Murphy Selectronic SS300 Series User 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 rec-
ommended 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
WARNING
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.
SPEED SWITCH
1
PICKUP
INPUT
-BATT
+BATT
GND. FOR
T/D
POS. TO
LATCH
ENERGIZE
SPEED
ADJ.
DE-ENERGIZE
2
3
4
5
6
7
8
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

Murphy Selectronic SS300 Series Specifications

General

Brand	Murphy
Model	Selectronic SS300 Series
Category	Switch
Language	English

Summary

General Information

Product Description

SS300 Series are single set point speed switches with SPDT relay dry contact output.

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 PTOs, 4-wheel drives, etc. according to engine speed.

Engine and Transmission Alarm/Shutdowns

Select between two pressure switch set points according to engine speed for protection.

Adjustable Differential Model

The 'AD' model adjusts the speed range for pull-in and drop-out differentials.

Specifications

Power Requirements

Details voltage requirements (12VDC, 24VDC) and frequency signal specs.

Maximum Current

Specifies maximum current draw for pull-in and pickup only.

Frequency Range

Lists frequency ranges for various SS300 models like LF and AD.

Differential Settings

Details differential Hz for Standard and 'AD' magnetic pickup/alternator models.

Output and Time Delay

Specifies relay output type, load rating, and optional 2-6 second delay function.

Operating Conditions

Specifies temperature range, humidity limits, and case material.

Mounting and Wiring

Mounting Dimensions

Illustrates dimensions for mounting the SS300 Series units using screws.

Input Source Wiring

Instructions for connecting magnetic pickup, alternator tach, and distributor ignition inputs.

Latching Overspeed with Solenoid

Shows latching overspeed setups with fuel solenoids (energize to run/stop).

Typical Wiring Installations

Non-Latching Overspeed with Solenoids

Applications with air shutoff or 518PH magnetic switch and fuel solenoid.

Throttle Controller Integration

Using SS300 with AT-67207 for engine speed limiting via OPL pressure.

Dual Set Point Pressure Switch

Application using the SS300 as a dual set point oil pressure switch.

Clutch Engager Application

Using SS300-AD with a CO-3 engager for speed-controlled clutch engagement.

Speed Setting Adjustment

SS300 and SS300-LF Adjustment

Procedure for adjusting the PICKUP LED and SPEED ADJUST pot.

SS300-AD and SS300-AD-LF Adjustment

Procedure for adjusting SPEED ADJUST and DE-ENERGIZE pots for differential.