Abstract:
An electrical energy diversion measurement device includes a first clip-on transformer for location about the power cable at high elevation in the zone of the weather guard or at underground manhole location where power supply enters the consumer&#39;s dwelling. A second clip-on transformer is simultaneously located about a cable passing through the watt power meter housing supplying power to the consumer. A digital measurement means is responsive to the current sensed by either the current transformers or simultaneously by the transformers and digitally displays the current of each or the difference between the sensed current as a representation of current difference and energy diversion.

Description:
RELATED APPLICATION 
     This application relates to the application being filed simultaneously herewith under the title &#34;Electrical Energy Diversion Metering&#34;, Ser. No. 469,934, 2-25-83, and the contents therein are incorporated by reference herein. 
     BACKGROUND OF THE INVENTION 
     This invention relates to a device and system for determining electrical energy diversion. In particular, the invention is for a device to detect the unauthorized connection of load to the power line supply from a utility to a consumer, ahead of the watt-hour meter. 
     Tampering with the supply of electrical power from a utility to a consumer is becoming an increasing problem. One manner of electricity theft in this fashion is for the consumer to tap off power from the power lines from the utility at a point ahead of the location of the watt-hour meter. Such tapped off power can be led by the consumer to operate air conditioners, swimming pool pumps and similar apparatus. Often such consumers incorporate a switch in the tapped off line so that when they suspect or are aware of a meter reader&#39;s visit to the home, such switch is used to isolate the illegally connected apparatus. Thus, if forewarned, the consumer usually has a simple facility for covering over his illegal use of electricity. 
     There is accordingly a need to have an electrical energy diversion detection device which relatively unsuspectingly and quickly can be located in position and used to detect illegally consumed electricity. Thereby the ease for the consumer to hide his illegal use is minimized. The applicant is unaware of any such device which is currently available. 
     SUMMARY OF THE INVENTION 
     There is provided an electrical energy diversion measurement device which comprises a first clip-on current transformer means for connection in relationship about an inlet power cable from the electric utility. There is also a second clip-on current transformer means for connection in relationship about an inlet power supply to the consumer. Current measuring means, preferably digital, is responsive to the current sensed simultaneously by both current transformer means thereby to obtain a differential measurement of energy which is displayed, preferably digitally, through the measuring means. 
     Where needed an adaptor is provided to replace a watt-hour meter in its housing, and the inlet power supply is provided through the adaptor by locating the clip-on transformer about a conductor in the adaptor means. The second clip-on transformer is located about the same current line coming from the utility distribution system to the consumer, in a relatively high zone near the weatherguard to the inlet power supply to the consumer&#39;s habitat, or as an alternate in a manhole where the inlet power supply is underground. Such clip-on transformer is mounted at the end of an extension pole to facilitate its use and there are mechanical connection means between the current transformer and the remote end of the pole that facilitates remotely opening and closing the jaws of the current transformer means. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic illustrating an energy diversion measurement device about the power cable and power supply to the consumer which is a line on the same current side. 
     FIG. 2 is a diagramatic view illustrating the box within which the measurement device will be contained, and also the two current transformers. 
     FIG. 3 is a perspective view illustrating a watt-hour meter housing with an adaptor for location in the meter housing. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     An electrical energy diversion measurement device includes a first clip-on current transformer means 10 for operative connection in relationship about an inlet power cable 11 from the electric utility. There is also a second clip-on current transformer means 12 for operative connection in relationship about an inlet power supply to the consumer. The power cable is constituted by the same inlet line power cable 11. The second line of the power supply is not illustrated. 
     The current transformers 10 and 12 are constituted by spring type devices with jaws 13 and 14 which are adapted under the biasing spring action to close together about the cable 11 passing through the encircling jaws 13 and 14. In this fashion, the current transformers 10 and 12 obtain current readings of the cable 11. The current transformers 10 and 12 are connected through a conductor means 15 and 16 respectively to a box containing digital measuring means 17. Each of the conductor means 15 and 16 are constituted by two lines 15A and 15B respectively and 16A and 16B respectively. Lines 15A and 16A lead to terminal 18 of switch means 19, and lines 15B and 16B lead to terminal 20 of the switch means 19. 
     The switch means 19 includes a double ganged switching element 21 which is rotatable for connection respectively with terminals 18 and 20 in a first position, terminals 23 and 24 in a second position, and terminals 25 and 26 in a third position. 
     In the second position indicated by terminals 23 and 24, the current transformer 12 is connected across the digital means through the lines 16A and 16B. This is indicated by letter B which is indicative of the B position of the arm 22 and the B position reflecting the second current transformer 12. Connection with terminals 18 and 20, of lines 15A and 15B connects the first transformer 10 across the digital means 17. This is indicated by numeral A for the current transformer 10 and the numeral A of the switch. 
     In the third position of the switch arm 22, the lines 15B and 16B are connected across the digital measurement means 17 and in this position, the differential between the current sensed by transformer 10 and by transformer 12 is obtained as a response on the digital measurement means 17. 
     The current transformer 12 is mounted at the end of an extension pole 27 whereby a operator can use the pole by gripping the remote handle section 28 and applying the current transformer 12 at a relatively high elevation. Line means 29 is fixed between the end 28 of the pole 27 and a mounting means for the jaw means 13 and 14 of the current transformer 12. This mechanism is attached to jaw member 14 to affect remote opening and closing of the jaw means by the operator. 
     Also included in a kit which is a part of the electricity energy diversion measurement device of the invention is an adaptor 31 arranged for location in the watt-hour meter housing 32. The adaptor includes pins 33 for mounting in the sockets 34 of the housing. The pins 33 permit a continuing connection between appropriate mating sockets 34 so that electricity is supplied continually to the consumer while the diversion measurement device is in operation. Suitable insulation means 35 is located about conductors connected with the pins 33, and the current transformer 10 would be located about the conductor insulation 35 on the same current side as the transformer 12 is connected to the incoming cable to the consumer. This location about the insulated conductor is a connection about the inlet power supply. The insulated conductors constitute effective handles for locating and removing the adaptor 31 in relation to the housing 32. 
     In cases where older style metering is used, the current transformers can be placed directly about the conductors. 
     The diversion measurement device is contained in a box or housing 36 which on the one side mounts the electrical switch 19 and the digital measurement means 17 which is a digital voltmeter, with the display face 37 at the top of the box 36. A compartment 38 is provided on the other side of the box 36 for housing the current transformers 10 and 12 and, if appropriate, the pole 27 which could be of telescopic construction. In this manner, there is provided a convenient diversion testing kit. 
     The two clip on current transformers 10 and 12 are shunted by resistors 39 so that the outputs of lead 15 and 16 are voltages proportional to the primary current. These voltages are measured by the digital voltmeter measurement means 17. The input impedance to the measuring means is relatively high so that measuring means is not affected by any reasonable lead resistance. Accordingly, plug in leads of varying length may be used with no effect upon accuracy. 
     In use, when a utility supplier suspects the diversion of electrical energy, a testman or meter reader would be dispatched to the consumer to measure for this. When the utility requires an instantaneous reading of whether or not there is electricity diversion, the adaptor 31 would be inserted in place of the watt-hour meter and the current transformer 10 would be located around the one carrying line 35 on the adaptor. The second current transformer 12 would be extended to be located in a relationship about the same current line 11 in the zone of the weather guard for line from the distribution pole. This would be the inlet supply lines to the consumer. 
     By turning the switch 19 to position A, the current in current transformer 10 is indicated on the meter, and by turning the switch 19 to position B, the current in current transformer 12 is indicated on the meter. 
     By turning the switch 19 so that the arm 22 is in the position D, namely making contact with terminal 25 and 26 a measurement is obtained of the simultaneous and instantaneous indication of any differential in current the lines surrounded by the transformers 10 and 12. The digital measuring means 37 thereby generates a digital display indicating a representation of the extent of energy diversion if this is existant. In the application of the current transformers 10 and 12 are located in bucking relationship relative to each other such that inaccuracies in the clip-on transformers, which by nature are relatively inaccurate devices, cancel each other. In this fashion, the readings obtained from both transformers are of enhanced accuracy. 
     A further advantage of the invention is that it permits the application of inexpensive clip-on current transformers which, in bucking relationship, overcome inaccuracies of these transformers and thereby facilitate accurate determination of energy diversion. This differential or bucking feature also allows a steady-state reading even with fluctuating currents. Further only a single meter need be read even although there are two currents being measured, since they are bucking and only the differential, which may be zero, is needed to ascertain whether there is energy diversion. 
     A most significant advantage to the invention is that a single person can connect both current transformers and meter measurements at a single location. When the device is used in the differential mode of operation fluctuations in load do not affect the readings since only differential current readings are indicated on the meter. 
     In another embodiment of the invention the current measuring means 17 can be an analog device, and by the indication, for example, of a needle, the indication of energy diversion is obtained. 
     This device and method of this invention can be employed to measure energy division in single and polyphase systems. 
     While preferred embodiments of the invention have been described using specific terms, such description is for illustrative purposes only, and it is to be understood that changes and variations may be made without departing from the intent and scope of the following claims.