Technical Specifications:

• Sensor Principle: Air-pressure diaphragm actuation
• Detection Levels: 4 discrete levels (empty / 1st fill / 2nd fill / max fill)
• Pressure Range: 0 – 250 mbar (0 – 25 kPa)
• Electrical Contact Rating: 250V AC, 5A (resistive)
• Connector: 4-pin male spade connector
• Supply Voltage to Switch: 0V (passive switch — powered by control board)
• Operating Temperature: -5°C to +55°C
• Included Hose: 1.2m silicone tube, 4mm ID

Functional Features:

• 4-position water level detection for program-specific fill volumes
• Normally Open (NO) / Normally Closed (NC) contact configuration per level
• Tube disconnection detection — board registers fault if tube is blocked or detached
• Mechanical adjustment of activation pressure via internal screws

Performance Parameters:

• Actuation Pressure Tolerance: ± 8 mbar
• Contact Bounce Time: < 5ms
• Mechanical Life: ≥ 500,000 operations
• Electrical Life: ≥ 100,000 operations at rated load
• Response Time: < 150ms

Material Composition:

• Switch Body: PA66 GF30 nylon (flame-retardant, UL94 V-0)
• Diaphragm: EPDM rubber
• Electrical Contacts: Silver-nickel alloy with gold overlay
• Pressure Tube: Medical-grade silicone, translucent
• Seals: Silicone O-rings

Structural Features:

• Low-profile rectangular design for compact chassis mounting
• Side-entry pressure port with barbed hose connection
• Top-mounted 4-pin connector for easy wiring
• Internal adjustable screws (4×) for fine-tuning each level

Working Principle:
As water fills the drum, air is displaced through the silicone tube into the switch chamber. The rising air pressure pushes against the EPDM diaphragm, which sequentially actuates four internal micro-switches at preset pressure thresholds. Each switch sends a distinct signal to the control board indicating the current water level. The board uses this data to open the inlet valve, pause filling, or proceed to the next cycle stage.

Key Advantages:

• Highly accurate water level control — reduces water and energy waste
• Robust mechanical design with no electronic components to fail
• Adjustable without replacing — fine-tune for local water pressure variations
• Tube blockage detection provides diagnostic fault code

Applicable Industries:

• Washing machine manufacturing
• Appliance service and repair
• Parts supply chain

Installation Requirements:

• Connect silicone tube to drum base air port using hose clip
• Ensure tube route has no air leaks — use clips every 150mm
• Mount switch using 2× M4 screws to chassis bracket
• Wire 4-pin connector — verify pin assignment per wiring diagram

Usage Precautions:

• Purge air from tube after connection — squeeze tube to fill with water before first use
• Inspect tube annually for cracking or hardening
• If machine shows water level fault code, check tube for blockage first
• Do not submerge switch body in water — IP40 rating only