Murphy LM300 User Manual

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 mm2x 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 1/2 in. (13 mm) I.D. x

3 ft. (914 mm) long hose

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

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

WARNING

LM-92164N page 2 of 4

DIMENSIONS

TYPICAL INSTALLATION

LM300 Series Enclosures

Mounting Brackets with Hardware

)

.

(

)

(

.

.

(

)

15000371 pipe bracket

15000370 universal bracket

The dimensions below are for the optional -EX model enclosure. The
standard model enclosure dimensions are the same except the height and
width which are: 7 in. (178 mm) H, 7-7/8 in. (200 mm) W.

Mounting (all LM300 Series models)

NOTE: Mount the LM300 series level maintainers as close as possible
to the crankcase. Also, excessive vibration can cause overfill. Be sure
mounting brackets are supported.

The following instructions are based on the usage of the pipe and universal
mounting brackets shown above.

Pipe Bracket Mounting

1. Mount a nominal 1/2 inch (21 mm) diameter pipe to the deck of the engine.

2. Install the pipe bracket to the LM300 using two 3/8-16 UNC x 1 inch

bolts supplied. See Figure 1A.

3. Slip the LM300 onto the pipe and install the two adjustment bolts. Each

adjustment bolt consists of a 3/8-16 UNC x 1 inch bolt and two nuts. See
Figure 1B. DO NOT tighten the adjustment screws too tightly because
you will have to adjust the LM300 later in the installation process.

Mounting with Universal Bracket

The universal bracket has two mounting methods: deck mounting and
pan mounting.

Deck Mounting

1. Install the universal bracket to the deck as shown in Figure 2A with two

flat washers and two 3/8 inch (10 mm) diameter bolts (not supplied).

2. Mount the LM300 to the universal bracket using two 3/8-16 UNC x 1
inch (25 mm) bolts supplied (Figure 2B). DO NOT tighten the
adjustment screws too tightly. You will have to adjust the LM300 later in
the installation process.

Pipe

Crankcase

Adjustment
Bolts

Figure 1B

LM300

Pipe
Bracket

Figure 1A

Adjustment
Bolts

Figure 2B

Crankcase

Deck

Universal
Bracket

Threaded
hole

Figure 2A

Additional Hardware
Supplied

(4) 3/8-16 UNC x 1 inch

(25 mm) screws

(4) 3/8-16 nut

(4) 3/8 I.D. lock washer

(2) 3/8 I.D. flat washer

Additional Hardware
Supplied

(2) 3/8-16 UNC x 1 inch

(25 mm) screws

(4) 3/8 I.D. flat washer

(2) 3/8 I.D. lock washer

(2) 3/8-16 nut

Oil Inlet Connection*

Crankcase

1/2-14 NPT

Test

Knob

8-1/4 in.

(210 mm)

*

Applies to level maintaining models only.

Snap Switch
Case Assembly

5-15/16 in.

(151 mm)

2-3/4 in.
(70 mm)

with removable

Vent

7-3/16 in.
(183 mm)

1/2-14 NPT

screen

Monitoring Port Connection

3 places, 3/4-14 NPT

5-3/16 in.
(132 mm)

(152 mm)

3/8-16
UNC-2B
Mounting
Holes, 2 places

6 in.

Electrical

Conduit

1/2-14

NPT

4.50 in.

(114 mm

.376 in

10 mm
minimum
bottom surface
2 places

1/4-20 NC

2 places

Slot, .390 in. (10 mm)
x 2 in. (51 mm)
4 places

Slot, .390 in. (10 mm)
x 4.71 in. (120 mm)
3 places

4.50 in.

(114 mm)

5.19 in.

(132 mm)

5.20 in.

(132 mm)

Hole .88 in.

22 mm) dia

6.69 in.

(170 mm)

7.50 in.
(191 mm)

2.50 in
64 mm

1.75 in.

(44 mm)