LEFOO LF10-L

A mechanical tank-pressure switch for electrically driven air compressors, available with single-port (LF10-L1H) or four-port (LF10-L4H) connections. Select the port arrangement, cut-in / cut-out settings and motor electrical load together—not as interchangeable options.

Mechanical pressure switchNormally closedAir compressor1-port / 4-port

Model Identification

ManufacturerLEFOO

SeriesLF10-L

Named model variantsLF10-L1H · LF10-L4H

TechnologyPressure-actuated mechanical contact

Measurement mediumAir

Contact configurationNormally closed (NC)

Switching adjustment range3.0–12.5 kgf/cm² (OEM family range)

Factory setpoint example6.0–8.0 kgf/cm² (OEM table)

Switch differential2.0 / 2.5 / 3.0 kgf/cm² options; not continuously adjustable

Rated contacts, manufacturer table26 A at 120 VAC · 20 A at 240 VAC

Thread optionsG1/4 · G3/8 · 1/4-in or 3/8-in NPT female

Supporting optionsUnloader valve and manual ON/OFF, subject to exact order code

Document revision matters: The current LEFOO web table gives a 3.0–12.5 kgf/cm² pressure regulation range and 26 A/120 VAC contact rating. An older manufacturer catalogue lists 45–175 psi and 20 A/120 VAC. These cannot be silently combined as one universal order-code rating. Confirm the supplied LF10-L suffix and current nameplate for the target market.

Choose the Correct Variant

LF10-L1H — single port

Appropriate where the compressor pressure switch has one dedicated sensing connection and the system’s pressure gauge and safety valve are mounted elsewhere. Simpler pneumatic plumbing, but do not assume manifold accessories are included.

LF10-L4H — four-port manifold

Provides ports for plumbing connections such as gauges and valves. These are shared pressure ports—not four independently adjustable pressure contacts. Confirm the fitting, plug and valve arrangement with the supplier.

Cut-In / Cut-Out: Why the Difference Matters

On a compressor, the switch generally stops the motor at the higher cut-out pressure and reconnects it at the lower cut-in pressure. If a configuration uses 8.0 kgf/cm² cut-out and a 2.0 kgf/cm² differential, the nominal restart threshold is approximately 6.0 kgf/cm². This arithmetic illustrates the setting relationship; actual calibration and permissible adjustment are governed by the particular switch model.

A smaller pressure differential results in more frequent cycling. A larger one increases the pressure swing in the receiver. The appropriate choice depends on receiver volume, compressor capacity, duty cycle and downstream minimum delivery pressure. A mechanical switch does not replace an independent relief valve or motor overload protection.

Engineering Selection Checklist

Electrical load and starting currentThe catalogue contact rating is not a blanket approval for every compressor motor or locked-rotor event. Verify starting current, applicable AC motor duty, overload device, local wiring code and whether a contactor is required.

Unloader and restartAn optional unloader can release pressure trapped between the compressor head and check valve after stopping. Confirm tubing dimensions, check-valve orientation and unloader function to avoid hard starts.

Threads and sealingG threads and NPT threads are not interchangeable. Match female port, sealing method and tightening limits with the receiver manifold and regional plumbing components.

Safety and enclosureDo not use a contact rating as a pressure safety certification. Verify enclosure ingress requirements, working temperature, approved use location and exact CE/UL/UKCA/TÜV document scope.

LF10-L Compared with Related Models

Family	Practical distinction	When to consider
LEFOO LF10	Related compressor pressure-control family; basic LF10 and LF10A options have different contact ratings.	When LF10/LF10A order options better match the motor and pressure envelope.
LF10-L	Single/four-port selection, OEM fixed differential options.	When the receiver manifold layout and prescribed cut-in/cut-out points are the central selection constraints.
LEFOO LF15	Different adjustment envelope, contact options and enclosure specification.	When its switching range and accessories, not merely physical appearance, match the application.

Certifications and Variant Scope

The original LEFOO product page provides UL, UKCA, CE and TÜV documents for the LF10/LF10-L families. The manufacturer-hosted UL component record E228961 names LF10-L1H and LF10-L4H. A component listing and maker download do not automatically certify an assembled air compressor or every customer-selected configuration, and none of these documents is evidence of ATEX or IECEx suitability. For a regulated installation, verify the current issue, the exact delivered model suffix and equipment nameplate.

Pressure Switches · LEFOO manufacturer profile · LEFOO LF10 · LEFOO LF15 · LEFOO LF17

Official Resources

Model-specific manufacturer references and certification-scope evidence. Check publication dates and variants before using specifications for procurement or installation.