US1730283A - Control system - Google Patents

Description

P- MCSHANE CONTROL SYSTEM Oct 1929.

Filed Sept. 19, 1927 F rward 5 a 6 l5 /6 3 I50 I51, Forward Fan/arse L 7 I70 LA Forward Fever 7a Fig. 1.

INVENTOR Phelan M0 Shane,

ATTORINEY Patented Oct. 1, 1929 UNITED STATES PATENT OFFICE i PHELAN ICSHANE, OF PITTSBOBGH, PENNSYIlVANIA, ASSIGNOB T WESTINGHOUSE ELECTRIC & IANUIAO'1'UBING COMPANY, A CORPORATION OF PENNSYLVANIA com'nor. sYs'rEu a lication m September s, 1927. Serial No. 220,562.

My invention relates to improvements in control s stems and. particularly to control systems or a main controller actuated from liable in operation.

remote control stations. v

The object of my invention, generally stated, is to provide a remote control'system,

which will be simpleinjconstruction and re- It is also an object-of invention to provide for operating a" plurality of magneticdevices froma numberpof distant control stations by means of a-single controlconductor apparent w en the description set forth here-' inafteristaken in connectionwi'th the accompanying drawing, wherein; a

Figure 1 is a simplified schematic diagram of a control system connected in accordance with this invention, and

Fig. 2 is a diagrammatic view of the control system shown in Figure 1 adapted for controlling-the 0 ration of a reversible motor. While the invention may be utilized for many purposes it may be illustrated to advantage in connection with-a system for controlling the operation of the'motor 1 illus.- tratedin Fig.2. To simplify the following if ll'ts'illstted'th desq'np e emen' u m m e remote control switches such as 150 is thrown schematic diagram of Fig. 1 andthose illustrated in Fig. 2. which are similar are noted by the same indicating numerals; The control circuits foroperating the. various mechanisms in the two figures bingidentical they :51 be either positive of negative depending may be more easily tracedby consideringFi g.

1inconnection withFig.2; p The motor'l beinga series type direct-f current motor, thev reversal of the same can be accomplished by simply reversing the di-' rection of current flowing through the arma--- ture and to -accomplish this reversal, two pairs of a well known construction, having actuattheir actuatin co of reversing contactors 2 and 311ml 4 and 5:-

ilngefioils 2a, 3a, 4a and 5a, respectively, are uti- The motor 1 may beconnected to any source of supply which in this case is the line con ductors 6 and 7 as illustrated in Fig. 2. A switch 8 is rovided for closing a-circuit which exten s from the line conductor 7, through actuating coil9a of the overload relay 9, the interlock on contactor 10, and assuming the reversing contactors 2 and 4 are closed, contactor 2, armature 1aof the motor 1, contactor 4, the series field winding 13, to

the positive line conductor 6. If the motor reversing contactors 3 and 5 are'closed instead of the reversing " contactors 2 and 4, the

circuitleading'through' the armature will be by way'of contactor 5, through the armature 1a ina direction opposite to that previously traced. through thecontactor 3, the series field winding 13 to the positive line conductor :6, and the motor 1 will operate the opposite direction.

tors as desired from any number of remote control stations, such as 15, 16, and 17, the system illustrated in both Figs. 1 and'2 is ro- In order to actuate the reversing contacvided. The remotecontrol stations are il ustrated by single pole switches '15a, 16a'and 17a connected to a single conductor orcollectorv rail 18 and disposed to make contact with a pair of contact points 15b and 15a, 16b and 160, 17 band 17 a, respectively, which are connected to the positive and negative sides of the line conductors 6 and 7 respectively. It will be seen, therefore, that when one of the into engagement with one or the other of the e impressed upon the single conductor 18 -uponwhether-it is connected to the positive line conductor 6 ductor 7 v In the controller proper there is provided a pair of selector contactors 21 and 22 which are double acting tivspes of contactors and have or the negativeline con rectly across t e source of supply that is the positive and negativeconductors 24 and 25,

' 21a and-22a connected di-.

respectively; To control the action of the selector contactors 21 and 22, a single control conductor 19 is connected to a point20 midway between the actuating coil 21a and 22a. When there is no voltage impressed upon the 7 single control conductor 19, the two actuating coils 21a and 22a of the selector contactors will be energized and the contactors closed, sin'cethey are connected in series relation across the conductors 24 and 25 leading. from the source of supply. When the control conductor 19becomes energized by actuating any one of the switches 15, 16 and 17 to its closed position, a shunting circuit connecting the point20, between coils 21a and 22a, is completed. -It will be readily understood that one of the coils 21aor22a will 'become'deenergized, depending upon which power conductor is connected to the single control conductor 19 upon the operation of any one of the switches 15, 16 and 17'.

The two selector contactors 21 and 22 in turn control the operation of the main connetic contactor 28. When contactor 21 is I energized and held open, a circuit is established which may be traced from conductor 26, interlock 21b andthe actuating coil 29a of a magnetic contactor 29'. When contactor 22 is energized and held open, a circuit is established through conductor 27, interlock 22b "and the actuatingcoil 30a of magnetic contactor 30. The contactors 28, 29 and 30 together with a low voltagerelay 31 are provided for controlling the operation of the reversing switches 2 and 4, and 3 and 5, and the motor line contactor 10 since these contactors are in circuit relation with the actuating coils of the relays and contactors 28, 29

- and 30. The actuating coil 31a of the low voltage relay 31 may be energized through two paths, one through the interlocks 29b and 30?) on the magnetic contactor 29 and 30 and the coil 31a while the other which is a holding circuit is through the interlock 31b andthe actuating coil 31a. The first circuit or actuating circuit as will be seen byreference to Fig. 1 or 2 can be completed'only when contactors 29 and 30 are closed simultaneously.

The motor 1 may be connected to the power source through a line contactor 10 which may be closedfwhen the low voltage'relay 31 and the magnetic contactor 28 are closed. The

circuit to the actuating coil 10a of the linecontactor 10 being through the iiiterlocks 31b of the low voltage relay 31, the interlock 28?) on the; contactor 28 and the actuating coil ,10a. T e actuating coils of the reversingcontactors 2 and 4, and 3 and 5 are energized whenthe two interlocks 31b, 28b and the interlock 29c and 300 are closed.

Upon closing the knife switch23 when no voltage is impressed upon the conductor 19, the actuating coils 21a and 22a of the selector contactors 21 and 22 will be energized and the contactors 21 and 22 actuated to their upper positions, as viewed in Fig. 2 of the drawing, to bridge contact members 216 and 22b re spectively. The closure of contactors 21 and 22 upon the energizing of the actuating coils 21a and 22a closes the circuit traced.hereinbefore through the actuating coils 29a and 30a. of the contactors 29 and 30.

When the two coils 29a and 30a, respectively, have been energized, the contactors 29 and 30 are actuated to their closed position to establish a circuit which may be traced from the positive line conductor 24, through the in- , terlocks 29b and 30b of the contactor 29 and circuit will energize the actuating coil 31a of the low voltage relay31 and cause the same to close, thereby establishing a holding circuit which extends from'theline conductors 24, through the low voltage relay 31, the actuating coil 31a and the overload relay 9 to the negative line conductor 25.

When the contactors 29 and 30 ar'e clo-sed, the interlocks 29b and 30b and the interlocks 29c and 300 are closed. Assuming now that one of the control station switches 15, 16 or 17 has been actuated to a position to impress either-positive or negative line voltage upon the conductor 19, then one of the actuating coils 2111 or 22a will be deenergized aspreviously described. Therefore, one of the contractors 21 or 22 will fall open,'interrupting the circuit to one or the other of the actuating coils 29a or lock, 22c, and the actuating coil 28a of the contactor 28 to the negative line conductor 25. This will cause contactor 28 to close and energize coil 10a of the motor line contactor- 10 which is co'nnected'in a circuit that may be traced from the line conductor 24, low voltage relay 31, interlocks 28b and coil 10a to the negative line conductor-25. Therefore,'when the contactor 28 closes, the motor line contactor 10 will close.

I The contactor 30 being opened, when the coil 30a was detactor 30 closes as described hereinbefore, thereby establishing an operating circuit forate in the opposite direction; f It will be notedthat if the voltage to the.

'energized,and the contactor 29 remaining in the closed position, a circuit will be estab-' lished from positive line conductor 24 through the low voltage relay 31, contactor 28, the interlocks 29c the two actuating coils 2a and 4a associated with the reversing contactors-2 and 4, to the negative line con-I ductor 25. The circuit will actuate the reversing contactors 2 and 4. Therefore, the motor will start to operate in the direction corresponding to the current flowing through these two-contactors.

Assuming now that it is desired to reverse the operation of the motor, then one of the master switches 15, 16 or 17 will be thrown to change the polarity of the voltage impressed upon the line conductorl9. In this instance, the actuating coil 21a of contactor 21 becomes short circuited, and full line voltage is impressed upon coil 22a of contactor 22. Upon the closure of contactor 22, the conthe reversing contactors 3 and 5. This circuit may be traced from' line conductor 24, through relay 31, contactor 28, interlocks30a of contactor 30, conductor 32, and thence through'a parallel circuit comprising coils 3a and a, to the line conductor 25.

- The closure of the reversing contactors 3 and 5 thereby establishes a circuit extended through thearmature of the motor 11in a directionopposit-e to that when the other tw'o reversing contactors were closed. This will cause the motor 1 to reverse and oper- System should fail or fall below a predetermined amount, that the low voltage relay 31 will fall open, and the same can not be again closed until the circuit previously traced "through the interlocks 29b and b is established, which occurs only when all the master the machinery to avoid accidents.

' While I have illustrated and describeda particular embodiment of the invention, it is intended that all matter contained herein voltage preciate switches are their ofi positions. Thereby a lowflvoltage protection is provided to prevent the apparatus to which the controller is attached from starting up, after voltageis again restored to the line, unless the control switches themselves are first re turned to their neutral position. This low (protection can be very readily ap-.

'where a system incorporating the invention is applied to steel mill operation in which it "is necessary-at all times to exercise the greatest of care in the operation of shall be-interpreted as illustrative and not in a limiting sense, since manifestly the same may be considerably varied without depart ing from thev spirit oi the invention as set I claim as my invention:

ation of the motor, and a low-voltage relay disposed to render said main controller inoperativeinresponse to a redetermined volta e reduction, said relay Being dependent for its closure upon said governing means.

v 2; In a control system. in combination, a

main controller, a plurality of control sta tions for operating the controller, a single control conductor for connecting the control stations to the controller, said main controller being provided with a plurality of selecting switches for governing the, operation of the controller, said selecting switches being responsive to the energization of the control conductor, and i3, low-voltage relay disposed to render themain controller inoperative in response to a predetermined reduction in voltage, said low-voltage relay being dependent'for its closure upon said selecting switches.

3. In a motor-control system, combination, a motor, a ource of power for themotor, means for establishing a motor circuit, a plurality ofyreversing switches disposed to be operated in pairs, relays for controlling the energization of each pair of reversing switches, said relays being disposed to effect the operation oi the reversing switches when deenergized, manually oper-- able means for controlling the energization of the relays, a low-voltage relay for interrelay being dependent forits closure on sald relays.-

. 4, In a motor-control system, in combination, a motor, a source of power 'for the motor, means for establishing a motor circuit, reversing switches-for controlling the direction ofoperation of the motor, means for selectively operatin the reversing switches, a manually opera le switch for convrupting the motor circuit, said low-voltage trolling the operation of the means for 'selectively operating the reversing switches, a no-voltage relay for interru ting the motor circuit upon the failure 0 voltage,-said reversing switches beingresponsive to the opening ofv the no-voltage relay, said 'novoltage relay being dependent for its closure upon the means for selectively operating 1 the reversing switches, whereby, when the relay is opened,,upon the failure of vol e,

it cannotbe rec osed until themanu y operable switch is operated.

: tor, means 5. In a motor-control system, in combination, a motor a source of power for the mofor controlling the suplply of power to the motor, reversing switc es for controlling the direction of operation of the motor, means for selectively operating the reversing switches to operate the motor in a redetermined direction, a no-volta e relay or governing the means for control ing' the supply of power to the motor upon the failure of voltage, said relay controlling the operation of the reversing switches through I said selective means, said selective means being disposed for operation to efiect the setting of the relay in the closed position.

I 6. In a motor-control system, in combination, a motor, a source of power for the motor, reversing switches for controlling the direction of operation of the motor, a switch for controlling thesupply of current to the reversing switches, means cooperative with said control switch for; selecting and operating predeterminedreversing switches, anda low-voltage relay responsive to the voltage across'the source of supply disposed to control said switch,'said low-voltage relay being dependent, when it hasopened, on the selecting means for its closure. 5

' 7 In a motor-control system, in combination, a motor, a source-of-power for the motor, reversing switches .for controlling the direction of operation of-the motor, a switch for controlling the su'pply'of current to the reversing switches, means cooperative with said control switch for selecting and'operating predetermined reversing switches, a low-voltage relay responsive't'o the voltage across the source of supply disposed to control said switch, said low-voltage relay being dependent, when it has opened, on the selecting means for its closure and manual means for initiatingthe operationof the selecting means v 8. In a motor-control system, in combination, .a motor, a source of power for the motor, reversing switches for controlling the direction of operation of themotor, a switch for controlling the supply of current to the reversing swltches, means cooperative with a said control switch for selecting and operating predetermined reversing switches, a lowvoltage relay responsive to the voltage across the source ofgsupply disposed to control said switch, said low-voltage rela being dependent, when it has opened, on t e selecting means for its closure, a plurality ofmanual control stations for controlling the operation n of the selecting means, and a single control 7 conductor disposed to connect said manualcontrol stations to the selecting means. In testimony whereof, I have hereunto subscribed my name the 12th day of Sep tember,1927. PHEL N MG HANE.

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