Murphy 20P, A25P, 25P, A20P, 20PE Installation Instructions Manual

Installation Instructions for
Transmission/Gear Pressure SWICHGAGE

®

TP-8318N

Revised 05-99

Section 05

(00-02-0164)

Base Model Description

20P, 25P, A20P and A25P SWICHGAGE

®

The gage pointer makes with an adjustable contact to complete a pilot-duty circuit.

20PE, 25PE, A20PE and A25PE SWICHGAGE

®

Features internal snap-acting SPDT switches, instead of the single pole/pointer
contacts. When the switch closes on falling pressure, it becomes Set

, as pres-

sure rises the switch Resets

.

20PABS, 25PABS, A20PABS and A25PABS SWICHGAGE

®

Same as 20P, 25P, A20P and A25P with internal SPDT snap-switch for pre-alarm.

Specifications

Case Material: 20P and 25P Series: Plated steel.

A20P and A25P Series: Polycarbonate.

Pressure Connection: 1/8-27 NPT.

Contact Rating: Standard is 2A @ 30 VAC/DC resistive (pilot-duty only).

Models 20PE, A20PE, 25PE and A25PE have non-adjustable snap-switch
rated 3A @ 30 VDC inductive, 4A @ 125 VAC inductive.

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

IMPORTANT Installation
Recommendations

SWICHGAGE®Used On Transmission/Clutch Oil Pressure

1. Install the SWICHGAGE®using a Murphy pulsation snubber PD2160 in

the pressure connection at the transmission or gear and at the SWICH­GAGE®. The snubber helps reduce pressure spikes/surges which will
damage the gage sensing element. It also stabilizes the gage readout

through all operating cycles. Failure to isolate gage in this manner will

void Murphy warranty and possibly cause equipment damage.

2. Models with pre-alarm have two switch points and when used with Murphy

SS300 speed switch–allows changing between high and low switch points
according to engine RPM. This configuration does away with nuisance
alarms when shifting or when at idle–yet maintains maximum pressure
protection. See Murphy Application Tip AT-01 for further details.

Please read the following information before installing. A visual inspection of this product for damage during shipping is recommended before mounting.

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.

Stainless
Steel Bezel

Polycarbonate
Lens

Adjustable,
Self-Cleaning
Limit Contact

Pulsation
Dampener
(Removable)

Diaphragm
Sensing Element

PD2160

High Pressure Flexible Hose*

*NOTE: A length of flexible hose between the gear and the SWICHGAGE

®

helps dampen pressure surges.

Transmission/Gear

SWICHGAGE

®

CAUTION: Certain dangers to human safety and to equipment
may occur if some equipment is stopped without pre-warning.
It is recommended that monitored functions be limited to
alarm-only or to alarm before shutdown.

Installation TP-8318N page 1 of 1

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

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USA–ISO 9001:2000 FM 28221

UK–ISO 9001:2000 FM 29422

Printed in U.S.A. 113286N

WARNING