US2503598A - Polyphase sequence indicator - Google Patents

Description

April l1, 1950 l.. l.. slMKlNs PoLYPHAsE SEQUENCE INDICATOR Filed May 1o, 1946' -INVEN TOR.

l Irrrrrzvbrr v PHAE 5E Patented Apr. 11, 1950 POLYPHASE SEQUENCE INDICATOR Leon L. Simkins, Kalamazoo, Mich., assignor to The Wigginton Company, Kalamazoo, Mich.

Application May '10, 1946, 'Serial No. 668,834

7 Claims- The main objects lof this invention are:

First, to provide an electrical phase sequence indicating instrument usable though a wide 'range of voltages.

Second, to provide an electrical phase sequence indicating instrument of the mechanical type which does not require continuously rotating parts.

Third, to provide an electrical phase sequence indicating yinstrument with linkage for maintaining the instrument in neutral position when not in use.

Other objects and advantages of this invention will be -apparent yfrom a consideration of the following description and the accompanying drawings of ywhich there is one sheet and in which:

Fig. 1 represents a perspective view of a commercial embodiment of the invention.

Fig. 2 represents a plan view `of the mechanism of the instrument with the case removed.

Fig. 3 represents a vertical cross-sectional view taken along the plane indicated by the line 3--3 in Fig. 1 yand looking in the direction of the arrows.

Fig. 4 represents a schematic wiring diagram of the instrument.

Fig. 15 represents a horizontal vcross-sectional view taken along a plan indicated by the line 5-5 in Fig. 3 and looking in the direction of the arrows.

It has previouslybeen proposed to make instruments for indicating the phase rotation of 'polyphase electrical circuits employing lamp indicators or mechanical rotating mechanisms which were in fact small electric motors. 'This invention provides a simplified instrument of the mechanical indicating type.

'Indicated by the reference character Il) is the testinstrument whichis provided with vtest'leads I2, I4, and I6, each of which has a spring clamp I8 connected to the end thereof. 'The connections between the leads and the spring clamps .are covered with insulating sleeves 2t which it is preferred to make of different colored rubber to correspond to the connections of the leads vwithin the instrument as indicated on the face of the instrument. The leads are enclosed by a iiexible conduit 22 through a portion of their length and enter the case l0 through a tiexible grommet '24.

With reference to Figs. 3 and 5, it vwill be noted that the case IU consists of a box 26 one side of which defines an aperture through vwhich the -grommet 24extends and a cover 28. The cover is arranged to be secured tothe box vby means 2 ofthe four lscrews v3l! passed through the corners of the cover.

Secured to the inner side of the cover 28 by means of the screws 32 and spaced therefrom by means of the sleeves 34 is a plate 36 with a backwardly bent flange 38. 'The plate 36 vserves `as :asupport for the U-shaped spring clip 4B which `is secured thereto by means of the bolt 42. The bolt 42 extends through the'plate and also serves to secure lboth leaves of a spring switch 44 to the forward side of the plate.

Removably vretained in the spring clip 40 are the two cylindricalcondensers llt which are electrically connected 2in lparallel at one end to the switch 44 by means of the conductor 48, and vat the other end by means of the conductor 50 to ya contact common to each of two coils.

Secured to the upper side of the flange 38 and having va -do-wnwardly bent portion is the coil support member 52. The support member 52 extends downwardly to adjacent the lower edge of the box and is there bent into a U-shaped portion 54. The pin 56 passing' through both legs ofthe U-shaped portion 54 secures the lower end of the coil support member to the lower vend ofthe cover 28. The support 52 is further provided as indicated in Fig. 2 with laterally extended ear sections 58 through which the screws 60 are passed to support the lower ends of a pair of coils l2. The upper ends of the coils 62 yare ysecured in place bymeans of pins projecting into the under side ofthe flange 38 on the upperrsupport 36.

A U-shaped indicator 64 is pivotally mounted on the pin 56 and is provided with a pointer section B6, laterally extending arms 68 and an upwardly extending arm 'l0 in the cen-ter thereof. The arms 58 are connected by means of the pins 'H to the 'lower ends of armature members 12 positioned vertically within-the coils v(i2. `A vertically extending coil spring 1li is yconnected'between theupright arm 'iii and the flange '38 of the lupper support member. The indicator may thus rotate about the .pin 5B in response tomov'ement of either of the armatures l2 but will lbe returned to a neutral position upon de-energization of the coils by action of the coil :spring "It on the arm.

The cover 28 is piercedby two openings, 16 and 18, which may be provided with window closures 80. Aplate '3| on which operating instruction-s and voltage capacity may bo printed as shown in Fig. l operates to hold the windows inplace. The cover is also provided with a test button .82 which is larranged to close the contacts of the 3 switch 44. It will be noted that the pointer B6 extends upwardly within the instrument to where it may be viewed through the windows 80 when the instrument is in operation.

The electrical connections within the instrument are most clearly indicated in Fig. 4 which shows that one of the leads, such as I2, is connected to one end of one of the coils 82 while another of the leads I6 is connected to the end of the other coil 62. The opposite ends of the coils 62 are joined together and connected to one side of the condensers 46 by the conductor 5I) as was explained before.

'I'he remaining lead I4 is connected to the free terminal of the switch 44 so that it may be connected through the switch to the other side of the condenser. The armatures 'I2 are slidably positioned within the coils 62 and are arranged to be attracted or pulled upwardly by the passage of current through the coils.

From theabove description it should be apparent to anyone skilled in the art that if the leads I2, I4, and I6 are connected to a threephase electrical system no indication will be shown by the pointer B6 until the button BIJl is pressed to close the switch 44. Until that takes place current will flow equally through both the coils 62 and pressure on the arms 68 by the armatures 'I2 will be balanced. However, on closing the switch 44 current will ow through the condenser 42 which will have a leading characteristic with respect to the currents flowing through the conductors I2 and IB. This will cause an unbalance of the current through the coils 62 and one 0f the armatures I2 will be attracted morev strongly than the other. This will rotate the indicator 64 against the tension of the spring 14 and cause the pointer 66 to appear through one of the windows 'I6 or 18. If the leads I2, I4 and I6 are connected to the circuit being tested corresponding to the phase sequence indications printed on the plate 8|, the phase rotation of the current in the three conductors will be accurately indicated by the pointer 66. The instructions on the plate 8| are arranged to agree with the internal connections in the instrument. Thus when the red lead I2 is connected to the top wire of three horizontal wires or the left wire of three vertical wires being tested and the black lead is connected to the bottom or right wire of the three wires as the notations over the windows 'I6 and 'I8 direct, the left coil 62 in Fig. 4 will be energized from the red lead and the right coil will be energized from the black lead. The condenser will be energized from the center wire and the white lead when the switch 44 is closed. Since the summation of all currents passing through the common point of the condenser and coil circuits is zero in a substantially balanced circuit, the leading character of the current in the condenser circuit and white lead I4 causes the unbalance between the two coil circuits which results in actuation of the pointer. A complete description and vectorial diagrams showing the relationship of the currents in a Y connected phase indicator is set out in the patent to A. R.

Hand No. 2,027,864, issued January 14, 1936. In

all cases, the conductor to which the red lead is attached is considered as the iirst conductor and the conductor to which the black lead is attached is considered as the third conductor. Then when the pointer 66 appears behind the window I6 the instrument indicates that the phase rotation in the three conductors being tested is 1, 2, 3 and when the pointer appears behind the right window 'I8 the phase rotation of the circuit is 3, 2, 1 as shown by the indicia underneath the windows.

The meter will operate at any voltage within the capacity of the wiring since its operation depends on the unbalance of current in the two coils and is not limited to critical voltage such as is the case when lamps are used. The indication is positive and there is no need to judge between the brightness of two lamps.

My invention has been illustrated and described in a highly practical embodiment thereof. I have not attempted to illustrate or describe further adaptations of the invention, as it is believed this disclosure will enable those skilled in the art to embody or adapt the invention as may be desired.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. An electrical phase sequence indicating instrument comprising a pair of coils and a condenser continuously electrically connected in Y and adapted to have the branches of the Y directly connected to a three-phase power source, a switch in series with said condenser, armatures within said coils, and a movable pointer member, said armatures being opposingly connected to said pointer to effect movement thereof by unbalance between the pull on said armatures.

2. An electrical phase sequence indicating instrument comprising a pair of coils and a condenser continuously electrically connected in Y and adapted to have the branches of the Y directly connected to a three-phase power source, a switch in series with said condenser, armatures within said coils, and a pivoted pointer member, said armatures being connected to equal lever arms of said pointer.

S. An electrical phase sequence indicating instrument comprising a pair of coils and a condenser continuously electrically connected in Y and adapted to have the branches of the Y directly connected to a three-phase power source, a switch in series with said condenser, a pivotally mounted indicator, armatures associated with said coils and connected to said indicator with equal and opposite lever arms with regard to said pivot, and spring means arranged to bias said indicator to a neutral position.

4. An electrical phase sequence indicating instrument comprising a pair of coils and a condenser connected in Y and adapted to have the branches of the Y directly connected to a threephase power source, a switch in series with said condenser, an indicator, a pivot for said indicator, armatures associated with said coils and connected to said indicator with equal lever arms with regard to said pivot, and tension spring means connected between said indicator and a fixed portion of said instrument and radially disposed with respect to said pivot.

5. An electrical phase sequence indicating instrument comprising a box, a cover, an upper support member secured to said cover, a condenser and a switch secured to said upper support member and electrically connected in series, a lower support member having a U-shaped lower end, a pin connecting said U-shaped end to said cover and extending between the arms of said U-shaped end, an indicator having a U-shaped end with its arms pivotally mounted on said pin, a pair of coils secured to said lower support and electrically connected in Y with said condenser, armatures associated with said coils and con- 5 nected to said indicator on opposite sides of said pin and a tension spring connected between one arm of the U-shaped end of said indicator and said upper support and extending radially from said pin.

6. An electrical phase sequence indicating in` strument comprising a pair of coils and a noninductive impedance connected in Y and adapted to have the branches of the Y directly connected yto a three-phase power source, a switch connected in series to said impedance, said coils having a continuous electrical connection, armatures Within said coils, a pointer member, said armatures being connected to equal lever arms on said pointer, and test leads adapted to be connected to a circuit to be tested and connected to the free ends of said coils and impedance and series switch.

7. An electrical phase sequence indicating instrument comprising a pair of coils and a noninductive impedance connected in Y and adapted 6 to have the branches of the Y directly connected to a three-phase power source, said coils having a continuous electrical connection, armatures within said coils and a pointer member, said armatures being connected to lever arms on said pointer.

LEON L. SIMKINS.

REFERENCES CTED The following references are of record in the file of this patent:

UNITED STATES PATENTS

Images