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LM-92164N

Revised 10-03

Section 15

(00-02-0176)

Installation Instructions for Level Maintainers

Model Series LM300

LM300:

Level Maintainer only (no switches).

LM301:

Low switch contacts for low level shutdown or 

alarm. Four wires, SPDT. 

LM302:

Two switches for low and high level shutdown or alarm. Four wires,

DPST, wired N.O. in normal operating ranges.

LM303:

Two switches for low and high level shutdown or alarm. Four wires,

DPST, wired N.C. in normal operating ranges.

LM304:

Two switches. Alarm before shutdown on low level and shutdown on

low-low level. Four wires, DPST, wired N.O. in normal operating ranges.

LM305:

Two switches. Alarm before shutdown on low level and shutdown on low-

low level. Four wires, DPST, wired N.C. in normal operating ranges.

Specifications

Case/Cover:

Die cast aluminum.

Switch Housing:

Aluminum.

Approval Rating: 

LM301 thru LM305 : 

CSA certified

††

for non hazardous

locations. Enclosure Type 4 certified.

LM301-EX thru LM305-EX: 

CSA certified

††

for Class I, Groups C and D;

Class II, Groups F and G hazardous locations. Enclosure Type 4 certified.

Float:

Rigid polyurethane foam. Polyurethane coated.

Maximum Ambient Temperature: 

250°F (121°C)

Oil Inlet Connection:

Top entry 1/2-14 NPT with built-in filter screen (removable

for cleaning).

Inlet Orifices:

1/4 in. (6 mm) standard. 1/8 in. (3 mm) available.

Wire (switch models):

18 AWG x 13 in. (1.0 mm

2

x 330 mm).

Maximum Inlet Pressure (MIP):

Max. Differential:

2 in. (51 mm) between running and stationary oil level.

30 psi (207 kPa) [2.07 bar].

with 1/8 in. (3 mm) orifice.

15 ft. oil (4.6 m oil) 

with 1/4 in. (6 mm) orifice.

Maximum Case Pressure (MCP):

15 psi (103 kPa) [1.03 bar]. 

Orifice Seal

:

Buna-N Thumb-Valve™

Switch Contact:

Silver, SPDT snap acting, 10A @ 125, 250VAC; 10A @ 30VDC.

(1 only for low level; 2 only for high & low; or 2 only for low with alarm before shutdown)

Outlet Connection:

3/4-14 NPT left side, right side, and bottom.

Crankcase Balance Vent Fitting:

1/2-14 NPT.

Mounting:

Accepts Murphy pipe mounting or universal mounting brackets.

Lens:

Clear “Frog Eye” non-staining, high impact, high temperature nylon; UV

and heat stabilized.

Dial:

High visibility white background with green and white “index” lines for

normal level indication.

Test Knob:

Rotate to test switch operation. Turn clockwise for low level test

and turn counterclockwise for high level test.

Flow Rate Test:

Using SAE 30 @ 32°F (0°C).

Optional Hose Kit: 15000355

Quantity Description

1/2 in. (13 mm) I.D. x 
3 ft. (914 mm) long hose

1 in. (25 mm) I.D. x 
3 ft. (914 mm) long hose

2 1/2 

in. 

(13 mm) worm gear clamp

2 1 

in. 

(25 mm) worm gear clamp

1/2 NPT x 1/2 in. (13 mm) barbed fitting

3/4 NPT x 1 in. (25 mm) barbed fitting

††CSA certified with switch contacts rated at 10 A @ 250 VAC (standard).

**

Products covered by this bulletin comply with EMC Council directive
89/336/EEC regarding electromagnetic compatibility except as noted. 

GENERAL INFORMATION

Read the following instructions before installing

A visual inspection of this product for

damage during shipping is recommended before mounting. These installation instructions are
intended for all LM300 series models.

Patent
5493086

LM301-EX

Shown with optional hose kit fittings

WARNING

BEFORE BEGINNING INSTALLATION OF THIS MURPHY PRODUCT

Disconnect all electrical power to the machine.

Make sure the machine cannot operate during installation.

Follow all safety warnings of the machine manufacturer.

Read and follow all installation instructions.

**

Orifice

Diameter

1/4 in.

*

(6 mm)

1/8 in. 

(3 mm)

Pressure

4 ft. oil – 15 ft. oil

(1.2 m oil – 4.6 m oil)

10 psig – 30 psig 

(68.9 kPa – 207 kPa)

[.69 – 2.07 bar]

Flow Rates

4.7 GPH - 31.0 GPH

(17.8 LPH - 117.3 LPH)

16.9 GPH - 32.1 GPH

(63.7 LPH - 121.5 LPH)

*

Standard

NOTE:

Friction losses due to piping 

NOT

considered.

LM-92164N page 1 of 4

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