Murphy LM500 User Manual

Section 15 00-02-0729
02-11-11 - 1 -
General Information
Description
The Murphy LM500 model maintains the crankcase oil level of an engine, pump or
compressor. Adjusted to the correct running-oil-level, the LM500 will replenish oil as it is used.
The low-level switch will alarm and/or shutdown the equipment if the supply oil is lost and the
equipment continues to use oil. The LM500-TF model includes a test feature that confirms both
the float and switch are operating correctly with a single press of the test button.
Dimensions
Pipe Mount Universal Mount

Murphy LM500 Specifications

Connections

Crankcase balance vent connection	1/2 NPTF (top)
Inlet connection	2 x 3/4 NPTF (side)
Conduit connection	1/2 inch conduit (female, top)

Switch Specifications

Snap-switch SPDT rating (AC)	10 A, 125 VAC
Snap-switch SPDT rating (DC)	0.5 A, 125 VDC, 10 A, 30 VDC

Pressure and Temperature

Maximum inlet pressure	9.50 psi/25 ft. oil (head pressure)
Maximum differential pressure	2 in (51mm) between running and stopped
Maximum ambient temperature	250°F (121°C)

Physical Characteristics

Wire leads length	14 in +/- 2 in (355 mm)
Case material	Die cast aluminum
Lens material	Clear “Frog Eye” non-staining, high impact, high temperature nylon