Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H73/00—Protective overload circuit-breaking switches in which excess current opens the contacts by automatic release of mechanical energy stored by previous operation of a hand reset mechanism
  • H01H73/02—Details
  • H01H73/12—Means for indicating condition of the switch
  • H01H73/14—Indicating lamp structurally associated with the switch
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
  • H01H71/00—Details of the protective switches or relays covered by groups H01H73/00 - H01H83/00
  • H01H71/04—Means for indicating condition of the switching device

Definitions

• TITLE I. INDICATOR FOR BLOWN CIRCUIT BREAKER II. TECHNICAL FIELD
• the present invention relates to circuit breakers and more specifically to means of indicating that a circuit breaker has blown.
• conventional circuit breakers are placed in banks of several side by side units, with each circuit breaker having an operating handle extending outward from the front of the casing of the circuit breaker. Normally, the handle has two extreme positions, an "On" position in which the circuit breaker completes the circuit, and another extreme position or “Off” position, in which the circuit is interrupted or opened. When this load circuit is overloaded, it will “blow", or more specifically, the load circuit is interrupted by a circuit overload response member.
• the present invention is directed to a blown circuit indicator to be used in combination with a conventional circuit breaker.
• the conventional circuit breaker load circuit normally comprises first switch means for opening or closing the load circuit, and a tripping means for triggering the first switch means to interrupt the load circuit in response to an overload condition of the load circuit.
• the problem found with conventional circuit breakers, including the device described and claimed by this inventor in U. S. patent number 4,056,816, is that when a light indicator is used there is a small current flowing through the light indicator circuit, which is in parallel with the load circuit, and through the load. refers- to the circuitry outside the circuit breaker that is being fed.
• “Load circuit” refers to the circuit inside the circuit breaker comprising a first switch means and a tripping means) .
• the improvement of the present invention comprises a blown breaker indicator circuit having a second switch means and a connection to a third neutral contact thereby eliminating the above mentioned flow of current through the load. It is a primary object of the present invention to provide a light indicator for a conventional circuit breaker that can be used safely to facilitate the locating of a circuit breaker that has blown.
• a further object of the present invention is ' to provide a light indicator for a conventional circuit breaker, which will activate a light emitting diode in the front panel of the breaker casing, so that there will be visible indication that a particular circuit breaker has blown.
• a related object of the present invention is to provide another embodiment of the present invention in which a light emitting diode is deactivated so as to visually indicate that a particular curcuit breaker has blown.
• Yet another object of the present invention is to provide an indicating light in the front' panel of the circuit breaker which is either activated or deactivated and stays in such a condition until the blown breaker has been reset, presumably after the cause of the overload on the circuit has been corrected.
• FIG. 1 is an elevation view of the second embodiment of the present invention having the conventional bimetallic circuit breaker to which the blown breaker indicator circuit of this invention has been added, with the circuit breaker being "on", the face or cover of the casing being omitted.
• FIG. 2 is an elevation view of the embodiment shown in FIG. 1, with the circuit breaker being "blown”.
• FIG. 3 is an elevation view of the first embodiment of the present invention having the conventional bimetallic circuit breaker to which the blown breaker indicator circuit of this invention has been added, the circuit breaker being "on”.
• FIG. 1 is an elevation view of the second embodiment of the present invention having the conventional bimetallic circuit breaker to which the blown breaker indicator circuit of this invention has been added, with the circuit breaker being "on".
• FIG. 4 is an elevation view of the embodiment of FIG. 3 with the circuit breaker being "blown".
• FIG. 5 is a schematic diagram of the first embodiment of the present invention shown in FIG. 4.
• FIG. 6 is a schematic diagram of the second embodiment of the present invention of FIG. 2.
• FIG. 7 is a diagramical view of the circuit breaker of the present invention interconnected with the load of a power system. VI. BEST MODE OF CARRYING OUT THE INVENTION
• a conventional blown circuit breaker, generally indicated as 9, is shown having a housing or case 10 suitable insulating material and in which the side cover or face is omitted from the illustration to enable the interior, parts to be illustrated.
• the case and cover are typically of molded insulating plastic.
• the various elements of a conventional circuit breaker mechanism, and also the elements of this invention, are mounted with the case 10.
• the case 10 has a front panel 12 through which an operating handle 13 extends.
• the handle 13 In FIG. 1 the handle 13 is shown in load circuit "ON" position 14 and in dotted outline, the handle 13 is shown in "OFF" position 15.
• the handle 13 In FIG. 2 the handle 13 is shown in its "blown” position 17.
• the circuit breaker 9 has first and second line terminals 18 and 34 which electrically connect the breaker 9 to the load to be protected.
• a load circuit 8 including first switch means 25 is electrically connected at one end to line terminal 18 and at the other end to line terminal 34.
• the first line terminal 18 provides ideally a fixed contact 16 mounted in the casing 10 to engage a main bus bar 19 when the circuit breaker is inserted into a distribution panel (not shown) .
• a lever 22 having a movable contact 20 is shown in its circuit completing position 21 and in dotted outline, its open posi- tion 23.
• the first switch means 25 is defined to include the first line terminal 18 and lever 22 which forms a circuit interrupting switch.
• the specific structural design of first switch means 25 is of conventional design and can take many different forms.
• the conventional circuit breaker 9 is of the type which is normally provided with overload tripping means 31 having a trip arm 24 pivoted on a boss 26 secured to the case 10, whereby the arm 24 is pivoted between a set position 27 shown in FIG. 1 and a tripped position 29 shown in FIG. 2.
• An overcenter tension spring 28 has one end connected to the lever 22 and the other end connected to the trip arm 24.
• the handle 13, lever 22 and spring 28 form an over- center arrangement, or toggle, and urges the movable contact 20 towards the fixed contact 16 when the spring 28 is on one side of the pivot point 30 shown in FIG. 1 and urges the movable contact 20 to the open position when the spring 26 is on the other side at the pivot point 30, as shown in FIG. 2.
• the current responsive member of the overload tripping means 31 is a thermally responsive or bimetallic latching member 38 which retains said tripping means in its set position 27.
• the specific structural detail of the overload tripping means 31 is known to the art, and can take numerous forms when combined with the present invention.
• OMPI _. niIrPOu t 1 bar 35 is provided for connecting the circuit breaker 9 to the
• the load terminal connecting screw 32 defines
• the second line terminal 34 is preferably riveted or screwed
• thermostat element 5 is a generally hook shaped thermostat element of at least two layers
• the circuit breaker operates in the customary manner for
• 25 tripping means 31 would comprise primarily a magnetic coil with its
• light means 50 In the first embodiment of this invention, light means 50,
• the circuit breaker 9 has blown.
• the light means 50 will be deactivated when the circuit breaker is blown.
• the first embodiment is illustrated in FIGS. 3 and 4 and the second embodiment is illustrated in FIGS. 1 and 2.
• the light means 50 is positioned at the front of the casing 10 on front panel 12 so as to provide a visual indication of when the circuit has been blown.
• the blown breaker indicator circuit 33 includes in series a second switch means 57, resistor means 44 and light means 50.
• the blown breaker indicator circuit 33 » is electrically interconnected at one end to the third line terminal 37 which is a neutral line.
• the blown breaker indicator circuit 33 is electrically interconnected to the first line terminal 18.
• the first line terminal 18 is electrically connected to the main bus bar 19.
• the third line terminal 37 is electrically connected to the neutral.
• the first and second line terminal 18 and 34 connect with the load 49.
• the order of the second switch means 57, resistor means 44 and light means 50 in their series relationship can be changed as long as they are in series.
• Both the embodiment of FIG. 1 and the embodiment of FIG. 3 can be utilized in conventional DC or AC power systems, whether it is a single phase, two phase or three phase system. Likewise, it is immaterial whether the power system is having drawn therefrom 110 volts or 220 volts.
• the circuit breaker 9 is electrically inserted in series with the hot phase line 51 by first and second line terminals 18 and 34, as shown in FIG. 7.
• the blown breaker indicator circuit 33 is electrically coupled to a neutral or ground 55 of the power distribution system so as not to be in series with load 49.
• the above illustrated examples of conventional power systems is provided merely to emphasize the fact that the present breaker 9 with the associated invention can be incorporated into any conventional power system.
• the circuit 33 would be interconnected with the phase line 51 at a point intermediate to the power supply 53 and the first switch means 25.
• the thermal responsive member 38 in both embodiments of the present invention as shown in FIG. 1 and FIG. 3, there is provided the thermal responsive member 38, prefer- ably in the form of a bimetal strip which is mechanically linked to second switch means 57. In a conventional manner when the current exceeds a predetermined or dangerous rate, the thermal responsive member 38 will activate second switch means 57 substantially at the same time that the first switch means 25 is opened.
• the thermal responsive member 38 is shown in its non- activated position 45 and its activated position 47, as shown in FIGS. 1 and 2.
• the excessive current in load circuit 8 exceeds the predetermined danger value
• the excessive heat thereby generated triggers the thermal responsive member 38 from its non-activated position 45 to its activated position 47.
• the movement of the thermal responsive element 38 creates a corresponding movement with second switch means 57 so as to open or close the blown breaker indicator circuit 33, depending upon the embodiment.
• the light means 50 will be initially "off” with the first switch means 25 closed, thereby defining a completed load circuit 8.
• second switch means 57 is pulled into circuit completing relationship with the blown breaker indicator circuit 33.
• second switch means 57 comprises a curvilinear contact wire 58 disposed in spaced apart relationship to an elbow shaped prong 59. This elbow shaped prong 59 is an extension of 24.
• the light means 50 will be initially “on” or activated with first switch means 25 disposed in circuit completing relationship to the load circuit 8. Subsequently, light means 50 will be "off” or deactivated when first switch means 25 is disposed in circuit interrupting relationship wLth the load circuit 8 as shown in FIG. 2. In other words, the light means 50 will be deactivated or ⁇ off" when an overload to the load circuit 8 occurs.
• This particular breaker design has practical utilization when a plurality of breakers 9 are incorporated into a single distribution panel.
• this embodiment differs structurally from the other embodiment in ' that as thermal responsive member 38 bends to its activated position 47, the second switch means 57 is pulled forward so as to be disposed in circuit interrupting relationship to the blown breaker indicator circuit 33.
• second switch means 57 has its curvilinear wire 58 disposed in electrical engagement with its elbow shaped wire prong 60 when the trip arm is not released, as shown inJ-IG. 1.
• the curvilinear wire 58 is in spaced-apart relationship to the wire prong 60 as shown in FIG. 2.
• FIG. 7 The simplified schematic of the circuitry involved in both embodiments of the present invention is presented in FIG. 7. From the simplified schematic, it can be seen that unlike some of the prior art devices, the blown breaker indicator circuit 33 is not in parallel with first switch means 25. More specifically, by electrically interconnecting the blown breaker indicator circuit to a neutral or ground, the load, identified and represented by reference number 49, is free of any current flow when the first switch means 25 is open. This meets certain industrial requirements that. there be no current flow through the load circuit 8, no matter how small, when the breaker 9 has been tripped or blown.
• the handle 13 operates first switch means 25 which includes lever 22 to make or break the load circuit 8 through contact 16 and movable contact 22 in the normal manner.
• the overload of load circuit 8 causes trip arm 24 to change the state of second switch means 57, or more specifically, to either open or close second switch means 57.
• second switch means 57 is opened or closed, the light means 50 is deactivated or activated respectively. In either case, the change of the light means 50 from its normal on-off state will provide a blown breaker signal indicating that the circuit breaker 9 has been blown.

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• Breakers (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=25357560

Family Applications (1)

Country Status (3)

Family Cites Families (7)

• 1978
  • 1978-04-28 JP JP5017978A patent/JPS54103572A/ja active Pending
• 1979
  • 1979-01-11 WO PCT/US1979/000014 patent/WO1979000537A1/en unknown
  • 1979-08-13 EP EP19790900529 patent/EP0008583A1/de not_active Withdrawn

Non-Patent Citations (1)

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