OS77 Series Single Set Point Switch
Installation and Operation Instructions
FRANK W. | ® |
| MFR. |
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
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.
OS77 Series
Description
The OS77 Series single set point speed switch is a compact,
OS77 Module Dimensions
trip set point potentiometer.
Standard OS77 models provide a transistor output when tripped. Models with a relay output are available.
The OS77 is used for protecting the engine from excessive or insufficient oper- ating speeds. As the engine speed reaches the adjustable set point setting, the OS77 will cause the engine to shutdown.
Models are available with Normally Open or Normally Closed circuit and available recrank feature which inhibits starter
(64 mm)
5
(60 mm)
1 2 3 4
Speed Adj.
Potentiometer
(54 mm)
Mounting Schematic
Specifications
Power Supply: Voltage: 7-28 VDC.
Maximum Current: 100 mA.
Frequency Signal:
Voltage, Magnetic Pickup Signal Models
•Minimum: 1.2 Vrms
•Maximum: 30 Vrms
Voltage, Distributor Ignition Models
•Minimum: 6 Vrms
•Maximum: 30 Vrms
Maximum Current, Magnetic Pickup Signal Models: 0.12 mA
Mounting
Hardware
Potentiometer Panel Locknut
Positioning Polycarbonate
postenclosure
Speed Adj.
Potentiometer Terminal #5 used for Relay output models
Maximum Current, Distributor Ignition Models: 0.12 mA
Adjustment Range, Magnetic Pickup Signal Models:
Adjustment Range, Distributor Ignition Models:
•
•Recrank model: dropout 54 Hz
Reset Differential, Distributor Ignition Models
•
•Recrank model: dropout 2.4 Hz
Output:
•Transistor Sink to Ground Resistive Load: 2 A, 28 VDC
•Relay Output Models: 5 A, 250 VAC
Adjustment:
Temperature Range:
Mounting Instructions
The OS77 module is designed to be mounted in a flat panel.
1.Drill the mounting holes as shown on the template included with the packing.
2.Insert the module from the back side of the panel (refer to schematic above).
3.Secure the OS77 module using the mounting hardware included.
Installation Accessories
Hardware tools and optional equipment needed to install the OS77:
●Tools as needed for system mounting such as drill and screw driver
●18 AWG wire for extension and hook up
●Wire termination tools and ring or spade wire termination.
●Voltmeter or test lamp for set up and adjustments.
