US2368471A - Alarm system - Google Patents

Description

F. T. HORAN ALARM SYSTEM Jan. 30, 1945.

Filed April 15, 1942 Inventor I Frank T Horan,

His Attorney.

Patented Jan. 30, 1945 ALARM SYSTEM Frank T. Horan, Scotia, N. Y., assignor to General Electric Company, a corporation of New York Application April 15, 1942, Serial No. 439,043

7 Claims.

My invention relates to supervisory alarm systems and particularly to systems such as are used for indicating undesirable conditions associated with dynamo-electric machines.

An object of my invention is to provide an improved supervisory alarm system for use with dynamo-electric machines and the like.

Further objects and advantages of my invention will become apparent and my invention will be better understood from the following description referring to the accompanying drawing, and the features of novelty which characterize my invention will be pointed out with particularity in the claims annexed to and forming part of this specification.

It has been found desirable to enclose certain types of dynamo-electric machines, and in special circumstances, to provide a special cooling or ventilating medium in such enclosed machines to increase the efliciency thereof by the use of a gas such as hydrogen, or to make the machine explosion-proof by surrounding it with an inert gas such as carbon dioxide. With machines of this type, it is difficult to determine the presence of undesirable conditions associated with the machine without the use of special instruments. In order to detect such undesirable conditions and call them to the attention of an attendant, I provide an alarm system arranged to give the attendant an audible signal indicating the presence of an undesirable condition and a visual signal indicating the nature of the undesirable condition.

In the drawing, I have shown an embodiment of my invention in connection with a dynamoelectric machine In which is adapted to be filled with hydrogen or other suitable gas for cooling.

purposes. In order to assure the operation of the electrical alarm system, it is adapted to be energized by a plurality of sources of electrical power supply, including an alternating current source of power supply H and a direct current source of power supply l2. These t-wo'sources of power supply are adapted to be'connected and disconnected to their respective alarm circuits by circuit breakers l3 and M, respectively. Visual signals including pilot lights I5 and I6 are connected to the sources of power supply I I and I2, respectively, to indicate the ener-gization or deenergization of the respective sources of power supply. A plurality of audible signal devices, such as horns I! and I8, is connected in circuit with the sources of electric power supply H and I2, respectively, cuit breaker is is connected in series with the energizing circuits of these audible signal devices for stopping the operation thereof when desired. Circuit breaker 20 and 2| also are connected in circuit with the audible signal devices I! and I8, respectively, and are adapted to be operated by I a common solenoid controlled relay armature 22.

A solenoid coil 23 is arranged to be normally energized to maintain the circuit breakers 20 and 2| open, thereby maintaining the circuits of the audiblesignal devices I1 and I8 deenergized when the sources of electric power supply I l and I2 are energized. This solenoid is arranged in series with a plurality of sets of circuit breaker contacts 24 and 25 of circuit breakers operable in response to predetermined conditions associated with the dynamo-electric machine l0. Under normal operating conditions with the sources of electric power supply I l and I2 energized, solenoid operating coils 26 and 21 are adapted to be energized by the direct current source of electric power supply l2 through current limiting resistors 28 and 29, respectively, thereby closing the circuits of the contacts 24 and 25 by circuit breaker contactors 30 and 3!, respectively. An-

and a manually operated cirother circuit breaker having contacts 32 connected in series with the circuit breaker contacts 24 and 25 and the circuit breaker operating coil 23 is arranged to be closed by operation of a solenoid coil 33 energized from the alternating source of electric power supply ll". When both of the sources of electric power supply II and I2 are energized and the circuit breakers l3 and I4 are closed, the circuit of the circuit breaker solenoid coil 23 is energized from the directcurrent source of electric power supply through the circuit breaker contacts 24 and the contactor 30, the circuit breaker contacts 25 and contactor 3|, and through the circuit breaker contacts 32 and contactor 34. It is desirable that an audible signal should be given to indicate the failure of power on either of the sources of electric power supply. If the alternating current source of electric power supply I I should fail, the circuit breaker solenoid coil 33 would become deenergized and the circuit breaker contactor 34 would open the circuit between the breaker contacts 32. This would result in the deenergization of the circuit breaker operating coil 23, with the result that the circuit breaker 2| would be closed and the audible signal device I 8 would be energized by the direct current source of electric power supply l2, thereby providing an audible signal indicating an undesirable condition some place in the system. The visual signal pilot light 15 would be deenerglzed, and thereby would indicate that the undesirable condition was the deenergization of the alternating current source of electric power supply. Should the alternating current source of power supply remain energized and the direct current source of electric power supply 12 become deenergized, the circuit breaker operating coil 23 would be deenergized and the circuit breaker 20 would be closed, thereby energizing the audible signal device I! by the alternating current. source of power supply H and {providin an audibl signal indicating that an undesirable condition existed in the system. Under these conditions, an examination of the visual signal devices will indicate that the visual signal pilot light I 8 is extinguished, thereby indicating that the direct current source of electric power sup-- ply is deenergized.

The dynamo-electric machine 10 may be provided with a large number ofinstruments incorporating circuit breakers or switches for closing alarm circuits to indicate the presence of undesirable conditions associated with the dynamoelectric machine. These undesirable conditions might be due to a variety of circumstances, such as excessive temperatures of the windings of the machine, excessive temperatures in the bearings of the machine, the lack of an adequate supply of lubricating oil to the bearings of the machine, the presence of foreign gases in the ventilating medium in the machine, the presence of water within the machine housing, undesirably high or low pressure of the ventilating medium in the machine, and a number of other similar conditions. My improved alarm system is illustrated in the drawing in connection with two of these conditions, asit is obvious that alarm circuit breakers and circuits could be arranged to operate in the same manner by merely locating circuit breakers and the proper instruments for operating such circuit breakers responsive to the presence of any of the above undesirable conditions. An alarm circuit breaker 35 is arranged to be operated by a float 36 responsive to liquid level in the housing of the dynamo-electric machine ID to indicate an accumulation of water or oil from within the housing. The circuit breaker 35 is arranged to be closed if the accumulation of water or oil exceeds a predetermined amount and is connected in a circuit across the circuit breaker operat ing coil 26, so as to provide a shunt across this operating coil in response to a predetermined undesirable amount of accumulated liquid from within the machine housing. This causes a deenergization of the circuit breaker operating coil 26, thereby opening the circuit between the circuit breaker contacts 24 and deenergizing the operating coil 23 of the audible signal device circuit breaker. This causes the audible signal circuit breakers and 2| to close and provide an energizing circuit for the audible signal devices I 1 and 18 which produce an audible signal indicating the presence of an undesirable condition in the system. The deenergization of the circuit breaker operating coil 26 also provides for the closing of a circuit through a visual signal device including a pilot light 31 through circuit breaker contacts 38 and contactor 35. The visual signal given by the pilot light 31' inicates the particular undesirable condition existing in the system, and the operator may then shut off the audible signal produced by the horns l1 and I8 by the operation of a manually operable circuit breaker 4D to close circuit breaker contacts 4|, so as again to energize the circuit breaker operating coil 22 and open the circuit breakers 24 and 2 I thereby deenergizing the audible signal devices I! and I8. In this latter position of the circuit breaker 40, a circuit is closed through circuit breaker contacts 42 which energize a visual signal device including a pilot light 43 which indicates that one of the manually operable circuit breakers connected with one of the alarm signals has been manually operated to the "oil" position for the audible signal devices. With such an arrangement, the audible signal devices are capable of being operated in response to any undesirable condition which might occur in the machine and which is provided with an alarm indicating circuit breaker system, and the operation of the audible signal in response to the presence of one undesirable condition is not affected by and is independent of the presence of another undesirable condition if the manually operable circuit breaker in the alarm system is placed in the horn-off position after the operation of one of the alarms has been determined. Furthermore', the presence of the particular undesirable condition remains indicated by the pilot light in the alarm system as long as the undesirable condition continues to exist. In the alarm system described above, the visual signal indicating pilot light 31 will be extinguished after the water in the machine housing has been removed, as the circuit breaker 35 then will be opened and the circuit breaker operating coil 26 again will be energized, so as to open the circuit between the circuit breaker contacts 38. When the undesirable condition has been corrected, the manually operable circuit breaker 40 must be returned to the position shown in the drawing with the circuit breaker contacts 4| and 42 in open circuit relationship in order to place the audible signal devices H and I8 again in circuit with the circuit breaker contacts 24 responsive to the operation of the circuit breaker operating coil 26.

In the drawing, I have shown a second alarm circuit breaker operable in response to the gas pressure within the dynamo-electric machine l0 and provided with a contactor 44 arranged to complete a circuit with circuit breaker contacts 45 or 46 if the ventilating gas pressure within the machine is lower or higher, respectively, than predetermined safe operating values. If the circuit breaker contactor 44 is operated to close a circuit with the circuit breaker contacts 45 or 46, the circuit breaker operating coil 21 is shunted, and thereby deenergized, resulting in the opening of the circuit between the circuit breaker contacts 25. This deenergizes the audible signal circuit breaker operating coil 23 and closes the circuit breakers 20 and 2|, thereby providing an audible signal by horns I! and l8, indicating the presence of an undesirable condition in the system. This deenergization of the circuit breaker operating coil 21 also closes an electric circuit through circuit breaker contacts 41 by a circuit breaker contactor 48 and energizes a visual signal device including a pilot light 49 which indicates the nature of the particular undesirable condition to be the presence of an undesirable pressure within the dynamoelectric machine 10. As in the other alarm system. the operator may turn of! the audible signal by operation of a circuit breaker 54 to its horn-off position, thereby closing a circuit through circuit breaker contacts 5i again to energize the audible signal circuit breaker opcrating coil 23 and open the circuit breakers 20 and 2| to prevent further operation of the horns l1 and I8. In this latter position of the manually operable circuit breaker 50, circuit breaker contacts 52 are closed and thereby energize the visual signal device pilot light 43, which indicates that one of the manually operable alarm circuit breakers is in the horn-off position. This provides for the operation of the audible signal de-' vice in response to the presence of other undesirable conditions associated with the dynamoelectric machine l irrespective of the-condition of the ventilating medium pressure in the machine.

It has been found desirable to indicate the deenergization of the direct current source of electric power supply by a signal other than the single visualsignal pilot light l6, and this condition is indicated by the deenergization of the horn circuit breaker operating coil 23 which completes the energizing circuit of the alternating current audible signal device l1 through the circuit breaker and provides an audible signal. The horn l1 may be turned off by opening the circuit breaker l9 until the direct current source of electric power supply I2 is reenergized. The reenergization of the direct current source of electric power supply is indicated by the visual signal light It and results in the reenergization of the alarm circuit breaker operating coils 26 and 21 and the audible signal circuit breaker operating coil 23, thereby placing the system again in condition for giving indications by all the signal devices. Thus, I have provided an alarm system which will indicate by an audible signal the presence of any undesirable condition associated with a dynamo-electric machine to whichthe system is applied irrespective of the presence of any other undesirable condition associated with the system, and a visual signal to indicate the particular nature of the undesirable condition for which the alarm signal is iven.

A test switch 53 is provided connected in series with the direct current source of power supply and the signal circuit breaker operating coils 26 and 21 for testing the operation of the alarm signal devices and circuit breakers. Opening the switch 53 deenergizes the circuit breaker operating coils 23, 26, and 21, and the various audible and visual signal devices l1, i8, 31, and

49 are energized. By closing the test switch 53. all of the circuit breaker coils 23, 26, and 21 are reenergized and the signal devices l1, I8, 31, and 49 are deenergized.

While I have illustrated and described a particular embodiment of my invention, modifications thereof will occur to those skilled in the art. I desire it to be understood, therefore, that my invention is not to be limited to the particular arrangement disclosed. and I intend in the a pended claims to cover all modifications which do not depart from the spirit and scope of my, invention.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. In a supervisory alarm system, a device to be supervised, circuit closing means operable by said device, a first source of electric power supply, a second source of electric power supply, a relay having a winding connected in circuit with said first source of electric power supply and having circuit closing contacts, a second rei lay having a winding connected in circuit with said second source of electric power supply and be supervised, a circuit closing means operable to closed circuit position in response to a predetermined condition of said device, a first source of electric power supply, a' second source of elec tric power supply, a first circuit breaker means having a winding connected in circuit with said first source of electric power supply, a second circuit breaker means having a winding connected in circuit with said second source of electric power supply, shunting means for said winding of said second circuit breaker means including said circuit closing means, a third circuit breaker means having a winding connected in series in a normally closed circuit through said first and second circuit breaker means, and two audible signal devices each connected to a different one of said two sources of electric power supply through said third circuit breaker means.

3. In a supervisory alarm system, a device to be supervised, a first source of electric power supply, a second source of electric power supply, a first circuit breaker means having a control winding connected in circuit with said first source of electric power supply, a second circuit breaker means having a control winding connected in circuit with said second source of electric power supply, a plurality of circuit closing means operable to closed circuit position in response to predetermined conditions of said device for shunting and deenergizing said winding of said .second circuit breaker means, a third circuit breaker means having normally open circuit 4. In a supervisory alarm system, a device to be supervised, a first source of electric power supply, a secondsource of electric power supply, a first circuit breaker means having a control winding connected in circuit with said first source of electric power supply, a second circuit breaker means having a. control winding connected in circuit with said second source or electric power supply, a plurality of circuit closing means operable to closed circuit position in response to predetermined conditions of said device for shunting and deenergizing said control winding of said second circuit breaker means, a third circuit breaker means having normally open circuit breaker contacts and a winding connected in series in a normally closed circuit through said first and second circuit breaker means, two audible signal device's each connected to a different one of said two sources of electric power supply through said third circuit breaker contacts, a visual signal device, and means for connecting said visual signal device to one of said sources of electric power supply through said second 'circult breaker means on deenergization of said second circuit breaker control winding.

5. In a supervisory alarm system, a device .to be supervised, a first source of electric power supply, a second source of electric power supply,

i a first circuit breaker mean having a control winding connected in circuit with said first source of electric power supply, a second circuit breaker means having a control winding connected in circuit with said second source of electric power supply, a circuit closing means operable to closed circuit position in response to a predetermined condition of said device for shunting and deer:- ergizing a winding of said second circuit breaker means, two audible signal devices, means including a third circuit breaker having a control winding connected in series with said first circuit breaker means and said second circuit breaker means in a normally closed circuit for connecting each of said audible signal devices .to a different one of said two sources of electric power supply for operation of one of said audible signal devices by one of said sources of electric power supply on deenergization of the other of said sources of electric power supply and for operation in response to said predetermined condition of said device, a visual signal device, means for connecting said visual signal device to one of said sources of electric power supply through said second circuit breaker means on deenergization of said control winding of said second circuit breaker means, and means in circuit across said second circuit breaker means for deenergizing said au-.

dlble signal devices independently of the condition of said circuit closing means and independently of said visual signal device.

6. In a supervisory alarm system, a device to be supervised, a first source of electric power supply, a second source of electric power supply, a first circuit breaker means having a control winding connected in circuit with said first source or electric power supply, a second circuit breaker means having a control winding connected in circuit with said second source of electric power supply, a circuit closing means operable to closed circuit position in response to a predetermined condition of said device' for shunting and deenergizing a winding of said second circuit breaker means, a third circuit breaker means having normally open circuit breaker contacts and a winding connected in series in a normally closed circuit through said first and second circuit breaker means, two audible signal devices each connected to a different one of said two sources of electric power supply through said third circuit breaker contacts for operation or one or said audible s18- nal devices by one of said sources of electric power supply on deenergizatlon of the other of said sources of electric power supply and for operation in response to said predetermined condition of said device, a visual signal device, means for connecting said visual signal device to one or said sources of electric power supply through said second circuit breaker means on deenergization of said control winding of said second circuit breaker means, and means in circuit across said second circuit breaker means for closing the circuit of said third circuit breaker means winding across said second circuit breaker means independently of the condition of said circuit closing means and independently of said visual signal device.

7. In a supervisory alarm system, a device to be supervised, a first source of electric power-sup- P y. a second source of lectric power supply, a first circuit breaker means having a control winding connected in circuit with said first source of electric power supply, a plurality of second circuit breaker means each having a control winding connected in circuit with said second source of electric power supply, a plurality of circuit closing means'each operable to closed circuit position in response to a difierent predetermined condition of said device for shunting and deer:- ergizing a winding of a diiferent one of said second circuit breaker means, a third circuit breaker means having normally open circuit breaker contacts and a winding connected in series in a normally closed circuit through said first and second circuit breaker means, two audible signal devices each connected to a different one of said two sources of electric power supply through said third circuit breaker contacts for operation of one of said audible signal devices by one of said sources of electric power supply on deenergization of the other of said sources of electric power supply and for operation in response to said predetermined conditions of said device, a plurality of visual signal devices, means for connecting each of said visual signal devices to one of said sources of electric power supply through one of said second circuit breaker means on deenergization of said control winding of said latter second circuit breaker means, and means in circuit across each of said second circuit breaker means for closing the circuit or said third circuit breaker means winding across said latter second circuit breaker means independently of the condition of other of said circuit closing means.

FRANK T. HORAN.

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