Murphy Selectronic SS300 Installation And Operation Instructions Manual

SS-97028N page 1 of 4

Installation and Operation Instructions for
SELECTRONIC

®

Speed Switches

SS300 Series

SS-97028N

Revised 05-04

Section 20

00-02-0286

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 NEC
and local codes.

GENERAL INFORMATION

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.

SS300-AD

Description

The SS300 Series are single set point speed switches with SPDT relay dry contact
output. The trip point is set by a potentiometer. An LED indicates when the signal
source is present. A second LED turns on when the trip point is reached. See Table 1
for available models and requirements. An optional time delay is on board to delay
operation of the relay for 2-6 seconds after the set point has been reached.

The SS300 Series speed switch is intended for installation within a weatherproof
enclosure to protect it from rain, dust, etc.

Overspeed Shutdown

The SS300 Series shuts down the engine if RPM exceeds the pre-set limit.

Speed Sensitive Pull-in/Drop-out

Engage or disengage PTO’s, 4-wheel drives, other switch points, etc. according
to speed of engine being monitored.

Engine and Transmission Alarm/Shutdowns

Oil pressure in some engines and transmissions varies widely between running
and idle speeds. The SS300 Series can select between two pressure switch set
points according to speed of the engine or transmission and thus give maximum
protection to the equipment while at operating RPM and eliminate nuisance
alarms when at idle.

Adjustable Differential Model

The (“AD”) can be adjusted to change the speed range over which the pull-in and
drop-out differential of the relay will operate. A typical application is to insure
that engine speed is above a minimum RPM before applying a load but allows a
drop in speed of several hundred RPM without disconnecting the load.

Table 1: Models Available and Input Signal

Specifications

Power Requirements:

12 VDC (9-16 VDC).
24 VDC (18-30 VDC).

Frequency Signal: Voltage (all models):

• Minimum Input Voltage Signal: 4.5 Vrms.

• Maximum Input Voltage Signal: 50 Vrms.

Reset Differential Magnetic Pickup Signal Models:

•

“Standard Models: 2 Hz Differential.

•

“AD” Models (Adjustable Differential): 650-8900 Hz Adjustable

Reset Differential Alternator Models:

•

“LF” Models (Low Frequency): 2 Hz Differential

•

“AD-LF” Models (Adjustable Differential Low Frequency):

50-1900 Hz Adjustable.

Output: Relay contact, SPDT, resistive load, 6 A, 30 VDC.

Time Delay: When terminal 7 is grounded, the relay operation is delayed for

2-6 seconds after rpm set point is reached.

Adjustment: 20–turn potentiometer(s).

Temperature Range: -4° to 185°F (-20° to 85°C).

Relative Humidity: 0 to 95% Non-condensing.

Case: Black, ABS plastic.

Model Number

Distributor

Ignition

Magnetic

Pickup

Alternator

SS300 (std. model) ✗✗✗

SS300-LF (low frequency) ✗✗✗✗

SS300-AD (adjustable differential) ✗✗✗

SS300-AD-LF (low frq. & Adjst. diff.) ✗✗✗✗

Voltage

12 24

Maximum Current 12V 24V

Pull In 46 mA 46 mA

Pickup only 10.5 mA 16 mA

Frequency Range in Hz Model Number

25-2000 SS300-LF

SS300-AD-LF

625-9000 SS300-AD

SS300

SPEED SWITCH

WARNING

1

2

3

INPUT

4

-BATT

5

+BATT

6

GND. FOR

7

POS. TO

8

LATCH

PICKUP

ENERGIZE

SPEED

ADJ.

T/D

DE-ENERGIZE

SS-97028N page 2 of 4

MOUNTING DIMENSIONS

The SS300 Series models can be mounted to a flat surface within
the panel using two #8 screws. Mounting screws are not supplied.

TYPICAL WIRING INSTALLATION

CAUTION:

BEFORE PERFORMING THE WIRING OPERATION TURN THE POWER SOURCE

OFF AND STOP YOUR ENGINE.

CAUTION:

THE SS300 SERIES MODELS ARE INTENDED FOR INSTALLATION WITHIN A WEATHER-

PROOF ENCLOSURE.

Figure 1:

Magnetic Pickup Input

Figure 2:

Alternator Tach., Input

Figure 3:

Distributor Ignition Input

Figure 5:

Energize to Stop Solenoid

CAUTION:

If replacing an SS100 Series
model with an SS300 Series model, note the
significant wiring differences on the SS300

terminals: 5, 6, 7, and 8. Wire your SS300 accordingly.

Figure 4:

Energize to Run Solenoid

Frequency/RPM Input Source

Connect the SS300 Series speed switch to the appropriate frequency/RPM
input source. See Figures 1 thru 3.

Latching Overspeed with Fuel Solenoid

A latching overspeed switch with fuel solenoid application is shown in
Figures 4 and 5. Ignition switch must be turned off to unlatch.

SS300 Series
(all models)

3/16 in. (5 mm)
dia. two places

SPEED

1

2

Magnetic Pickup

+--

Battery

Ignition

Switch

3

4 INPUT

5 – BATT.

6 + BATT.

GND. FOR

7

T/D
POS. TO

8

LATCH

SS300

1-1/32 in.

(26 mm)

2-1/2 in.
(64 mm)

3 in.

(76 mm)

2 in.

(51 mm)

2-1/16 in.

(52 mm)

To Alternator

Tach. Terminal

+--

Battery

--

+

Coil

+--

Battery

Ignition

Switch

Ignition

Switch

1

2

3

4 INPUT

5 – BATT.

6 + BATT.

GND. FOR

7

T/D
POS. TO

8

LATCH

1

2

3

4 INPUT

5 – BATT.

6 + BATT.

GND. FOR

7

T/D
POS. TO

8

LATCH

SPEED

SS300

SPEED

SS300

Speed
Signal

Fuel

Solenoid

Battery

Energize to stop

Solenoid

Speed
Signal

Battery

SPEED

1

2

3

4 INPUT

5 – BATT.

6 + BATT.

GND. FOR

7

T/D
POS. TO

8

Ignition

+--

Switch

LATCH

SS300

SPEED

1

2

3

4 INPUT

5 – BATT.

6 + BATT.

GND. FOR

7

T/D
POS. TO

8

Ignition

+--

Switch

LATCH

SS300

SS-97028N page 3 of 4

TYPICAL WIRING INSTALLATION (continued)

Non Latching Overspeed Switch with
Air Shutoff Solenoid

A non-latching overspeed switch with air shutoff solenoid application is
shown in Figure 6. The air shutoff device must be manually reset to
open/run position.

Non Latching Overspeed Switch with
518PH and Fuel Solenoid

A non-latching overspeed switch with an 518PH magnetic switch and a
fuel solenoid is shown in Figure 7.

Dual Set Point Oil Pressure Switch

A dual set point oil pressure switch is shown in Figure 8.

SS300 with AT-67207
Throttle Controller

The SS300 with the AT-67207 throttle control is used to limit speed as
shown in Figure 9. Engine speed is controlled by OPL pressure
SWICHGAGE®setting and the AT-67207 throttle control. The throttle
control moves as long as OPL contact is made. If OPL is calling for an
increase in speed and engine speed exceeds the setting of the SS300, a
slow signal is applied to AT-67207. The throttle control will stop if both
fast and slow signals are applied. Engine speed at a constant load will
not exceed the limit set by the SS300.

SS300-AD with Clutch Engager

The SS300-AD can be applied with a Murphy CO-3 engager (Figure 10).
The circuit is designed to engage a clutch after engine speed has increased
to a preset RPM (Example: 1200 RPM), and disengage clutch when
engine speed has decreased to idle (Example: 600 RPM). The adjustable
differential SS300-AD relay is set to pull in at 1200 RPM and drop out at
600 RPM.

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Battery

Air Shutoff

Energized to

Close

Speed
Signal

+--

SS300

4 INPUT

3

2

1

5 – BATT.

6 + BATT.

7

8

SPEED

GND. FOR
T/D

POS. TO
LATCH

Battery

Fuse

Oil

Pressure

Water

Temperature

Fuel

Solenoid

518PH

TATTLETALE

®

Speed
Signal

G

B

NC

SW1

SW2

+--

SS300

4 INPUT

3

2

1

5 – BATT.

6 + BATT.

7

8

SPEED

GND. FOR
T/D

POS. TO
LATCH

Battery

Speed Signal

To alarm or

shutdown

Circuit

On - Off

Switch

N.C.

N.O.

C

+--

SS300

4 INPUT

3

2

1

5 – BATT.

6 + BATT.

7

8

SPEED

GND. FOR
T/D

POS. TO
LATCH

Battery

AT-67207

Battery

Slow

Fast

Speed
Signal

Pressure

SWICHGAGE

®

+--

SS300

4 INPUT

3

2

1

5 – BATT.

6 + BATT.

7

8

SPEED

GND. FOR
T/D

POS. TO
LATCH

Battery

CO-3

Common

Disengage

Engage

1

2

3

4

5

Speed
Signal

+--

SS300

4 INPUT

3

2

1

5 – BATT.

6 + BATT.

7

8

SPEED

GND. FOR
T/D

POS. TO
LATCH

CAUTION:

If replacing an SS100 Series
model with an SS300 Series model, note the
significant wiring differences on the SS300

terminals: 5, 6, 7, and 8. Wire your SS300 accordingly.

SS-97028N page 4 of 4

SPEED SETTING ADJUSTMENT

For Models SS300 and SS300-LF

NOTE: The adjustment control(s) is a 20-turn potentiometer(s) and
have no stops when the extreme settings are reached. Always turn a
full 20 turns.

1. Make sure the PICKUP LED light is “ON”. The PICKUP LED will

be flashing for a low frequency (under 30 Hz) and will remain “ON”
for a higher frequency.

2. Turn the SPEED ADJUST pot fully clockwise 20 turns (Figure 13).

3. Run the engine at the desired RPM and adjust the SPEED ADJUST pot

counterclockwise until the ENERGIZE LED comes “ON” and the
relay has transferred (Figure 13).

For Models SS300-AD and SS300-AD-LF

1. Make sure the PICKUP LED light is “ON”. The PICKUP LED will be

flashing for low frequency (under 30 Hz) and will remain “ON” for a
high frequency.

2. Turn the SPEED ADJUST pot fully clockwise 20 turns (Figure 14).

3. Turn the DE-ENERGIZE pot fully counterclockwise 20 turns.

4. Run the engine at the desired RPM and adjust the SPEED ADJUST pot

counterclockwise until the ENERGIZE LED comes “ON” and relay
has transferred.

5. Reduce the engine speed to the desired drop out point.

6. Adjust the DE-ENERGIZE pot clockwise until the ENERGIZE LED
goes “OFF” and the relay has dropped out (Figure 14).

ENERGIZE

SPEED

PICKUP

LED

Lights

20 turn

potentiometers

SPEED

ADJ.

DE-ENERGIZE

Figure 13

Figure 14

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

R

E

G

I

S

T

E

R

E

D

USA–ISO 9001:2000 FM 28221

UK–ISO 9001:2000 FM 29422

Printed in U.S.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