Description
ZIEHL MSF-220-SE
Technical Specifications
- Product type: Speed monitoring relay
- Supply voltage: AC230V
- Input signal: NPN / PNP pulse signal from speed sensor
- Measuring range: 10 rpm to 6000 rpm
- Response time: Adjustable from 0.1 s to 10 s
- Output: 2 independent relay contacts
- Contact rating: 250V AC, 3A resistive load
- Temperature operating range: -20 °C to +60 °C
- Storage temperature: -40 °C to +85 °C
- Humidity: 5% to 95%, non-condensing
- Protection class: IP20
- Mounting: DIN rail 35mm
- Enclosure material: Plastic flame retardant
Functional Features
- Overspeed and underspeed monitoring function
- Adjustable speed threshold via front potentiometer
- Adjustable delay time to avoid false alarm during startup
- Two independent relay alarm outputs
- LED indicators for power, signal input and alarm status
- Compatibility with NPN and PNP pulse sensors
- Compact DIN rail mounting structure
- Industrial anti-interference circuit design
- Continuous long-term operation capability
- Startup inhibit function to mask speed alarm during motor acceleration
Application Scenarios
- Fan motor speed protection in HVAC systems
- Conveyor belt speed loss detection
- Pump and agitator rotating speed monitoring
- Wind turbine auxiliary rotating equipment protection
- Industrial drying oven fan overspeed protection
Materials and Construction
- Housing: Flame-retardant thermoplastic plastic
- PCB: FR4 printed circuit board with conformal coating
- Terminals: Screw type copper terminals
- Relay: Electromagnetic relay with gold-plated contacts
- Potentiometer: Front panel adjustable metal potentiometer
- LED: High-brightness status indicator diodes
Structural Features
- Slim rectangular DIN rail housing
- Front panel with potentiometers and LED indicators
- Rear integrated DIN rail snap clip
- Top and bottom screw terminal blocks for wiring
- Internal isolation barrier between power circuit and signal circuit
- Fully enclosed plastic shell without cooling fan
Working Principle Speed sensor generates pulse signals proportional to rotating speed. The relay receives pulse signals and calculates real-time rotational frequency. The internal circuit compares measured speed with preset threshold values. When speed exceeds overspeed limit or drops below underspeed limit, the relay coil actuates and changes contact state. The startup delay function suppresses false alarms during motor startup phase. Front LEDs show power status, valid pulse input and alarm trigger state.
Installation Requirements
- Mount on standard 35mm DIN rail inside control cabinet
- Separate signal wiring from high-power AC cables
- Use shielded cable for sensor pulse signal
- Supply voltage strictly set to AC230V
- Operating ambient temperature kept within -20 °C to +60 °C
- Complete parameter setting of speed threshold and delay time after power on
- Cabinet grounding connection
Precautions
- Do not apply voltage exceeding rated supply voltage
- Sensor wiring polarity must be correctly connected
- Keep the cabinet dry and avoid condensation
- Verify alarm action function during regular maintenance
- Store spare units in dry and anti-static packaging
- Do not open the plastic housing during operation
