Murphy 45 Series - Manual

45-96003B page 1 of 2

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Combination Pressure Swichgage instru-
ment and Built-in Electromagnetic Switch

■

High and Low Contacts Can Disable
Engine’s Ignition Due to Critical Pressure

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Magnetic Switch Will Not Allow Engine
Restart Due to Flywheel Inertia

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Semi-Automatic Low Pressure Override
Push Button for Engine Startup

Description

The 45 Series pressure Swichgage instrument
incorporates a built-in electromagnetic switch
to disable an ignition whenever the gage con-
tacts operate.
Flywheel inertia cannot restart the engine since
the electromagnetic switch will not allow the
ignition to operate until manually reset.
A semi-automatic lockout push button over-
rides the low pressure contact for equipment
startup. The lockout automatically disengages
when pressure is established allowing the low
limit contact to be armed for operation should a
low pressure condition occur.
Models are available for conventional magnetos,
capacitor discharge (CD) ignitions, 12/32 VDC
battery systems, and 120 VAC power sources.

Ranges are available from 30” vac (-101 kPa)
[-1.01 bar] thru 10,000 psi (138 MPa) [1379 bar].

Applications

Recommended instrument for most field gath-
ering pumps, the 45 Series instantly stops your
pump when pressures drop due to line breaks,
l e a k s o r w h e n y o u r t a n k i s p u m p e d o u t .
Overpressure shutdown can occur due to clo-
s u r e o f v a l v e s i n t h e l i n e , o r o t h e r l i n e
restrictions.

Specifications

Dial:

White on black, dual scale, psi and kPa

standard, 4-1/2 in. (114 mm) diameter.

Case:

Die cast aluminum

.

Process Connection:

1/4 NPT thru 1000 psi (6.9 MPa) [69 bar];
1/2 NPT 1500 psi (10 MPa) [103 bar] thru
10,000 psi (138 MPa) [1379 bar].

Overrange:

Do not exceed 10% above full range.

Sensing Element:

Select from bronze or 316 stain-

less steel bourdon tube.

Gage Accuracy:

±2% for first and last quarters of

scale; the middle half is ±1%.

Pressure Relief Disc:

Located in rear of case.

Contact Ratings:

45B =

12/30 VDC coil; 10 A, 32 VD DC contacts

45CD =

CD ignition coil; 10 A contacts

45M =

Magneto ign. coil; 10 A contacts

45N =

120 VAC coil; 10 A, 120 VAC contacts

Wire Connections:

1/2 NPT conduit and terminal block.

Item Weight:

5 lbs 9 oz (2.5 kg) approximately.

Item Dimensions:

10 x 9 x 6 in. (254 x 229 x 152 mm).

Basic Models

45B

Series Swichgage instrument

For use with 12-32 VDC battery ignition systems;
it includes battery ignition type magnetic switch.

45CD

Series Swichgage instrument

For use with (CD) capacitor discharge ignitions;
it includes CD ignition type magnetic switch.

45M

Series Swichgage instrument

For use with magneto type ignitions; it includes
magneto ignition type magnetic switch.

45N

Series Swichgage instrument

For specific use with 110 VAC Power Sources;
it includes 120 VAC type magnetic switch.

8-7/16 in.

(214 mm)

3-3/8 in.

(86 mm)

1/2 NPT

conduit

Dimensions

45-96003B

Revised 07-06

Catalog Section 05

45 Series Pressure Swichgage

®

instrument

To Disable Magneto, CD and Battery Ignition Systems