LEFOO LF5D Refrigeration Oil Differential Pressure Protection Switch
OEM-specified LEFOO LF5D refrigeration oil differential protection for refrigeration oil / approved gas applications. Selection must match the exact version, operating conditions and signal output.
Model Identification & Specifications
Original Manufacturer Technical Information
Measures DIFFERENCE between refrigeration compressor oil-pump discharge and compressor suction, rather than one simple high-side pressure. Insufficient lubrication differential trips compressor protection. OEM lists R22/R134a/R404A/gas use, SPDT, 240VAC full-load 8A / locked-rotor 48A or 120VAC FL16A/LR72A; ambient −20…65°C, medium −40…120°C, maximum fitting torque 2 N·m. Verify lubrication circuit and refrigerant/oil compatibility before treating as an ordinary pressure cutout.
Confirm pressure control versus safety-cutout role, manual reset versus automatic reset, rated pressure/temperature and actual refrigerant or steam medium. Select the correct process port, contacts, mounting enclosure and electrical locked-rotor rating for the compressor or pump. Confirm the correct order code, available model-specific imagery and relevant manufacturer compliance documents. Check manufacturer current order-code evidence before field installation.
Engineering Selection & Practical Interpretation
This is oil-differential safety protection rather than ordinary suction or discharge overpressure control. A trip indicates inadequate lubricant pressure relative to suction, so use it in the original compressor-protection circuit and verify the specific refrigerant and lubricating oil compatibility.
Before using the switch as a protective device, verify how it responds at trip, reset and loss of supply, and whether a separate calibrated monitor is required. The contact wiring, allowable media and operating temperature must correspond to the original controller design. Select a documented variant instead of assuming that similarly named housings are interchangeable.
Installation and Integration
Differentiate threshold switching from continuous measurement. Confirm adjustment range, hysteresis, measurement reference and sample setup for the operating medium.
NO/NC/SPDT contact type and current are configuration-specific. Low-current reed or signal contacts require suitable control electronics rather than direct motor wiring.
Check approved media, temperature, fitting, mounting orientation, protection against surges and ingress performance at the supplied cable termination.
Conformity needs the exact serial/part option and certificate scope. A product-family marketing statement is not evidence that another configuration is explosion-protected.
Related Product Models
Related LEFOO model #4505 · Related LEFOO model #4507 · LEFOO manufacturer profile
Official Technical Resources
LF5D — refrigeration oil differential safety
LF5D is an oil-differential-pressure protection switch for refrigeration compressors, not an ordinary air duct DP sensor. The relevant condition is net lubrication pressure under actual operating speed and temperature, and the selected delay/trip behavior must be consistent with compressor manufacturer requirements. Compare oil pressure, suction/crankcase reference and switch differential using the correct ports. Safety restart and reset provisions should be verified for the installed compressor system.