L-94071N
Revised 09-97
Section 15
Installation Instructions for
L971 Series Crankcase Level Switch
(00-02-0173)
Please read the following information before installing. A visual inspection of this product for damage during shipping is recommended before mounting. It is your responsibility to have a qualified person install this unit and make sure it conforms to local codes.
GENERAL INFORMATION
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.
**
R
Dimensions
Description
The Murphy L971 Series Level Switch detects low oil level in a compressor’s crankcase. It is designed for Ingersoll-Rand Type 30, Type 40
and ESH compressors, yet can be adapted to fit other compressors that
have an inspection plate extending below normal operating oil level.
The L971 has a 1/2 NPT process connection and features an explosionproof enclosure, durable SPDT snap-switch and rigid polyurethane
foam float.
D
Float is removable
and replaceable
1/2 NPT
E
3 in.
(76 mm)
A
Float arm is
adjustable but
cannot be
removed.
Specifications
B
C
Operating Temperature: -15 to 275°F (-26 to 135°C).
1/2 NPT
Maximum Working Pressure: 30 psi (206 kPa) [2.06 bar].
Dimensions in inches* (see drawing above)
Switch Rating: 4 A @ 250 VAC.
Models
Material
Case: Aluminum (explosion-proof).
Mounting Adaptor: Brass.
Floats:
• Rigid polyurethane.
• 304 stainless steel (L971-C only).
Other Wetted Parts: 303, 304, and 316 stainless steel.
O-Ring Seals: Viton and Buna.
L971
B
C
D
E
2-5/8 (67)
5-7/8 (149)
30 (762)
2-1/2 (64)
2-27/32 (72)
L971-A
2-5/8 (67)
5-7/8 (149)
30 (762)
2-1/2 (64)
2-27/32 (72)
L971-B
4-13/16 (122)
8-1/16 (205)
30 (762)
4-5/8 (117)
2-27/32 (72)
L971-C
2-13/16 (71)
6-1/16 (154)
30 (762)
2-7/8 (73)
3-1/8 (79)
L971-D
3-7/8 (98)
7-1/8 (181)
30 (762)
3-3/4 (95)
2-27/32 (72)
L971-E
4-13/16 (122)
8-1/16 (205)
30 (762)
5-1/8 (130)
2-27/32 (72)
L971-F
2-5/8 (67)
5-7/8 (149)
40 (1016)
2-1/2 (64)
2-27/32 (72)
L971-G
2-5/8 (67)
5-7/8 (149)
40 (1016)
2-1/2 (64)
2-27/32 (72)
*Millimeter dimensions are shown in parenthesis ( ).
Process Connection: 1/2 NPT.
Enclosure Rating: UL and CSA listed for Class I, Groups C & D;
Class II, Groups F & G, Hazardous Locations.
Conduit Connection: 1/2 NPT.
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
Wire: 18 AWG (0.75 mm2).
** Products covered by this literature comply with EMC Council directive 89/336/EEC regarding electromagnetic compatibility except as noted.
L-94071N page 1 of 2
INSTALLATION
TYPICAL WIRING
Compressors With Inspection Plate
Shutdown and Alarm Circuit
1. Drain crankcase.
2. Remove crankcase inspection plate (Figure 1).
3. Drill and tap a 1/2 NPT female pipe thread into the inspection plate at
point “A” (Figure 2). CAUTION: Clean area of metal shavings. The
hole is to be a minimum of 2 in. (51 mm) below normal running oil
level (Figure 3).
Line Voltage
Control Voltage
H
Yellow
Black
Red
Alarm Silencer
Crankcase
Switch
Alarm
Inspection
Plate
A
Shutdown Circuit for H.O.A. Operation
H
Figure 2
“TOP” Label
A
HC
Crankcase
Figure 1
O
O
A
Yellow
HC
Black
90°
Oil Level
Normal
Oil Level
Hole
Crankcase
Switch
Inspection
Plate
2 in. (51 mm) Minimum
Conduit
Shutdown Circuit for Start-Stop Push-button Operation
Crankcase
Figure 3
Float
Start
Figure 4
Yellow
HC
4. Unscrew and remove float on the L971 switch.
5. Apply pipe dope to the process connection threads.
6. Thread the L971 switch into crankcase hole until “TOP” label is up (Figure
4). Be sure the float moves freely and there are no obstructions.
7. If adjustment of shutdown level is required, loosen hex set screw on float
attachment. Rotate float attachment to desired level. Retighten set screw.
8. Replace float and reinstall inspection plate and gasket in original position.
9. Install drain plug.
10. Wire accordingly.
11. Fill crankcase to proper level.
Stop
Black
Crankcase
Switch
Alarm Without Shutdown Circuit
Alarm
Alarm Silencer
Yellow
Compressors Without Inspection Plate
REPLACEMENT PARTS
Description
Cover
Cover Gasket
Snap-switch
Part Number
15050443
15050369
00002326
FRANK W. MURPHY, LTD.
Church Rd.; Laverstock, Salisbury SP1 1QZ; U.K.
+44 1722 410055 fax +44 1722 410088
e-mail [email protected]
www.fwmurphy.co.uk
MURPHY SWITCH OF CALIFORNIA
41343 12th Street West
Palmdale, California 93551-1442; USA
+1 661 272 4700 fax +1 661 947 7570
e-mail [email protected]
www.murphyswitch.com
Description
Float
Polyurethane
Stainless Steel
Part Number
15050679
15050356
MACQUARRIE CORPORATION
1620 Hume Highway
Campbellfield, Vic 3061; Australia
+61 3 9358 5555 fax +61 3 9358 5558
e-mail [email protected]
GI
D
MURPHY DE MEXICO, S.A. DE C.V.
Blvd. Antonio Rocha Cordero 300, Fracción del Aguaje
San Luis Potosí, S.L.P.; México 78384
+52 444 8206264 fax +52 444 8206336
Villahermosa Office +52 993 3162117
e-mail [email protected]
www.murphymex.com.mx
Crankcase
Switch
RE
FW Murphy
P.O. Box 470248
Tulsa, Oklahoma 74147 USA
+1 918 317 4100
fax +1 918 317 4266
e-mail [email protected]
www.fwmurphy.com
CONTROL SYSTEMS & SERVICES DIVISION
P.O. Box 1819; Rosenberg, Texas 77471; USA
+1 281 633 4500 fax +1 281 633 4588
e-mail [email protected]
Red
E
1. If installing into a thick wall crankcase, drill and tap a 1/2 NPT
female pipe thread into the crankcase. CAUTION: Clean area of
metal shavings. The hole is to be a minimum of 2 in. (51 mm) below
normal running oil level (Figure 3).
If installing into a thin wall crankcase, drill a hole in the crankcase
slightly larger than outside diameter of a 1/2 in. coupling. The hole is to
be a minimum of 2 in. (51 mm) below normal running oil level (Figure
3). CAUTION: Clean area of metal shavings. Weld a half collar (1/2
NPT) into the hole.
2. Follow steps 4 thru 11 above.
Power Supply
STER
USA–ISO 9001:2000 FM 28221
UK–ISO 9001:2000 FM 29422
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.
Printed in U.S.A.
L-94071N page 2 of 2
">
