15700836 – Murphy Lube Level Maintainer – LM500-TF

Murphy Level Maintainer


The LM500 maintains oil level on any size engine. Italso supports installations that require a three-wire,snap-action switch. The form C (three-wire) contactallows a controller/annunciator to bewired as a closed loop system, resulting in a reliable fault-sensitive circuit. Refer to LM500 Series Flow Rate Chart for applicationdata.The Murphy LM500-TF OilLevelMaintainer includesa test feature that confirms both the float and switchare operating correctlywith a single press of the testbutton. The LM500 series maintains the crankcase oil level of anengine, pump or compressor. Adjusted tothe correct running oil level, it will replenish oil as it isused. The low-level switch will alarm and/or shut-downthe equipment, if supply oil is lost and theequipmentcontinues to use oil. As crankcase oil level drops, the LM500 float alsodrops and opensthe Thumb-Valve™. This allows oil toflow from the supply tank through the LM500 and intothe crankcase. When proper level is achieved in thecrankcase, the LM500 float rises causing theThumbValve to close off further oil flow.The simple and uniqueThumb-Valve is non-cloggingand provides a positive, leak-free seal.If the clean oil supply is depleted and oil levelcontinues to fall, the low-level switch will operate analarm or equipment shutdown.

This product may vary on delivery times, as factories do not guarantee production due to lack of raw materials.



  • Crankcase Balance Vent Connection: 1/2 NPTF (top)
  • Inlet Connection: 1/2 NPTF removable screen (side)
  • Outlet Connection:
    • 2 x 3/4 NPTF (side)
    • 1 x 3/4 NPTF (bottom)
  • Thumb-Valve Material: Viton
  • Span-switch: SPDT rating 10 A, 125 VAC; 0.5 A, 125 VDC; 10A, 30 VDC
  • Wire leads: 18 AWG x 14 in. +- 2 in. (355 mm) length
  • Condution Connection: 1/2 inch conduit (female, top)
  • Case: Die cast aluminum
  • Lens: Clear Frog Eye non-staining, high-impact, high
  • Temperature polycarbonate; UV and heat stabilized
  • Dial: High visibility white background with solid green band for normal level indication
  • Maximum Inlet Pressure: 9.50 psi/25 ft. oil (head pressure)
  • Maximum Case Pressure: 15 psi (103 kPa)
  • Maximum Differential: 2 in. (51 mm) between running and stopped
  • Maximum Ambient Temperature: 250°F (121° C)
  • Float: 304 Stainless Steel
  • Flow Rates: Refer to LM500 Series Flow Rates chart for application data
  • Dimension: Overall 6-9/16 in. (H) x 6-3/16 in. (W) x 3-1/2 in. (D)
  • LM500/LM500-TF Shipping Dimensions: 9.5 (W) x 7.5 (D) x 11 in (H) (241.3 (W) x 190 (D) x 279.4 mm (H)
  • LM/LM500-TF Shipping Weight: 3 lbs 13.44 oz (1.74 kg)



LM500 Series Flow Rates


Mounting Brackets with Hardware

In addition to the direct mounting option, Enovation Controls offers two mounting brackets for the LM500. The pipe bracket fits a 7/8 in. (22 mm) diameter pipe (see typical installation).TheUniversal Flange Kitallows various mounting methods.

Typical Installations


How to order

In the web-shop is present standard version for remaining below parts are needed a separately quotation.


Part Number Description Note
15000954 Vent Fittings Kit one tubing vent, one 1/4 x 1/2 NPT connector
15000355 Hose Kit one – 1/2 in. (13 mm) I.D. x 3 ft. (914 mm) hose
one – 1 in. (25 mm) I.D. x 3 ft. (914 mm) hose
two – 1/2 in. (13 mm) worm gear clamp
two – 1 in. (25 mm) worm gear clamp
two – 1/2 NPT x 1/2 in. (13 mm) barbed fitting
two – 3/4 NPT x 1 in. (25 mm barbed fitting
89080801 1/2 NPT x 1/2 in. Hose Barbed Fitting
89081001 3/4 NPT x 1 in. Hose Barbed Fitting
15000519 Pipe Bracked Kit
15000519 Universal Flange Kit
15000532 Bubble Lens Kit
15000943 Fittings Kit one tubing vent; one hose barb, 1/2 NPT to 1/2 Hose; one hose barb, 1″ ID hose 3/4 NPT; one connector, 1/4 x 1/2 NPT

Informazioni aggiuntive

Peso 1,74 kg



15700836, LM500-TF