LF10 (LF10-1H, LF10-L1, LF10-4H)

The aftermarket workhorse — 20 A, one or four port, up to 200 psi

All pressure switches
Lefoo · LF10

LF10 (LF10-1H, LF10-L1, LF10-4H)

Lefoo's LF10 is the switch inside most aftermarket boxes and a large share of new OEM compressors. It replicates the Furnas 69MB and Square D 9013FHG footprints, is UL Listed and CSA Certified, and is available in low, standard and high-pressure builds.

Specifications

Action
Standard — contacts open on rising pressure
Adjustable range
25–100 psi, 35–150 psi and higher builds up to about 200 psi
Differential
20–35 psi on the 25–100 build; 30–40 psi on the 35–150 build (fixed)
Factory settings
55/80 psi (low build) · 85/115 psi · 95/125 psi (most common)
Ports
1/4 or 3/8 in. male or female NPT single port; 1/4 in. female NPT four-port manifold version
Unloader
Available with unloader valve so the compressor never starts under load
Lever / disconnect
Auto/off disconnect lever available (the L in LF10-L1)
Enclosure
NEMA 1
Temperature
-22 °F to 257 °F

Electrical

  • 20 A at 120 VAC, 12 A at 240 VAC on the standard build
  • DPST, normally closed, snap action
  • Roughly 2 HP at 120 V single-phase on the 15 A shop build — always confirm against the switch label
  • Temperature range -22 °F to 257 °F

Size against motor full-load amps with the motor amperage calculator, and check feeder sizing with the voltage drop calculator.

Adjustment

  1. Range nut for both settings; the differential is fixed on standard builds.
  2. New-in-box Lefoos are often 5–10 psi off the stated factory setting. Verify on a gauge before you leave.
Before you open the cover

Kill power at the disconnect and lock out. Bleed the tank to 0 psi. Never set cut-out above the tank data-plate MAWP. Verify your numbers first in the cut-in / cut-out calculator.

Best fit

  • Any 95/125 psi single-phase shop compressor
  • Fast same-day replacement when the OEM switch is obsolete

Watch out

  • Counterfeit and unlisted copies exist. Look for the UL/CSA marks moulded and printed, not a sticker.
  • The 20 A rating is at 120 V — at 240 V it drops to 12 A. Size against motor FLA, not the headline number.

Cross-references

  • Furnas 69MB7LY / 69JF7LY
  • Square D 9013FHG12J52
  • Condor MDR 11 (functional, metric ports)

Manufacturer documents