LEFOO LFS-03 Miniature Positive and Negative Pressure Switch

LEFOO LFS-03 original product photo — LEFOO LFS-03 · Manufacturer image and specification

LEFOO LFS-03 is a miniature positive/negative pressure switch. This model must be matched to the intended pressure range, mounting arrangement, contacts and complete maker option code.

LFS-03Pressure SwitchesOEM-defined configuration

Model Identification & Key Specifications

ManufacturerLEFOO

ModelLFS-03

Device functionMiniature positive/negative pressure switch

Manufacturer pressure envelope−15…800 mbar option range; 2,500 mbar maximum pressure

Electrical and connection250 mA at 250 VAC, NO/NC variant

Media / installationConfirm original OEM drawing

Approval scopeExact order-code documents required

Technical referenceOriginal model page and downloads

Engineering context: Switching setpoint, proof pressure, burst pressure and contact duty are different parameters. Do not substitute one family’s maximum for another variant’s rating.

Manufacturer-Specified Information

The original LEFOO datasheet explicitly states that tab-terminal attachment does not provide a completely air-tight body seal. Do not use the ordinary LFS-03 to maintain static vacuum where leakage is unacceptable. A special additional-spring version is available on request; verify the precise configuration with LEFOO before using it for negative-pressure retention. Low switching hysteresis is not proof of zero leakage or a sealed vacuum interface.

The original ordering guide illustrates LFS-03 0 0 0 W10 – V90 , where the pressure-setting suffix V refers to vacuum and P to positive pressure; W10 indicates a 10-inch lead option. Treat this as a manufacturer example, not a guaranteed universal stocked order code. Confirm the desired port, contact material, wiring and calibration.

Engineering Analysis and Correct Model Selection

The standard LFS-03 contact enclosure around electrical terminals is not fully airtight: do not assume it retains STATIC vacuum. Confirm the OEM airtight specialty option for pressure hold tests, and do not connect a motor directly to a 250 mA signal contact.

The mounting position, pressure pickup tubing, connection tightness and whether the actuator is momentary or maintained determine system behavior. Keep the original fail-safe circuit and examine how a switch resets or latches after power or pressure loss.

Installation & Compatibility Checks

Pressure / air tubing

Verify actual pressure direction and the integrity of hose and threaded joints; absolute, vacuum and differential ratings are not interchangeable.

Electrical switching

Check NO/NC, current, voltage and motor-start load. Low-current signal contacts must drive suitable control circuits rather than unverified loads.

Ingress and mechanical configuration

Check enclosure, wire/cable termination, process medium, ambient temperature and any assembly-specific sealing limitations.

Certificate scope

Verify the exact model suffix and the scope of any manufacturer-listed CE, UL or TÜV documentation.

Related Product Profiles

LEFOO LFS-02 · LEFOO LFS-01 · LEFOO manufacturer

Official Manufacturer Documentation

LEFOO LFS-03 model source

AirAlign independent technical reference; exact original manufacturer photo and variant-specific certification still require verification.

LFS-03 — miniature bipolar pressure contact

LFS-03 has a miniature positive/negative pressure-switch format; setpoint sign, make/break behavior and mechanical port arrangement must be confirmed for the exact component. On a PCB product, the electrical terminals may be suitable for a low-power signal, not a motor contactor coil without interface protection. Temperature, media compatibility and pressure cycling are relevant to reliability. This is not a full process pressure transmitter.