Operating Temperature Range, Warranty

Crankcase Level Switch

L-7229B

Revised 02-97

Catalog Section 15

(00-02-0059)

L971 Series

■Durable Low Level Switch■Replaces Non-Explosion-proof Switch on Ingersoll-Rand Compressors■Adaptable to Other Compressors

■Installs with Minimal Downtime

■Two Year Limited Warranty

Description

The Murphy L971 Series Level Switch detects low oil level in a compressor’s crankcase. As oil level in the crankcase depletes, the float on the L971 switch falls, and if reaches the predetermined limit, will trip the internal snap-switch which in turn will initiate a shutdown and/or alarm.

The L971 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. A 304 stainless steel float is available on certain configurations (see Specifications).

Specifications

Operating Temperature Range:

-15 to 275°F (-26 to 135°C).

Maximum Working Pressure:

30 psi (206 kPa) [2.06 bar].

Switch Rating: 4 A @ 250 VAC.

Material

Case: Aluminum (explosion-proof).

Mounting Adaptor: Brass.

Floats: Rigid polyurethane. 304 stainless steel available on L971-C only.

Other Wetted Parts: 303, 304, and 316 stainless steel.O-Ring Seals: Viton and Buna.

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. Wire: 18 AWG (0.75 mm2).

Shipping Weight: 1 lb. 10 oz. (0.7 kg).

Shipping Dimensions: 8-1/4 x 4-1/4 x 4-1/2 in. (210 x 108 x 114 mm).

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.

Wiring Diagrams*

Model L971-A

Green

Red

Yellow

All Other Models