End Devices
Tattletale annunciators and magnetic switches are the nerve centers that translate Swichgage contact operations into decisions and operate the alarm or shutdown device. These switches are the electrical load carrying devices for the alarm or shutdown device. Tattletale annunciators indicate which monitored function failed leading to the alarm or shutdown; magnetic switches do not. Magnetic switches operate basically as a latching relay.
Magnetic switches and Tattletale annunciators are available for use with engines or electric motors. Various circuits, time delays and contact configurations are available to match the power source and mode of operation required for alarm only, alarm before shutdown or shutdown only.
For distributor ignition engines, the magnetic switch opens the distributor coil circuit to cause shutdown. For magneto or CD ignitions the magnetic switch grounds the ignition output. Some models can also trip fuel valves instead of or in addition to grounding the ignition. Diesel engines are shut down by either closing off the fuel or air supply. Magnetic switches and Tattletale annunciators can make or break circuits for these engines.
For electric motor application, various magnetic switches are available to operate the motor starter, holding coil directly or in conjunction with appropriate Murphy Transformer-Relay assembly.
Sales Bulletin: Tattletale Annunciators & Magnetic Switches
78793 rev. 2014/09/27
Sales Bulletin: 518PH/518APH/518E
00-02-0187 rev. 2016/02/25
Typical Wiring Tech Sheet: Tattletale Annunciators & Magnetic Switches
97020B rev. 2008/04
Replacement Cross Reference: MS2100
MS21-01085A (00-02-0485) rev. 2001/09
Replacement Cross Reference: MS2110
MS21-01093A (00-02-0487) rev. 2001/10/17
Replacement Cross Reference: MS2111
MS2111-02014A (00-02-0497) rev. 2005/04
Replacement Cross Reference: MS2120
MS21-010945A (00-02-0488) rev. 2001/09
Tattletale annunciators and magnetic switches are the nerve centers that translate Swichgage contact operations into decisions and operate the alarm or shutdown device. These switches are the electrical load carrying devices for the alarm or shutdown device. Tattletale annunciators indicate which monitored function failed leading to the alarm or shutdown; magnetic switches do not. Magnetic switches operate basically as a latching relay.
Magnetic switches and Tattletale annunciators are available for use with engines or electric motors. Various circuits, time delays and contact configurations are available to match the power source and mode of operation required for alarm only, alarm before shutdown or shutdown only.
For distributor ignition engines, the magnetic switch opens the distributor coil circuit to cause shutdown. For magneto or CD ignitions the magnetic switch grounds the ignition output. Some models can also trip fuel valves instead of or in addition to grounding the ignition. Diesel engines are shut down by either closing off the fuel or air supply. Magnetic switches and Tattletale annunciators can make or break circuits for these engines.
For electric motor application, various magnetic switches are available to operate the motor starter, holding coil directly or in conjunction with appropriate Murphy Transformer-Relay assembly.
Sales Bulletin: Tattletale Annunciators & Magnetic Switches
78793 rev. 2014/09/27
Typical Wiring Tech Sheet: Tattletale Annunciators & Magnetic Switches
97020B rev. 2008/04
The PSB switch is a direct-mount switch for critical pressure points. It has one limit contact that can be used to activate an alarm, actuate indicator lights or shutdown equipment.
The construction of this instrument is the same as Murphy’s time-proven Swichgage instrument. A precision machined brass mounting plate and port captures a high-quality, stamped beryllium copper diaphragm. The single-pole, double-throw (SPDT) snap-switch is operated directly from the diaphragm for quick acting and positive switching. Trip point is factory preset according to your specifications.
Housing is weather sealed to prevent entry of moisture, dust, etc. A glass-filled nylon terminal block with screw terminal connections gives the PSB switch a real advantage in industrial engine applications. The PSB is ideal when reading is not desired, but pressure is critical to operational efficiency. Intended for use in general purpose non-classified areas.
Features include:
· Fits all engine applications
· SPDT snap-switch
· Activates indicator lights, alarms or shuts down equipment
· Time-proven Swichgage construction
· Easy wiring terminal block
· Steel housing specially coated to resist corrosion
· Factory preset to your specifications
Sales Bulletin: Model PSB
9104 rev. 2014/10/11
The TSB switch is a direct-mount switch for temperature sensing. It has one limit contact that can be used to activate an alarm, actuate indicator lights or shut down equipment. The construction of this instrument is the same as our time-proven Swichgage. A precision machined brass mounting plate and port captures a high quality stamped beryllium copper diaphragm.
The single-pole, double-throw (SPDT) snap-switch is operated directly from the diaphragm, for quick acting and positive switching. Trip point is factory preset according to your specifications.
Housing is weather sealed to prevent entry of moisture, dust, etc. A glass-filled nylon terminal block with quick-screw terminal connections gives the TSB switch a real advantage in industrial engine applications. The TSB is ideal when reading is not desired but temperature is critical to operational efficiency. Intended for use in general purpose non-classified areas.
Applications include:
· Engine coolant
· Irrigation systems
· Compressors
· Oil field systems
· Engine lubrication
· Construction equipment
· Mobile equipment
· Marine engines
· Generators
· Electric motors
Sales Bulletin: Model TSB
9137 rev. 2015/09/24
Murphy Electronic Speed Switches are available in various configurations to cover a wide variety of applications. These compact devices receive their input signal from various sources depending upon the particular speed switch model and application. They are available in single or dual switch point models, and the switch point(s) are field adjustable.
Models are available in self-contained enclosures and as PC-board design for inclusion in your control cabinet. All Murphy speed switches are designed to operate in harsh environments and have high electrical noise immunity.
Murphy speed switches applications include operating alarms and equipment shutdown. They are ideal for disconnecting starter cranking on auto start systems or overspeed switching.
Features include:
· Generators
· Compressors
· Industrial Engines
· Pumps
· Vehicles
· Farm Equipment
Sales Bulletin: Electronic Speed Switches
97118 rev. 2014/10/31
Installation & Operation Instructions: HD9063 Series
HD-96044N (00-02-0179) rev. 2001/03
The OS77 Series single set point speed switch is a compact, all-electronic, speed sensing module. It is field adjustable and can be panel mounted via its 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 operating 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 re-crank feature which inhibits starter re-engagement until the engine speed is near zero RPM.
Sales Bulletin: OS77 Series
OS-98001N (00-02-0303) rev. 1998/04
Sales Bulletin: Electronic Speed Switches
97118 rev. 2014/10/31
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.
Installation & Operation Instructions: SS300 Series
SS-97028N (00-02-0286) rev. 2004/05
