Murphy WD300-LV User Manual

WS-93002N page 1 of 7

Murphy W-Series Engine Panels
General Installation Instructions

WS-93002N

Revised 04-06

Section 30

(00-02-0191)

Mounting the Panel

1. Select a suitable mounting location on or near the engine. The location
should provide easy access to the panel and provide unobstructed
viewing of the Swichgage instruments.

2. The mounting location should avoid shock and vibration to the extent
possible. Generally, a location low on the engine is preferred. Avoid
mounting on top of the engine if possible. Shockmounts are
suggested where possible to dampen shock and vibration.

IMPORTANT: Use of improper shockmounts can accelerate the shock
and vibration effects. Consult the factory if you are in doubt.

NOTE: If shockmounts are used, it is suggested that a separate ground
wire be attached to the panel assembly and to the engine. This assures
electrical continuity between the Swichgage contacts and the battery
ground across the shockmounts (see mounting detail below).

Connecting the Pressure Swichgage

1. Pressure tubing is generally not provided. Use of good quality flexi­ble pressure tubing/hose and fittings is strongly suggested. Use at
least

3

/16 in. (5 mm) I.D. tubing. If using copper or rigid

tubing, install at least 12 in. (305 mm) flexible hose from the pres­sure Swichgage instrument to the rigid tubing. This prevents damag­ing vibration from reaching the Swichgage instrument.

2. Connect the pressure tubing to the

1

/8-27 NPT pressure port of the

pressure Swichgage instrument. Use of a non-hardening thread seal­ing compound is recommended although the thread is “dry seal”. Be
sure that thread sealant does not foul the pressure orifice.

NOTE: The orifice can be removed for cleaning.

3. Connect the pressure tubing to the pressure galley of the engine.
Generally this is at the oil filter housing. Use of non-hardening
thread sealant is recommended. Avoid droops or sink traps in
routing of the pressure line.

GENERAL INFORMATION

Installation Accessories

Tools and equipment needed:

●

Thread sealant or Teflon®tape.

●

Straight edge screwdriver (medium).

●

Wire stripping and terminal crimping tools.

●

Electrical wire for use on power connections.

●

Adjustable wrench or open end wrench set.

Read the following information before installing. These installation instructions are typical for a variety of W-Series engine panels and may
not reflect the exact configuration for your panel assembly. It is assumed that the installer is familiar with engine operations and has basic
mechanical and electrical skills. If additional assistance is needed, please call your Murphy dealer or contact one of our offices at the numbers
listed on this instruction sheet. A visual inspection for any damage which may have occurred during shipping is recommended.

WD300-LV

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.

WARNING: Perform mounting operation with power source OFF.

Disable the engine so it cannot start. Remove the battery ground cable.

INSTALLATION INFORMATION

Description

Generally, pressure and temperature Swichgage®contacts are wired to a
central nerve center called a Magnetic Switch or Tattletale

®

annunciator.
This nerve center is essentially a relay and, when signaled by a
Swichgage contact operation, it either makes or breaks a circuit to oper­ate an alarm or engine shutdown device. Various nerve centers are used

depending upon the operation to be performed, the type of electrical
power available and the type of alarm or shutdown device used.
Typical wiring diagrams for the popular Tattletale annunciators and magnet­ic switches are included in this instructions. If a drawing of the specific
model number is enclosed, refer to that drawing for specific wiring.

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.

WARNING

nut and
washer

panel

electrical
ground jumper

DETAIL

shockmount

engine

nut and
washer

panel

engine
frame

WS-93002N page 2 of 7

INSTALLATION INFORMATION continued

Connecting High Temperatur e
Swichgage instrument

LIQUID COOLED ENGINES:

1. Drain engine coolant to a level below the temperature sensing con­nection/plug. This connection is on the engine side of the thermostat
generally near the thermostat housing. Consult your engine manual.

2. Remove adapter nut from temperature sensing bulb and union nut.

3. Apply a non-hardening thread sealant to the adapter nut and screw
securely into the water jacket opening on the engine.

4. Route the temperature capillary away from hot surfaces such as
exhaust manifolds.

5. Place the sensing bulb into the adapter nut and observe that the sens­ing bulb does not “bottom” in the water jacket nor are there other
obstructions in the water jacket opening. Secure sensing bulb into
the adapter nut with the

5

/8-18 union nut. See mounting detail below.

6. Coil excess temperature capillary into a 2 in. (51 mm) diameter

minimum coil. Tie the coil to prevent excessive movement.

Sensing Bulb Mounting Detail

AIR COOLED ENGINES:

Temperature for air cooled engine can be measured in the cylinder head or
in the lubricating oil. Oil temperature will give a more uniform reading
than cylinder head since the oil circulates throughout the engine. Refer to
specific instructions supplied, if any, for your specific application.

1. Oil Temperature
a. The Swichgage sensing probe must be fully immersed in the oil

pan, oil filter housing, oil cooler, etc. depending on engine
model and configuration.

b. Observe all precautions for liquid cooled engines.

2. Cylinder Head Temperature
a. Generally the cylinder head must already have a hole drilled

and tapped for insertion of the temperature sensing probe.

b. If a hole is not provided in the cylinder head and no provision

is made to drill and tap one, it may be possible to install an
external bolt on heat sink such as the Murphy HS7.

c. Coat the temperature sensing probe with a high temperature

grease. A mixture of silicone and graphite flakes is recom­mended although grease alone can be used.

d. Observe all precautions for liquid cooled engines.

Installing the Engine Stop Device or Alarm

Follow instructions provided with the stop device or alarm.

Electric Wiring

1. Disconnect the battery ground cable or otherwise disconnect
electric power from the engine and panel.

2. See the appropriate typical or specific wiring diagram for the nerve
center/magnetic switch in your panel.

3. Generally you will only be required to wire the battery or other electri­cal power to the nerve center/magnetic switch and the output circuit
from the nerve center/magnetic switch to the alarm or shutdown device.

4. Ammeters should be direct wired according to the wiring included
with this panel. Use minimum 10 AWG cable.

5. Be sure that the connected load(s) does not exceed the voltage and
current ratings of the nerve center/magnetic switch or Swichgage.

Placing Into Operation

1. Refill oil and coolant to proper levels.

2. Reconnect electrical power.

3. Service the engine as required by the engine manufacturer before
attempting to start the engine.

To Start the Engine

1. Fully depress the red or black push button of the nerve center/mag­netic switch on the panel face. Hold in the button while cranking the
engine. This overrides the engine shutdown to allow starting. When
the oil pressure pointer moves away from the pointer contact (or
when pressure exceeds the preset low trip point) release the push
button. The engine should be operating. If the push button is red, it
should remain depressed. If the push button is black, it should
return to an extended position.

2. Allow the engine to warm up and the thermostat to open. Slightly
loosen the 5/8-18 union nut on the temperature sensing bulb to allow
trapped air to escape from the cooling system. Retighten the nut.

3. Loosen the oil line fitting slightly at the pressure Swichgage to
allow trapped air to escape from the tubing. Retighten the fitting.

To Stop the Engine

1. Return the engine to idle speed and unload any driven equipment.

2. DISTRIBUTOR IGNITION engine panels may have an
Emergency Stop Button, a start key switch or other power on/off
switch. Operate that switch or button. The nerve center/Magnetic
Switch will trip and open the ignition circuit to stop the engine.

3. DIESEL ENGINES may be equipped with “energized to RUN” or
“energized to STOP” devices. For “energized to RUN” devices such
as Murphy SV series fuel valves or RP-type solenoids, operation is
identical to above for distributor ignition engines. The “energized to
RUN” device is de-energized and the engine stops. For “energized
to STOP” devices the nerve center/magnetic switch applies battery
power to the stop device. Power is removed after a short time delay
depending on the specific nerve center/magnetic switch.
See instructions supplied with the shutdown or alarm device.

For normal stop, pull the manual stop cable.

CAUTION: Do NOT cut or bend the temperature capillary at a
sharp angle. Excess capillary must be carefully coiled and
secured. The temperature sensing bulb must be immersed

directly into the water jacket flow to sense coolant temperature. Do NOT
install into a tee or other fitting. Use only Murphy adapter nuts.

CAUTION: If the pressure Swichgage is equipped with a face mounted
lockout push button, be sure that pressure has been established and
that the lockout mechanism has disengaged. Failure to disengage will

prevent the Swichgage control from operating on low pressure.

WARNING: Perform this operation using appropriate protection.
Trapped air and coolant may cause skin burns.

CAUTION: You should stop the engine in a normal manner.
Turn off the power switch, pull shutoff cable, etc. Do NOT use
the Swichgage control instrument as a normal shutoff.

CAUTION: Never check for voltage by shorting a wire or terminal to
ground. This will ALWAYS damage the electrical components.

CAUTION: Do NOT apply too much grease. If grease is pushed out of
the hole when temperature probe is inserted, remove some grease.

CAUTION: The Swichgage contacts are “pilot duty”. Generally a
nerve center/magnetic switch or relay is required between the

Swichgage contacts and the shutdown or alarm device. Failure to
use a nerve center/magnetic switch will result in contact failure in
the Swichgage and failure of the shutdown or alarm device to operate.

capillary

engine block

sensing
bulb
insertion

union
nut

adapter
nut

coolant
flow

Sensing
bulb

WS-93002N page 3 of 7

Setting the SWICHGAGE® contacts

1. Face mounted contacts are set using a 1/16 in. hex wrench.

2. Some models such as 20PE, 20TE, etc. may not have field adjust­ment. Consult the factory if in doubt.

3. Observe the “normal operating” oil pressure and coolant tempera­ture readings. Set the oil pressure Swichgage contact slightly below
the minimum reading observed or slightly above the minimum
pressure recommended by the engine manufacturer.

4. Set the temperature Swichgage contact slightly above

the “normal

operating” temperature reading observed or slightly below the maxi­mum temperature recommended by the engine manufacturer.

NOTE: More detailed instructions are contained in Installation Sheet
P-95033N for pressure Swichgage instruments and T-8446N for
Temperature Swichgage instruments.

Testing the SwichgageInstruments

For face mounted contacts (20P, 20T, 20PW7, etc.):

1. With the engine running; use a

1

/16 in. hex wrench to rotate the con-

tact until it touches the gauge pointer. Do NOT force the contact
against the pointer. Engine should shut down and/or alarm should
operate. Reset the contact.

2. An alternative method of testing the
shutdown circuit is to place a coin
or other metal object between the
contact adjustment and the bezel.

NOTE: This method does NOT test
the actual contact pair. It does test the
circuit beyond the contact.

3. VER

Y IMPORT

ANT

Each time you
start the engine, observe that the Swichgage instruments are indicat­ing pressure or temperature, etc. Visual inspection and regular test­ing should be normal procedure to ensure proper operation and to
achieve maximum results from your Swichgage system.

WARNING: If the pressure Swichgage instrument has a
lockout push button on the face, a contact setting higher than the
factory setting will make the lockout device inoperative.

CAUTION: This wiring is typical for Murphy W-Series small engine panels. Items shown may or may not be included in your panel;
however, the circuit is typical of how the component will be wired if it is included. Refer to installation instructions for the specific
component if included. For off-panel items such as shutdown devices, see specific instructions supplied with the device.

TYPICAL WIRING DIAGRAM WITH 117PH MAGNETIC SWITCH

C

S

B

B

+

GRDSIG

_

+

Ignition coil

Distributor

Fuel Valve

Rack Pull Solenoid

(RP2300 Series shown)

Tachometer

Hourmeter

Voltmeter

117PH

20T

Temperature

20P

Pressure

Ammeter

Battery

_

+

_

+

_

+

ST

ACC

IGN

BAT

Start

Switch

Alternator

To Magnetic Sensor,
Alternator “Tach”
Terminal, or
Signal Generator

B

+

Energized

to Run

Model 117PH

Use for 12 or 24 VDC

PB128S Stop Switch

Other

Swichgage instruments

Starter

S

B

Exciter