Electric power meter including a temperature sensor and controller

• US 6,847,300 B2
• Filed: 01/17/2002
• Issued: 01/25/2005
• Est. Priority Date: 02/02/2001
• Status: Expired due to Fees

• Current Assignee: Motorola Solutions, Inc.
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Yee, David Moon, Zucarelli, Philip John, Wallis, David Richard, Keller, Theodore Woolley
• Primary Examiner(s): WONG, ALBERT KANG
• Application Number:
  US10/051,721
• Publication Number:
  US 20020105435A1
• Time in Patent Office: 1,104 Days
• Field of Search: 340/584, 340/588, 340/870.02, 340/870.17, 361/37, 361/103, 307/117
• US Class Current: 340/584
• CPC Class Codes: G01D 3/08 with provision for safeguarding the apparatus, e.g. against abnormal operation, against breakdown
• CPC Class Codes: H04Q 2209/30 using a wired architecture
• CPC Class Codes: H04Q 2209/60 for transmitting utility meters data, i.e. transmission of data from the reader of the utility meter
• CPC Class Codes: H04Q 2209/823 where the data is sent when the measured values exceed a threshold, e.g. sending an alarm
• CPC Class Codes: H04Q 9/02 Automatically-operated arrangements

Abstract

An electric power meter (102) includes a temperature sensor (114) and a controller (112). The controller (112) is operable, based on the temperature reported from the temperature sensor (114), to generate alarm(s) when the temperature exceeds certain alarm threshold(s) (307, 507, 508) and to activate a power disconnect switch (104), thereby shutting off power to a customer premises, when the temperature exceeds a shut off threshold (309, 509). The controller (112) is operable to activate the power disconnect switch (104) for non-payment of electricity cost, subject to secondary criteria based on regulatory requirements. A customer terminal (103) may be used to notify a customer of an alarm condition, to provide information regarding electrical power usage or to provide information regarding disconnection of electrical power.

Claims

1. A power meter comprising:

a temperature sensor;

a power disconnect switch; and

a controller operable to monitor the power meter temperature based on input from the temperature sensor, compare the power meter temperature to a shutoff threshold; and

activate the power disconnect switch if the power meter temperature exceeds the shutoff threshold.

2. The power meter of claim 1 wherein the controller is further operable to compare the power meter temperature to an alarm threshold, the alarm threshold being less than the shutoff threshold;

and generate an alarm if the power meter temperature exceeds the alarm threshold.

3. In combination, the power meter of claim 2 and a customer terminal, the customer terminal being adapted to notify a customer of the alarm if the power meter temperature exceeds the alarm threshold, the customer terminal comprising:

a terminal controller;

a display; and

a terminal communications interface electrically coupled to the terminal controller, the terminal communications interface being operable to exchange data with the power meter over a power line carrier.

4. The power meter of claim 1 wherein the controller is further operable to activate the power disconnect switch for non-payment of electricity cost.

5. The power meter of claim 4 wherein the controller is inhibited from activating the power disconnect switch for non-payment of electricity cost below a certain outdoor temperature.

6. The power meter of claim 4 wherein the controller is inhibited from activating the power disconnect switch for non-payment of electricity cost on certain dates.

7. The power meter of claim 4, further comprising a photo sensor for determining a level of ambient light outside of the power meter, the controller being inhibited from activating the power disconnect switch for non-payment of electricity cost below a certain level of ambient light outside of the power meter.

8. In an electric energy metering system including a power meter having a temperature sensor, a controller, and a power disconnect switch, a method comprising the controller performing steps of:

monitoring a power meter temperature reported to the controller from the temperature sensor;

comparing the power meter temperature to a shutoff threshold; and

activating the power disconnect switch if the power meter temperature exceeds the shutoff threshold.

9. The method of claim 8 further comprising the step of:

comparing the power meter temperature to an alarm threshold, the alarm threshold being less than the shutoff threshold; and

generating an alarm if the power meter temperature exceeds the alarm threshold, thereby defining an alarm condition.

10. The method of claim 9 wherein the electric energy metering system includes a customer terminal, the step of generating an alarm comprising alerting a customer of the alarm condition via the customer terminal.

11. The method of claim 9 further comprising:

when in the alarm condition, comparing the power meter temperature to an alarm reset threshold, the alarm reset threshold being less than the alarm threshold; and

deactivating the alarm, thereby defining a deactivated alarm condition, if the power meter temperature falls below the alarm reset threshold.

12. The method of claim 11 wherein the electric energy metering system includes a customer terminal, the step of deactivating the alarm comprising notifying a customer of the deactivated alarm condition via the customer terminal.

13. The method of claim 9, wherein the power meter includes a power measurement sensor, the method comprising:

when in the alarm condition, monitoring instantaneous power measured by the power measurement sensor;

determining a maximum instantaneous power measured by the power measurement sensor; and

if the instantaneous power falls a fixed percentage below the maximum instantaneous power, deactivating the alarm, thereby defining a deactivated alarm condition.

14. The method of claim 9, wherein the power meter includes a power measurement sensor, the method comprising:

when in the alarm condition, monitoring instantaneous power measured by the power measurement sensor;

determining a maximum instantaneous power measured by the power measurement sensor;

if the instantaneous power falls a fixed percentage below the maximum instantaneous power, deactivating the alarm, thereby defining a deactivated alarm condition; and

setting a variable alarm threshold, the variable alarm threshold corresponding to the power meter temperature when the instantaneous power has fallen the fixed percentage below the maximum instantaneous power; and

when in the deactivated alarm condition, comparing the power meter temperature to the variable alarm threshold; and

re-activating the alarm, thereby defining a re-activated alarm condition, if the power meter temperature rises above the variable alarm reset threshold.