Murphy Series LM300 User Manual
Warning, Installation instructions for level maintainers, Model series lm300
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
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
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