
- Front panel LED for voltage and alarm status
- Anti-interference circuit for substation environment
- Adjustable hysteresis to prevent chattering
- Long mechanical operation life
- Suitable for DC control power monitoring
- Compact modular structure
Application Scenarios
- Substation DC control power supervision
- Generator auxiliary power supply monitoring
- Transformer control cabinet voltage alarm
- Switchgear AC auxiliary power monitoring
- Power plant UPS output voltage monitoring
Materials and Construction
- Housing: Flame retardant plastic
- PCB: FR4 board with conformal coating
- Relay: Electromagnetic relay
- Terminals: Screw copper terminals
- Voltage divider: Precision resistance network
- LED: Status indicator
Structural Features
- Slim rectangular DIN rail housing
- Front panel LED indicators
- Top and bottom screw terminal blocks
- Internal voltage sampling circuit and relay assembly
- Rear DIN rail snap clip
- No built-in cooling fan
Working Principle Input voltage passes precision voltage divider to sampling circuit. The internal circuit compares measured voltage with preset overvoltage and undervoltage threshold. When voltage exceeds upper limit or falls below lower limit, relay actuates after preset delay time. Hysteresis setting prevents relay frequent switching caused by small voltage fluctuation. LEDs display normal or alarm state.
Installation Requirements
- Mount inside substation control cabinet on DIN rail
- Connect voltage sampling cable to monitored power circuit
- Set threshold and delay parameters after power on
- Ambient temperature -20 °C to +60 °C
- Reliable cabinet grounding
- Test alarm function by applying variable test voltage
- Separate sampling wiring from high current power cable
Precautions
- Confirm input voltage range before power connection
- Do not exceed maximum rated input voltage
- Check contact condition during periodic inspection
- Prevent condensation inside cabinet
- Store spare relay in dry shockproof packaging
- Adjust hysteresis value to avoid relay chatter
