Electricity meter with thermal protection

Abstract

The power meter is connected to a utility power line and a load via a meter mounting device and determines power consumption between the utility power line and the load. The power meter includes a base plate having at least one blade (114a-d) configured to couple to a corresponding jaw of the meter mounting device to electrically connect the power meter to the utility power line and the load, and a service switch operable to enable or disable the electrical connection between the utility power line and the power meter. The base plate further includes a thermal device disposed adjacent to the at least one blade, the thermal device configured to control the service switch to disable the electrical connection between the utility power line and the power meter when a temperature of the thermal device exceeds a temperature threshold.

Description

[Technical Field]

[0001] Related Applications This application claims priority from UK Patent Application No. 2218912.0, filed December 15, 2022, which is incorporated herein by reference in its entirety.

[0002] Technical Field The present invention relates to an electric power meter for connection to a utility power line and a load via a meter mounting device. [Background technology]

[0003] An electric power meter or metering device measures electrical energy or power consumption between a utility line and a load to determine the amount of electrical energy or power consumed by a home, business, or powered device.

[0004] In a typical residential installation, an electric power meter is attached to a utility line and a load via a meter mounting device (or meter socket). The electric power meter includes a base plate with one or more electrical contacts, specifically blades. The blades connect to corresponding utility power line and load jaws on the meter mounting device, thereby connecting the electric power meter to the power line and load, respectively, and enabling measurement of load current and load voltage. When the electric power meter is connected to the meter mounting device, a significant amount of electric current flows across the blades on the base plate. Summary of the Invention [Problem to be solved by the invention]

[0005] Typically, in residential installations, the meter mounting device and the connected electric meter are grounded outdoors, and thus the jaws of the meter mounting device and the blades of the electric meter may be exposed to outdoor conditions (such as extreme temperatures, moisture, etc.). Over the life of the meter mounting device, it is not uncommon for the jaws of the meter mounting device to deteriorate. In some instances, the jaws may deteriorate sufficiently to introduce non-trivial resistance into the connection between the jaws of the meter mounting device and one or more blades of the electric meter's base plate. This, in turn, may cause the electric meter, particularly the one or more blades and the base plate, to overheat and heat up. Depending on the severity of the deterioration, the temperature increase may compromise the mechanical integrity of the base plate, which is typically made of plastic (this may occur at approximately 200 degrees Celsius). For example, the base plate may begin to melt, deform, or otherwise suffer structural damage.

[0006] In known configurations, a temperature monitoring or detection device is incorporated into the power meter electronics to monitor the power meter for overheating. However, the power meter electronics is typically isolated from the contact points between the jaws of the meter mounting device and the blades of the power meter by multiple thermal barriers and shrouds, such as by a base plate body and a base plate shroud. As such, known configurations are generally not very effective at providing early detection of overheating and are primarily used to manage the operating temperature of one or more of the power meter electronics.

[0007] Further known configurations may incorporate an RF arc detector to detect overheating of the power meter. While a promising solution, the use of RF arc detection methods requires a separate electronic circuit assembly, which can be expensive to implement.

[0008] A need exists to provide an improved electricity meter that allows for early detection of deleterious thermal events at the connection between the blades of the base plate and the jaws of the meter mounting device. [Means for solving the problem]

[0009] According to the present invention in a first aspect, there is provided an electricity meter for connection to a utility power line and a load via a meter mounting device and for determining electricity consumption between the utility power line and the load, The electricity meter is a base plate having at least one blade configured to couple to a corresponding jaw of the meter mounting device to electrically connect the electricity meter to the utility power line and the load; a service switch operable to enable or disable an electrical connection between the utility power line and the power meter; The base plate further includes a thermal device disposed adjacent to the at least one blade, the thermal device configured to control a service switch to disable an electrical connection between the utility power line and the power meter when a temperature of the thermal device exceeds a temperature threshold.

[0010] Optionally, a thermal device is attached to the base plate.

[0011] Optionally, the power meter further comprises a base plate shroud connected to the base plate, the thermal device being disposed in an interior chamber formed between the base plate and the base plate shroud.

[0012] Optionally, a service switch is provided in the internal chamber.

[0013] Optionally, the power meter further comprises a conductive body, the at least one blade extending from the conductive body, and the thermal device disposed adjacent to the conductive body. Optionally, the thermal device contacts the conductive body.

[0014] Optionally, the conductive body is disposed within the internal chamber and the at least one blade is disposed external to the internal chamber.

[0015] Optionally, the thermal device forms part of the circuit, the thermal device being configured to shut off the circuit if the temperature of the thermal device exceeds a temperature threshold.

[0016] Optionally, the service switch is controlled to enable an electrical connection between the utility power line and the power meter when the circuit is closed, and to disable the electrical connection between the utility power line and the power meter when the circuit is interrupted.

[0017] Optionally, the power meter further comprises power meter electronics comprising a microprocessor, the thermal device forming a circuit with the microprocessor.

[0018] Optionally, when the circuit between the microprocessor and the thermal device is interrupted, the microprocessor is configured to control a service switch to disable the electrical connection between the utility power line and the power meter.

[0019] Optionally, the power meter electronics are isolated from the thermal device by a baseplate shroud.

[0020] Optionally, the thermal device forms a circuit with a service switch, the service switch being configured to disable the electrical connection between the utility power line and the power meter when the circuit is interrupted.

[0021] Optionally, the base plate comprises first and second blades, a first thermal device disposed adjacent to the first blade, and a second thermal device disposed adjacent to the second blade.

[0022] Optionally, the first and second thermal devices are mounted to a base plate.

[0023] Optionally, the thermal device comprises a thermal cut-off fuse or a thermal switch.

[0024] According to the present invention in a further aspect there is provided a base plate for an electricity meter, comprising: an electric power meter connected to the utility power line and the load via a meter mounting device and determining an electric power consumption between the utility power line and the load; The base plate is at least one blade configured to couple to a corresponding jaw of the meter mounting device to electrically connect the electricity meter to the utility power line and the load; and a thermal device disposed adjacent to at least one blade, the thermal device configured to control a service switch to disable an electrical connection between the utility power line and the power meter when a temperature of the thermal device exceeds a temperature threshold.

[0025] Optionally, the base plate further comprises a service switch. [Brief explanation of the drawings]

[0026] [Figure 1] 1 illustrates an exploded view of an exemplary electricity meter. [Figure 2] 1 illustrates an exploded view of an exemplary base plate and base plate shroud. [Figure 3] 1 illustrates a front view of an exemplary base plate. [Figure 4] FIG. 1 is a schematic block diagram of an exemplary electricity meter. DETAILED DESCRIPTION OF THE INVENTION

[0027] Generally, disclosed herein is an electric power meter for connecting to a utility power line and a load via a meter mounting device. The electric power meter includes a base plate with at least one blade configured to connect to a utility power line jaw (connected to the utility power line) or a load jaw (connected to the load) of the meter mounting device to electrically connect the electric power meter to the utility power line or the load. The electric power meter further includes a service switch that can be closed and opened to enable or disable the electrical connection between the utility power line and the electric power meter. An exemplary base plate of the present invention further includes a thermal device disposed adjacent and / or proximate to the at least one blade. The thermal device is configured to control the service switch to open the service switch and thereby disable the electrical connection between the utility power line and the electric power meter when a temperature of the thermal device exceeds a temperature threshold.

[0028] The thermal device of the exemplary electricity meter disclosed herein forms part of the base plate configuration and, in certain embodiments, is attached to a base plate body of the base plate. The base plate body can be connected to a base plate shroud that forms an internal chamber therebetween, with the thermal device disposed within the internal chamber. As such, the thermal device of the present invention is not thermally isolated from the contact point between the at least one blade and the jaw by multiple internal barriers and shrouds, as is typical in known configurations. In particular, the thermal device is not separated from the contact point between the at least one blade and the jaw by the base plate shroud.

[0029] By providing the thermal device on the base plate and in proximity to the at least one blade, the thermal device experiences temperatures similar to those experienced by the at least one blade and / or the base plate body, and thus temperature increases in the blade and / or base plate body can be detected more quickly, allowing corrective action (such as disabling power supply from the utility power lines to the power meter) to be taken before catastrophic damage to the base plate and / or other components of the power meter occurs due to overheating.

[0030] 1 illustrates an exploded view of an exemplary power meter 100. The exemplary power meter 100 is configured to connect to a utility power line and a load via a meter mounting device (not shown). The meter 100 includes a base plate 102. The exemplary power meter 100 further includes a base plate shroud 104, power meter electronics 106, an electronics housing 108, and a power meter housing 110.

[0031] 2 shows an exploded view of the base plate 102 and the base plate shroud 104. The base plate 102 includes a base plate body 112, which may be formed completely or at least partially from plastic. The base plate 102 and the base plate shroud 104 are connectable to form an interior chamber between the base plate body 112 and the base plate shroud 104.

[0032] The base plate 102 includes blades 114a-d. The base plate 102 may further include a current coil arrangement including conductive bodies 116a-d. The conductive bodies 116a-d are configured to transmit current between the blades. In the exemplary arrangement shown in Figure 2, each blade 114a-d is integrally formed with a respective conductive body 116a-d.

[0033] 2, conductive body 116a is electrically coupled to conductive body 116c (e.g., via intermediate component 117), and thus current can flow between blades 114a and 114c. Similarly, conductive body 116b is electrically coupled to conductive body 116d (e.g., via intermediate component 117), and thus current can flow between blades 114b and 114d. Those skilled in the art will recognize that in alternative configurations, each blade 114a, 114c may be integrally formed with conductive bodies 116a, 116c (i.e., provided as a single component), and blades 114b, 114d may be integrally formed with conductive bodies 116b, 116d (i.e., provided as a single component).

[0034] The blades 114a-d may extend through respective openings 120a-d formed in the base plate body 112 such that the blades 114a-d are disposed outside of an internal chamber formed between the base plate body 112 and the base plate shroud 104. The current transfer portions 116a-d may be housed within the internal chamber.

[0035] The blades 114a-d are configured to connect to a meter mounting device. In use, when the electricity meter 100 is connected to the meter mounting device, the blades 114a-d are received by the utility power line jaws of the meter mounting device (connected to the utility power line) and the load jaws of the meter mounting device (connected to the load). In the exemplary configuration shown in FIG. 2, the base plate 102 includes four blades. Two blades 114a and 114b connect to corresponding utility power line jaws of the meter mounting device, and two blades 114c and 114d connect to corresponding load jaws of the meter mounting device.

[0036] The connections between blades 114a-d and the utility power line and load jaws facilitate power flow from the utility power line to the load via the utility power line jaws, the blades received by the utility power line jaws, the conductive bodies, the blades received by the load jaws, and the load jaws. For example, blade 114a may be received by the utility power line jaw of the meter mounting device, and blade 114c may be received by the load jaw of the meter mounting device. In this embodiment, power flows from the utility power line to the load via the utility power line jaws, blade 114a, conductive bodies 116a and 116c, blade 114c, and the load jaws. Similarly, blade 114b may be received by the utility power line jaw of the meter mounting device, and blade 114d may be received by the load jaw of the meter mounting device, such that power flows from the utility power line to the load via the utility power line jaws, blade 114b, conductive bodies 116b and 116d, blade 114d, and the load jaws.

[0037] The exemplary electricity meter 100 shown in Figures 1 and 2 is connected to a typical ANSI 2S meter mounting device. Those skilled in the art will recognize that alternative electricity meters may be connected to different meter mounting devices and may, for example, have different numbers and / or arrangements of blades.

[0038] FIG. 3 illustrates a plan view of an exemplary base plate 102. As can be seen in FIG. 3, the base plate 102 includes thermal devices 126a and 126b. The thermal devices 126a and 126b are attached to the base plate 102. In the particular embodiment illustrated in FIG. 3, the thermal devices 126a and 126b are attached to the base plate body 112. The thermal devices 126a and 126b may be attached, for example, to corresponding cavities formed in the base plate body 112, although one skilled in the art will recognize that there are alternative ways in which the thermal devices 126a and 126b may be attached to the base plate 102. The thermal devices 126a and 126b are electrically isolated from utility services. For example, the thermal devices 126a and 126b may be attached to corresponding non-conductive cavities. One skilled in the art will be familiar with alternative methods of electrically isolating components.

[0039] The thermal devices 126a, 126b may be attached to the base plate 102 such that the thermal devices 126a, 126b are located within an internal chamber formed between the base plate body 112 and the base plate shroud 104 when the base plate 102 and the base plate shroud 104 are connected.

[0040] Thermal devices 126a, 126b are mounted adjacent to each blade 114a, 114b. In the exemplary configuration shown in FIG. 3, thermal device 126a is mounted adjacent to blade 114a, and thermal device 126b is mounted adjacent to blade 114b. Those skilled in the art will recognize that alternative configurations may include a different number of thermal devices, for example, an alternative configuration may include a single thermal device or more than two thermal devices. Additionally, one or more thermal devices may be mounted adjacent to alternative blades to those shown in FIG. 3.

[0041] As previously mentioned, at least a portion of the blades 114a, 114b (and in the exemplary configuration, substantially all of the blades 114a, 114b) extend through respective openings 120a, 120b in the base plate body 112 such that the blades 114a, 114b are disposed outside the internal chamber. Additionally, the blades 114a, 114b extend from conductive bodies 116a, 116b disposed inside the internal chamber. In the exemplary configuration of FIG. 3, the thermal devices 126a, 126b may be disposed adjacent to the conductive bodies 116a, 116b disposed inside the internal chamber and from which the respective blades 114a, 114b extend. In an exemplary configuration, there may be no components between the conductive bodies 116a, 116b and the thermal devices 126a, 126b, and in a further exemplary configuration, the thermal devices 126a, 126b may contact at least a portion of the conductive bodies 116a, 116b from which each blade 114a, 114b extends. Because the blades 114a, 114b and the conductive bodies 116a, 116b are good thermal conductors, the temperature of the conductive bodies 116a, 116b will be substantially the same as the temperature of the blades 114a, 114b (which contact the jaws of the meter mounting device).

[0042] In this manner, the thermal devices 126a, 126b are not isolated from the blades 114a, 114b or the base plate body 112 by the base plate shroud 104, thus reducing the overall thermal impedance between the jaw / blade connection and the thermal devices 126a, 126b. Thus, the thermal devices 126a, 126b experience temperatures similar to those experienced by the base plate 102 and blades 114a, 114b.

[0043] 3, thermal devices 126a, 126b include thermal cut-out fuses that form a circuit with other components of power meter 100 and are configured to interrupt (or open) the circuit when the temperature of one or both of the thermal cut-out fuses exceeds a temperature threshold. Exemplary thermal cut-out fuses may be those provided by Cantherm.

[0044] Each of the thermal interrupt fuses includes a body 134a, 134b having a thermal element disposed therein. In an exemplary configuration, the bodies 134a, 134b of the thermal interrupt fuses are attached adjacent to the respective blades 114a, 114b. In the particular embodiment shown in FIG. 3, the bodies 134a, 134b are attached adjacent to the conductive bodies 116a, 116b from which the respective blades 114a, 114b extend. The thermal element is configured to melt when it reaches a temperature threshold, thereby interrupting the circuit. The thermal interrupt fuses may be disposable. Those skilled in the art will be familiar with the operation of thermal interrupt fuses. Further details are not provided herein.

[0045] Those skilled in the art will recognize that, in alternative configurations, alternative thermal devices may be attached to the base plate 102 such that they are disposed within an internal chamber formed between the base plate body 112 and the base plate shroud 104. For example, in an alternative configuration, the thermal devices 126a, 126b may comprise thermal cutoff switches configured to interrupt (or open) a circuit when a threshold temperature is exceeded and reclose the circuit when the temperature drops below the threshold temperature. In a further alternative configuration, the thermal devices may comprise temperature sensors configured to collect data indicative of the temperature of the blades and transmit the data to the power meter electronics 106 for processing and determining whether a temperature threshold has been exceeded. Those skilled in the art will be able to envision other configurations.

[0046] The power meter 100 further includes a service switch 140 or a service disconnect driver / relay, as shown in FIG. 4 . FIG. 4 is a schematic block diagram of the electrical components of the power meter 100. The service switch 140 may be attached to the base plate 102 and may itself be received within an interior chamber formed between the base plate body 112 and the base plate shroud 104. When the power meter 100 is connected to a meter-mounting device, the service switch 140 is configured to enable an electrical connection between the utility power line and the power meter 100 when closed and to disable an electrical connection between the utility power line and the power meter 100 when open. The service switch 140 may be controllable by the thermal devices 126 a, 126 b via the power meter electronics 106, specifically via a microprocessor 142 of the power meter electronics 106.

[0047] The power meter electronics 106 may be configured to determine power consumption between the utility power line and a load. In addition to the microprocessor 142, the power meter electronics 106 may further include one or more of a measurement circuitry / signal conditioning module 144, an AMR interface 146, an LCD or other display 148, and, optionally, an RF interference detector 150. As previously mentioned, the power meter electronics 106 may be mounted inside the electronics housing 108, in contrast to the thermal devices 126a, 126b, which are mounted in an interior chamber formed between the base plate 102 and the base plate shroud 104. In this manner, the power meter electronics 106 may be isolated from the base plate 102 by the base plate shroud 104.

[0048] 4, the thermal devices 126a, 126b are electrically connected to the power meter electronics 106, and specifically to the microprocessor 142. In the exemplary configuration shown in FIGS. 1-4, the thermal devices 126a, 126b form a circuit with the microprocessor 142 of the power meter electronics 106.

[0049] As shown in FIG. 3, thermal devices 126a, 126b, which in this particular embodiment comprise thermal cutoff fuses, are electrically connected in series via leads / wires 160a-c. In the exemplary configuration of FIG. 3, leads 160a, 160b terminate at connector 162 configured for electrical connection to power meter electronics 106, specifically to microprocessor 142. Thermal devices 126a, 126b may be connected to microprocessor 142 via pull-up resistors connected to V3P3 (a 3.3 VDC DC power source). Those skilled in the art will recognize that such connections are exemplary only and can envision other ways in which thermal devices 126a, 126b may be connected to microprocessor 142. Microprocessor 142 is electrically connected to and in communication with service switch 140.

[0050] In an alternative configuration, the thermal devices 126a, 126b may be directly connected to the service switch 140. That is, the thermal devices 126a, 126b may form a circuit with the service switch 140 rather than the microprocessor 142, as shown by the dashed lines between the thermal devices 126a, 126b and the service switch 140 in FIG.

[0051] The use of the power meter 100 for early detection of harmful thermal events in the baseplate 102 is described below with reference to FIGS.

[0052] In use, the power meter 100 is connected to a utility power line and a load in a home / building via a meter mounting device. The power meter 100 is attached to the meter mounting device by engaging the blades 114a-d of the base plate 102 with corresponding jaws of the meter mounting device. As previously described, due to the connection between the blades 114a-d of the base plate 102 and the jaws of the meter mounting device, power from the utility power line flows through the power meter 100 to the load.

[0053] In one exemplary configuration, thermal devices 126a, 126b include thermal cut-out fuses, which form a circuit with microprocessor 142. During operation of power meter 100, when the circuit formed between the thermal cut-out fuses and microprocessor 142 is closed, microprocessor 142 is configured to control service switch 140 to operate in a closed position such that an electrical connection between the utility power line and power meter 100 is enabled. When service switch 140 is in the closed position, power flows from the utility power line to a load through the power meter.

[0054] If the temperature of the thermal fuse, and more particularly the temperature of the thermal element within the thermal fuse, does not exceed the temperature threshold, the circuit formed by the thermal fuse with the microprocessor 142 remains closed.

[0055] Those skilled in the art will recognize that the temperature of the thermal interrupt fuse indicates the temperature of the base plate 102 and / or the blades 114a, 114b. As such, the temperature threshold of the thermal devices 126a, 126b (which are thermal interrupt fuses in this example) may be selected to be below a temperature at which irreversible damage to the base plate 102 or other components of the power meter 100 may occur. For example, the base plate body 112 is typically formed from a plastic material, which in one particular example may be a polycarbonate resin such as LEXAN® 500R, which may have a melting point of approximately 150°C. In this particular example, the temperature threshold may be one or more of substantially 110°C, substantially 120°C, substantially 130°C, and substantially 140°C. Those skilled in the art will recognize that the base plate may be formed from alternative materials with alternative melting points, and the temperature threshold may be selected accordingly. As long as the temperature of the thermal devices 126a, 126b remains below the temperature threshold, the circuit formed between the microprocessor 142 and the thermal cut-off fuse remains closed and the service switch 140 remains in the closed position.

[0056] Over the life of the electricity meter 100 and meter mounting device, the jaws of the meter mounting device and / or the blades 114a-d of the electricity meter 100 may deteriorate, for example, due to experienced inclement weather or from repeated connection and disconnection of the blades 114a-d of the electricity meter 100 to the jaws of the meter mounting device. This deterioration may cause resistance in the connection between the blades 114a-d and the jaws, and temperatures at the connection may begin to rise.

[0057] As the temperature of the connection between the blades 114a-d and the jaws increases, so does the temperature of the thermal interrupt fuse. Due to the proximity of the thermal interrupt fuse to the blades 114a, 114b, the temperature increase experienced by the blades 114a, 114b transitions with minimal delay to a temperature increase in the thermal interrupt fuse due to the thermal interrupt fuse being attached to the base plate 102 and adjacent to the blades 114a, 114b. Because the thermal interrupt fuse is not physically isolated from the connection between the blades 114a-d and the jaws by multiple shrouds, including the base plate shroud 104, the temperature increase in the thermal interrupt fuse occurs with minimal delay.

[0058] If the temperature rise at the blade / jaw connection causes the temperature of one or both of the thermal fuses to exceed a threshold temperature, the circuit formed between the thermal fuses and the microprocessor 142 is interrupted.

[0059] Microprocessor 142 is configured to control service switch 140 to disable the electrical connection between the utility power line and power meter 100 when the circuit formed between the thermal interrupt fuse and microprocessor 142 is interrupted. In this manner, all of the service load from the utility power line is removed from power meter 100 and the meter mounting device.

[0060] As described above, the temperature thresholds of the thermal devices 126a, 126b are set to be below temperatures at which irreversible damage to the base plate 102 or other components of the power meter 100 may occur, so that the thermal interrupt fuses may interrupt the circuit and the service load may be removed from the utility power line before such irreversible structural damage occurs. Thus, in the event of a detrimental temperature event, the only components of the power meter 100 requiring replacement are the thermal interrupt fuse(s), rather than the entire base plate.

[0061] The microprocessor 142 may further be configured to control the transmitter of the power meter 100 to send an alarm signal if the circuit formed by the thermal interrupt fuse is interrupted. The alarm signal may be sent to a utility control center, for example, to indicate that a harmful temperature event has occurred and that a service visit to the power meter 100 and the meter-mounted device location is necessary.

[0062] The above operation is described with reference to the electric power meter 100 including thermal devices 126a, 126b that include thermal cutoff fuses. Those skilled in the art will recognize that, in an alternative configuration, the thermal devices 126a, 126b may include thermal cutoff switches. The thermal cutoff switches operate similarly to the thermal cutoff fuses described above, but are configured to reclose the circuit once the temperature of the thermal element drops below a threshold temperature. In a further alternative configuration, the thermal devices 126a, 126b may include temperature sensors mounted adjacent the blades and configured to transmit temperature data to the microprocessor 142. The microprocessor 142 may be configured to disable the electrical connection between the utility power line and the electric power meter 100 if the received temperature data indicates that the temperature at the temperature sensor exceeds a threshold temperature. Those skilled in the art will recognize that alternative temperature or thermal devices may be used.

[0063] It will be appreciated by those skilled in the art that various modifications may be made to the above-described embodiments without departing from the scope of the present invention.

Claims

1. 1. An electric power meter for connecting to a utility power line and a load via a meter mounting device and for determining electric power consumption between said utility power line and said load, said electric power meter comprising: The electricity meter is a base plate including at least one blade configured to couple to a corresponding jaw of the meter mounting device to electrically connect the electricity meter to the utility power line and the load; a service switch operable to enable or disable an electrical connection between the utility power line and the power meter; the base plate further comprises a thermal device disposed adjacent to the at least one blade, the thermal device configured to control the service switch to disable an electrical connection between the utility power line and the power meter when a temperature of the thermal device exceeds a temperature threshold. Electricity meter.

2. the thermal device is attached to the base plate; The electricity meter of claim 1.

3. the electricity meter further comprises a base plate shroud connected to the base plate; the thermal device is disposed in an internal chamber formed between the base plate and the base plate shroud; 3. The electricity meter according to claim 1 or 2.

4. The service switch is provided in the internal chamber.

4. The electricity meter of claim 3.

5. The electricity meter further comprises a conductive body; the at least one blade extending from the conductive body; the thermal device is disposed adjacent to the conductive body; An electricity meter according to any one of claims 1 to 4.

6. the conductive body is disposed in the internal chamber; the at least one blade is disposed outside the internal chamber; 6. An electricity meter according to claim 5 when dependent on claim 3 or 4.

7. said thermal device forming part of a circuit; the thermal device is configured to shut off the circuit if the temperature of the thermal device exceeds the temperature threshold; An electricity meter according to any one of claims 1 to 6.

8. the service switch is controlled to enable an electrical connection between the utility power line and the power meter when the circuit is closed, and to disable an electrical connection between the utility power line and the power meter when the circuit is interrupted; 8. The electricity meter of claim 7.

9. the power meter further comprising power meter electronics comprising a microprocessor; the thermal device forms a circuit with the microprocessor; 9. The electricity meter according to claim 7 or 8.

10. When a circuit between the microprocessor and the thermal device is interrupted, the microprocessor is configured to control the service switch to disable an electrical connection between the utility power line and the power meter.

10. The electricity meter of claim 9.

11. the power meter electronics are isolated from the thermal device by the base plate shroud; An electricity meter according to claim 9 or 10 when dependent on claim 3.

12. the thermal device forms a circuit with the service switch; the service switch is configured to disable an electrical connection between the utility power line and the power meter when the circuit is interrupted; 9. The electricity meter according to claim 7 or 8.

13. the base plate includes first and second blades, a first thermal device disposed adjacent to the first blade, and a second thermal device disposed adjacent to the second blade; An electricity meter according to one of claims 1 to 12.

14. the first and second thermal devices are attached to a base plate; 14. The electricity meter of claim 13.

15. The thermal device comprises a thermal fuse or a thermal switch. An electricity meter according to one of claims 1 to 14.

16. 1. A base plate for an electricity meter, comprising: the power meter is connected to a utility power line and a load via a meter mounting device and determines power consumption between the utility power line and the load; The base plate is at least one blade configured to couple to a corresponding jaw of the meter mounting device to electrically connect the electricity meter to the utility power line and the load; a thermal device disposed adjacent to the at least one blade, the thermal device configured to control a service switch to disable an electrical connection between the utility power line and the power meter when a temperature of the thermal device exceeds a temperature threshold. Base plate.

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