LEFOO LF19 Compressor and Water Pump Pressure Switch
Compressor or pump cut-in/cut-out control in the LEFOO LF19 family. The correct operating range, contact wiring and hydraulic or pneumatic installation depend on the ordered variant.
Model Identification & Key Specifications
Manufacturer Technical Data
OEM provides 1–6, 2–11 and 5–14bar operating bands with varying factory cut-in/cut-out and 1–4bar differential, NC 250VAC 16A/25A. Its maker copy mentions well pump service but current parameter matrix says media ‘Air’ and includes unloader valve: verify actual wetted-medium/water approval for the ordered suffix rather than assuming all variants are suitable for drinking-water duty. Original maker example LF19-411121-7.5-10.5bar must not be mistaken for an exhaustive SKU set.
AirAlign Engineering & Selection Analysis
The supplier’s product description suggests water-pump use while the online parameter table specifies air as the medium. That conflict should be resolved at the manufacturer-order-code level before wet service or potable-water duty is specified.
Correct system operation is determined by the restart threshold, stop threshold, motor electrical duty and the available pressure supply. An adjustment range does not imply every combination is approved: compare manufacturer-specified differential, pressure proof, operating medium and fitting. For motor-driven equipment, locked-rotor conditions, overload protection and cycling frequency are separately important even where a contact-current rating is published.
Installation, Compatibility & Protection
Specify both cut-in and cut-out conditions for the intended equipment, and verify the manufacturer’s permitted hysteresis. Do not use proof or burst pressures as running thresholds.
NO and NC contacts have different protection and restart behavior. Match the wiring schedule and motor/contactor duty, rather than relying only on voltage and ampere numbers.
Verify actual air versus water compatibility, wetted materials, connection thread standard, sealing method and temperature of the process. The manufacturer variant must support the full application.
Manufacturer certificates and conformity documents should be interpreted only for the models and revisions explicitly covered.
LF19 Pressure Setting Classes and Fluid Compatibility
The LF19 product name includes both compressors and water pumps. However, the manufacturer parameter table labels its listed medium as Air. Before using it on a water circuit—especially potable water—obtain explicit wetted-material and application suitability evidence for the actual suffix rather than inferring approval from the product-family heading.
| Operating pressure class | Factory cut-in / cut-out pair | Published differential |
|---|---|---|
| 1–6 bar | 2 / 4 bar | 1–3 bar |
| 2–11 bar | 6 / 8 bar | 1.4–3.5 bar |
| 5–14 bar | 8 / 10 bar | 1.8–4.0 bar |
The manufacturer describes normally-closed contacts and alternative 16 A/25 A at 250 VAC. Check the selected contact version and protection requirements for the intended circuit. Evidence: LEFOO LF19 operating-class table and documentation.
Related Models & AirAlign Categories
LEFOO LF18 Three-Phase Pressure Switch · LEFOO LF16 Water Pump Switch · Pressure Switches · LEFOO manufacturer profile
Official Manufacturer Sources
Original maker catalogue evidence used for the model values above. Review the latest datasheet, ordering chart and approval scope for the specific suffix.
LF19 — confirm water compatibility separately
LF19 is described for compressor and water-pump cut-in/cutout control, while some manufacturer material lists air as its primary process medium. Before using it with water, confirm approved diaphragm/seal and connection materials for the exact LF19 suffix. Record normal tank or hydropneumatic system pressure limits, switching differential and motor control arrangement. Do not assume that product-category labeling alone validates potable-water compatibility.