The embodiments disclosed herein relate to apparatus for delivering electricity from a high voltage distribution line to a building, and in particular, to apparatus for protecting against theft of electricity from secondary service lines that provide electricity to the buildings.
Electrical utilities throughout the world lose millions of dollars due to non-technical loses. Non-technical loses are often a result of electricity theft, which is a growing problem, especially in developing countries such as Jamaica, Puerto Rico, Dominican Republic, and India, among other countries. In some cases, electricity theft can represent a considerable expense. For example, in 2011, Jamaica estimated that electricity theft amounted to approximately 11.8% of total electricity losses throughout the country.
A common form of electricity theft occurs after power is stepped down from a high voltage distribution line to a lower voltage secondary service line that provides electricity to buildings such as houses and businesses. Specifically, an unauthorized line is connected to an “open secondary”, i.e. a secondary service line that is easily accessible to occupants of the buildings. Common access points for theft include the point at which the secondary service line enters a building, or at the overhead wires near the transformer.
Electricity meters can be installed to measure the amount of power passing through the secondary service line. This enables the power company to track the actual amount of power consumed downstream of the electricity meter, including electricity being stolen from a connection downstream of the electricity meter. However, there are ways to circumvent these electricity meters. For example, it is possible to by-pass the electricity meter by making an unauthorized connection upstream of the electricity meter, in which case, the electricity theft cannot be detected because it is stolen prior to being measured by the electricity meter.
In order to counteract this type of theft, some meters are installed on utility poles near the overhead high voltage distribution lines. Mounting the meters higher up can make it more difficult to bypass the meter. However, even with the electricity meters placed high up in the air, theft is still possible because there remains an open secondary between the transformer and the meter.
According to some embodiments, there is an apparatus for protecting against theft of electricity from a distribution transformer that transforms electricity from a higher distribution voltage to a lower secondary voltage. The distribution transformer is housed in a transformer housing having secondary terminals extending therefrom. The apparatus includes a protective enclosure rigidly attachable to an outer portion of the transformer housing adjacent the secondary terminals. The protective enclosure is configured to enclose the secondary terminals and to house a plurality of electricity meters for measuring electricity usage. The protective enclosure also has a plurality of service line apertures sized and shaped to receive a plurality of secondary service lines therethrough. Each secondary service line is electrically connectable to one of the electricity meters. The apparatus also includes at least one secondary bus line located within the protective enclosure for electrically connecting the secondary terminals to the plurality of electricity meters.
The protective enclosure may also include a meter housing having an interior meter chamber configured for housing the electricity meters. The meter housing also has opening in a back side thereof. The protective enclosure also includes a throat extending outwardly from the back side of the meter housing around the opening to the outer portion of the transformer housing. The throat may be configured to provide an enclosed passageway between the secondary terminals and the meter chamber for receiving the secondary bus line therethrough.
The protective enclosure may also include a mounting structure for mounting the plurality of electricity meters within the meter housing.
The throat may space apart the transformer housing from the meter housing, and the protective enclosure may include a support bracket offset from the throat for securing the transformer housing to the meter housing.
The throat may have a first end mounted to the transformer housing, and a second end with a flange mounted to the meter housing. The first end may be welded to the transformer housing. The flange may be secured to the meter housing using fasteners. The apparatus may also include a gasket between the second flange and the meter housing.
The protective enclosure may include an access door for providing access to the electricity meters, and an anti-tampering device for restricting unauthorized opening of the access door. The anti-tampering device may include a lock for closing the access door. The anti-tampering device may include a sensor for detecting unauthorized opening of the access door.
The apparatus may include a disconnect switch operatively connected to the anti-tampering device. The disconnect switch may be configured to disconnect power to a downstream location when the anti-tampering device detects unauthorized opening of the access door.
According to some embodiments, there is an apparatus for delivering electricity from a high voltage distribution line to a plurality of buildings. The apparatus includes a distribution transformer for transforming electricity from a higher distribution voltage to a lower secondary voltage. The distribution transformer is housed in a transformer housing having secondary terminals extending therefrom. The apparatus also includes a protective enclosure rigidly attachable to an outer portion of the transformer housing adjacent the secondary terminals. The protective enclosure is configured to enclose the secondary terminals and to house a plurality of electricity meters for measuring electricity usage. The protective enclosure has a plurality of service line apertures sized and shaped to receive a plurality of secondary service lines therethrough. Each secondary service line is electrically connectable to one of the electricity meters. The apparatus also includes at least one secondary bus line located within the protective enclosure for electrically connecting the secondary terminals to the plurality of electricity meters.
According to some embodiments, there is a method of refurbishing a pre-existing transformer housing to deter theft of electricity. The pre-existing transformer housing has a distribution transformer therein for transforming electricity from a higher distribution voltage to a lower secondary voltage and a plurality of secondary terminals extending from the pre-existing transformer housing. The method includes dismounting the pre-existing transformer housing from a utility pole, disassembling the pre-existing transformer housing and removing the distribution transformer therefrom, and rigidly attaching a protective enclosure to an outer portion of the transformer housing adjacent the secondary terminals. The protective enclosure is configured to enclose the secondary terminals and to house a plurality of electricity meters for measuring electricity usage. The protective enclosure has a plurality of service line apertures sized and shaped to receive a plurality of secondary service lines therethrough. Each secondary service line is electrically connectable to one of the electricity meters. The method also includes installing at least one secondary bus line within the protective enclosure for electrically connecting the secondary terminals to the plurality of electricity meters.
The step of rigidly attaching the protective enclosure to the outer portion of the transformer housing may include providing a meter housing having an interior meter chamber configured for housing the electricity meters, and rigidly attaching a throat to the pre-existing transformer housing and to the meter housing. The meter housing has an opening in a back side thereof, and the throat extends outwardly from the back side of the meter housing around the opening to the outer portion of the transformer housing. The throat is configured to provide an enclosed passageway between the secondary terminals and the interior meter chamber for receiving the secondary bus line therethrough.
The method may also include installing the electricity meters within the protective enclosure and electrically connecting the secondary terminals to the electricity meters using the secondary bus line.
Other aspects and features will become apparent, to those ordinarily skilled in the art, upon review of the following description of some exemplary embodiments.
The drawings included herewith are for illustrating various examples of the present specification:
Referring to
With reference to
The enclosure 20 is generally made from rigid, high-strength materials that are resistant to being cut, bent, punctured or otherwise deformed. For example, the enclosure 20 may be made from steel such as high-gauge plate steel.
Referring still to
As shown in
The electricity meters 24 within the protective enclosure 20 measure electricity usage. In this case, the electricity meters 24 are configured to measure electrical power passing through the secondary service lines 16. As shown in
The input of each meter 24 is connected to the distribution transformer 22 via the secondary bus line 26. The output of each meter 24 is connected to a respective dedicated secondary service line 16 and exits the enclosure 20 through one or more outlet ports or service line apertures 39. As shown in
Referring still to
As shown, the interior chambers 40, 42 are created by separate housings. The transformer housing 50 defines the interior transformer chamber 40, and the protective enclosure 20 includes a meter housing 52 defining the interior meter chamber 42. The enclosure 20 also includes a throat 54 rigidly attached to the transformer housing 50 and the meter housing 52. The throat 42 defines the enclosed passageway 44 connecting the interior transformer chamber 42 to the interior meter chamber 42. Using separate housings can provide a number of benefits. For example, the separate housings may help to isolate components of the distribution transformer 22 from the electricity meter 24. This can be particularly helpful when the distribution transformer 22 is immersed within the coolant 30. The separate housings can also allow refurbishing of a pre-existing transformer housing to include the separate meter housing and electricity meters therein.
As shown in the illustrated embodiment, the transformer housing 50 may have a generally cylindrical shape, and the meter housing 52 may have a generally box-like or cuboid shape. Furthermore, the throat 54 may extend from a circumferential outer portion of the transformer housing 50 to a flat outer portion of the meter housing 52. In other examples, the transformer housing 50, meter housing 52, and throat 54 may have other shapes and sizes. For example, the transformer housing 50 may have a rectangular or cuboid shape (e.g., as shown in
In some examples, the transformer housing 50 may be included as part of the protective enclosure 20. Furthermore, while the illustrated embodiment includes a separate transformer housing 50 and meter housing 52, in other examples, the enclosure 20 may be manufactured as a single housing having the interior transformer chamber 40, the interior meter chamber 42, and the enclosed passageway 44 in a singular unit.
As described above, the secondary bus line 26 is located within the protective enclosure 20 to inhibit or deter electricity theft by avoiding an “open secondary”. For example, with reference to
After the low voltage terminals 56, the secondary bus line 26 includes cables or wires 57 that extend through the throat 54 and into the meter housing 52. Specifically, as shown in
Referring still to
As shown in the illustrated embodiment, the throat 54 spaces apart the transformer housing 50 from the meter housing 52. In such cases, the protective enclosure 20 may include one or more support brackets 70 for helping to secure the transformer housing 50 to the meter housing 52. As shown, the support brackets 70 may have a similar length as the throat 54 and are spaced apart from the throat 54. Specifically, there may be two support brackets 70 located below the throat 54. In other examples, the throat 54 itself may be sized and shaped to provide sufficient strength to support the meter housing 52 from the transformer housing 50 without the use of the support brackets 70.
The meter housing 52 also includes a mounting structure for mounting the electricity meters 24 within the interior meter chamber 42. For example, the mounting structure may include a DIN rail 38 supported on a mechanical panel 72 within the meter housing 52. In other examples, there may be another type of mounting structure such as a receptacle for receiving socket-meters.
Referring again to
The apparatus 10 may also include an anti-tampering device for restricting unauthorized access through the access door 80. For example, the anti-tampering device may include a lock 82 for closing the access door 80. Additionally or alternatively, the anti-tampering device may include a sensor 84 for detecting unauthorized opening of the access door 80. The sensor 84 may be a proximity sensor such as an optical sensor or a magnetic sensor that detects when the access door 80 is opened. In the event of unauthorized access, the sensor 84 may be configured to trigger an alarm, or shut-off power downstream of the apparatus 10.
Referring now to
Still referring to
An anti-tampering device 102 (such as the lock 82 or the sensor 84 described above) may be operatively connected to the disconnect switch 100 (e.g. via the processor 96). Accordingly, when the anti-tampering device 102 detects unauthorized opening of the access door 80, the processor 96 may operate the disconnect switch 100 to shut off electrical power downstream of the apparatus 10.
In some examples, the disconnect switch 100 may be separate from the electricity meter 24. For example, the disconnect switch 100 may be included as part of the anti-tampering device 102. Alternatively, the disconnect switch 100 may be an individual component on its own, and in some cases, may be configured to disconnect the high voltage distribution line 14 from the distribution transformer 22.
Referring now to
As shown, the transformer housing 150 has a cuboid shape, and the meter housing 152 also has a cuboid shape. Furthermore, the throat 154 extends from a flat outer portion of the meter housing 152 to a flat outer portion of the transformer housing 150. Alternatively, the meter housing 152 may be mounted directly to the transformer housing 150 without use of the throat 154.
With reference to
Referring now to
Step 210 includes dismounting the pre-existing transformer housing from a utility pole. The pre-existing transformer housing generally has an interior transformer chamber with a distribution transformer therein, which may be similar to the distribution transformers 22, 122. The pre-existing transformer housing may have a generally cylindrical shape similar to the transformer housing 50, or a cuboid shape similar to the transformer housing 150. The pre-existing transformer could also have other shapes.
The pre-existing transformer housing also has a plurality of secondary terminals extending from the pre-existing transformer housing, such as the bushings or terminals 56 shown in
Step 220 includes dissembling and removing the distribution transformer from the pre-existing transformer housing. For example, step 220 may include opening the pre-existing transformer housing and removing the transformer coil assembly from the pre-existing transformer housing along with any coolant or oil therein. Paint and other surface coatings may also be removed, for example, by sandblasting the pre-existing transformer housing.
Step 230 includes rigidly attaching a protective enclosure to an outer portion of the transformer housing adjacent the secondary terminals. The protective enclosure is configured to enclose the secondary terminals and to house a plurality of electricity meters for measuring electricity usage. The protective enclosure also has a plurality of service line apertures sized and shaped to receive a plurality of secondary service lines therethrough such as the apertures 39 within the protective enclosure 20 described above.
In some examples, the protective enclosure may include a meter housing such as the meter housings 52 and 152 described above. The meter housing is generally separate from the pre-existing transformer housing. The meter housing may have an interior meter chamber configured to receive one or more of the electricity meters. Furthermore, the meter housing may include a mounting structure for mounting the electricity meters within the interior meter chamber. For example, the mounting structure may include a DIN-rail for receiving DIN-style electricity meters, or one or more receptacles for receiving socket meters.
When the protective enclosure includes a meter housing, step 230 may also include rigidly attaching a throat to the pre-existing transformer housing and to the meter housing. The throat may be similar to one of the throats 54 and 154 described above.
The throat generally defines an enclosed passageway between the secondary terminals and the interior meter chamber for receiving a secondary bus line therethrough. More specifically, the throat may extend outwardly from a back side of the meter housing around an opening therein (such as the opening 58 in the meter housing 50) to the outer portion of the transformer housing adjacent the secondary terminals.
In some examples, the throat may be welded to the pre-existing transformer housing and may be bolted to the meter housing. In other examples, the throat may be attached using other fastening techniques.
When attaching the throat to the pre-existing transformer housing, the throat is generally positioned to overlie the secondary terminals extending from the pre-existing transformer housing. Alternatively, one or more openings may be formed in the pre-existing transformer housing at a location corresponding to the position of the throat, and terminals or bushings may be installed therein. In such cases, the openings may be formed by drilling or cutting away material from the pre-existing transformer housing.
Step 240 includes installing a secondary bus line within the protective enclosure for electrically connecting the secondary terminals to the electricity meters. For example, the secondary bus line may include wires, cables, busbars, and other electrical conductors such as with the secondary bus line 26 described above. Step 240 may also include reassembling the pre-existing transformer housing and reinstalling the distribution transformer therein.
The method 200 may also include step 250 of installing the electricity meters within the protective enclosure and electrically connecting the secondary terminals to the electricity meters using the secondary bus line (e.g. so as to electrically connect the distribution transformer to the electricity meters). The electricity meters may be pre-installed within the meter housing, or may be installed in the field.
One or more of the apparatus and methods described herein can be used to help prevent electricity theft. Specifically, the apparatus and methods can help overcome the problem of theft at “open secondary” lines. One reason for this is that the secondary bus line is enclosed within a protective enclosure. This protective enclosure avoids the existence of open secondary service lines, and thus removes an opportunity for making unauthorized connection to the power distribution network. In addition, the electricity meters can now be located within the enclosure as opposed to being located at the residential or commercial property. This can avoid possible tampering or bypassing of the electricity meters. The enclosure can also include anti-tampering devices for restricting unauthorized access to the enclosure, which can further deter or help prevent tampering of the electricity meters.
While the above description provides examples of one or more apparatus, methods, or systems, it will be appreciated that other apparatus, methods, or systems may be within the scope of the present description as interpreted by one of skill in the art.