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)

LM-92164N page 3 of 4

TYPICAL INSTALLATION continued

Crankcase (Oil Pan) Mounting

1. Install the universal bracket to the crankcase using the existing

crankcase bolts (Figure 3A). Crankcase bolt diameter must be no larger
than 7/16 inch (11 mm).

NOTE: Check clearance between crankcase and mounting bracket
before installing the mounting bracket. If space between the crankcase
and mounting bracket does not allow installation and access to the
adjustment bolts advance to Step 3.

2. Mount the LM300 to the universal bracket using two 3/8-16 UNC x 1

inch bolts supplied. DO NOT tighten the adjustment bolts too tight. You
will have to adjust the LM300 later in the installation process.

3. If space between the crankcase and mounting bracket is narrow, install

the universal mounting bracket to the LM300 before installing to the
crankcase oil pan.

Connecting Fittings and Hoses

The following instructions are for all LM300 series level maintainers.
All steps that reference oil inlet or oil supply tank DO NOT apply to
non-level-maintaining models. Also, these instructions are based on the
Murphy optional hose kit described on page 1. If you did not order the
optional hose kit, gather the hoses, clamps and fittings as specified in
the optional hose kit.

1. Install the LM300 fittings in their proper locations. NOTE: Apply a

sealant such as teflon, to all threaded connections.

2. Attach the 1 inch (25 mm) diameter, flexible monitoring hose to the

crankcase and the monitoring port on the LM300. See Figure 4.
CAUTION: The hose must slope slightly downward from the LM300
and MUST NOT have any droop or low spots.

NOTE: If the drain plug on the crankcase
is used for the connection, we
recommend installation of a tee to
allow draining of the crankcase
for service.

3. Install the 1/2 inch (13 mm)

I.D. x 3 ft. (914 mm) hose to
the vent connection on the
LM300 to the vent connection
on the crankcase. See Figure 4.

The vent connection on the
crankcase must be well above the
regulated oil level. All hoses must

be clear of obstructions.

BEFORE CONTINUING, VERIFY THAT ALL HOSE CLAMPS
ARE TIGHT.

4. Fill the crankcase to the proper oil levels. With the engine running and

warm, loosen the mounting bracket adjustment bolts and adjust the
LM300 so that the oil level in the sight gauge is aligned with the white
“index line” on the dial (Figure 4). Tighten the adjustment bolts securely.

Connecting the LM300 to an Oil Supply Tank
(level maintaining models only)

1. Remove the caplug from the oil inlet connection. Be sure the filter, inside

the connection, is clear of debris. Install the oil inlet connection.

2. Connect a 1/2 inch I.D. (13 mm) or larger hose

to oil inlet fitting on the LM300 and to the shutoff
valve on the oil supply tank. See Figure 5. For
models LM300 thru LM305 recommended
minimum mounting of the oil supply
tank above the LM is 4 ft. (1.2m);
maximum 15 ft. (4.6m). The
hose must maintain a
downward slope and not have
low spots or droops.
Maximum head pressure
rating using standard 1/4 in. (6
mm) orifice is 15 ft. (4.6
meters). See Flow Rate test on
page 1 for additional orifice pressure
ratings.

3. Before filling the supply tank with

oil, be sure the tank is clean and dry andthe shutoff valve is closed.
Also, be sure all hoses and clamps are tight. Fill the tank with CLEAN
oil.

4. After oil supply tank is full, open the shutoff valve.

Next, make the proper electrical connections for the application. See
contact ratings on page 1 and schematics on page 4.

Switch Test

(switch models only)

To test the shutdown and/or alarm functions
perform the following:

1. Unscrew protective boot from test knob.
IMPORTANT: Always replace boot after

testing.

2. Turn the test knob 1/4 turn to the right
(clockwise), for low test indication (Figure 6).

3. Turn the knob 1/4 turn to the left
(counterclockwise), for high test indication. DO NOT FORCE

THE TEST KNOB TO TURN.

NOTE: After the engine shuts down, you will notice that the oil in the

sight gauge glass will rise above normal running level, possibly
showing an overfill condition. This is a result of “drain-back” to the
engine crankcase and it is normal. Therefore, on models LM302 and
LM303 it may be necessary to wire the high level shutdowns into a
class “B” or “C” (bypass until first time safe) lockout, so as to allow a
permissive start. After the engine is re-started the level will pull down
to the normal running level and the shutdown features will be active. A
modulating valve (Thumb-Valve™) in the level maintaining models
will allow oil usage to be made-up continuously during operation.

Adjustment
Bolt

Figure 3B

Crankcase

Universal
Bracket

Crankcase
Bolt

Note Clearance
before mounting

Figure 3A

Viewing
Lens

Monitoring Hose

Crankcase

Oil Level

Running
Engine

Vent
Hose

Oil Inlet
Hose

Figure 4

Oil Inlet
Hose

Oil Supply
Tank

Figure 5

Figure 6

WARNING: Overfill condition can be caused by excessive

inlet pressure, (maximum inlet pressure depends on orifice),
and/or improper “vent to crankcase” installation.
See Flow Rate Test on page 1 for maximum pressure.

LM-92164N page 4 of 4

OPERATING RANGES OF SWITCHES

SWITCH WIRING DIAGRAMS

LM301

SPDT

LM302

High/Low N.O.

DPST

LM303

High/Low N.C.

DPST

LM304

Alarm before

shutdown N.O.

DPST

LM305

Alarm before

shutdown N.C.

DPST

Figure 7: LM301

Figure 9: LM304/LM305

Figure 8: LM302/LM303

This section applies only to models that have built-in switches. The illustrations
below and to the right show the dials and their operating ranges of the switches.
If levels are within the designated zones the switch(es) will activate. Notice that
a switch is capable of activating approximately 3/8 in. (10 mm) from the top of
the high zone and 3/8 in. (10 mm) from the bottom of the low zone. The dial in
Figure 9 shows that if level continues to drop into the low-low zone, a
shutdown will occur.

NOTE: Color zones on dial face show approximate normal operating zones.
Actual conditions may vary depending upon operating characteristics of the
engine. Placement of the LM300 according to the above instructions will
compensate for these conditions.

WARNING: DISCONNECT ALL ELECTRICAL POWER BEFORE CONNECTING ANY WIRES.

CONTROL SYSTEMS & SERVICES DIVISION

P.O. Box 1819; Rosenberg, Texas 77471; USA
[phone] fax [phone]

e-mail [e-mail]

MURPHY DE MEXICO, S.A. DE C.V.

Blvd. Antonio Rocha Cordero 300, Fracción del Aguaje
San Luis Potosí, S.L.P.; México 78384
[phone] fax [phone]
Villahermosa Office [phone]
e-mail [e-mail]
www.murphymex.com.mx

FRANK W. MURPHY, LTD.

Church Rd.; Laverstock, Salisbury SP1 1QZ; U.K.
[phone] fax [phone]
e-mail [e-mail]
www.fwmurphy.co.uk

MURPHY SWITCH OF CALIFORNIA

41343 12th Street West
Palmdale, California 93551-1442; USA
[phone] fax [phone]
e-mail [e-mail]
www.murphyswitch.com

In order to consistently bring you the highest quality, full featured products, we reserve the right to change our specifications and designs at any time.

MACQUARRIE CORPORATION

1620 Hume Highway
Campbellfield, Vic 3061; Australia
[phone] fax [phone]

e-mail [e-mail]

FW Murphy

P.O. Box 470248
Tulsa, Oklahoma 74147 USA
[phone]

fax [phone]
e-mail [e-mail]

www.fwmurphy.com

R

E

G

I

S

T

E

R

E

D

USA–ISO 9001:2000 FM 28221
UK–ISO 9001:2000 FM 29422

Printed in U.S.A.

Warranty

A limited warranty on materials and workmanship is given with this FW Murphy product.

A copy of the warranty may be viewed or printed by going to www

.fwmurphy.com/support/warranty.htm

Yellow

Normal

Low

Float

Green

Black

Red

Yellow

Green

Black

High

Normal

Low

High

Normal

Red

Low

Float

Blue

High

Normal

Low

High

Normal

Low

Float

Green

Brown

Orange

3/4 in.

(19 mm)

3/4 in.

(19 mm)

Yellow

Float

3/8 in.

(10 mm)

3/8 in.

(10 mm)

Normal

Low

Low-Low

Normal

Low

Low-Low

Green

Black

Red

Blue

Normal
Operating Range

Low Zone
Shutdown or Alarm

Float

High Zone
Shutdown or Alarm

Normal
Low

Low-Low

Normal

Low

Low-Low

Green

Brown

Orange

(19 mm)

3/4 in.

Normal
Operating Range

Low Zone Alarm
Low-Low Zone Shutdown

3/8 in.

(10 mm)

Normal
Operating Range

Low Zone
Shutdown or Alarm

3/4 in.

(19 mm)

3/8 in.

(10 mm)

1/4 in.

(6 mm)