GB2499690A - Warning of a current or voltage above a threshold on a metallic pipe - Google Patents

Warning of a current or voltage above a threshold on a metallic pipe Download PDF

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Publication number
GB2499690A
GB2499690A GB1218622.7A GB201218622A GB2499690A GB 2499690 A GB2499690 A GB 2499690A GB 201218622 A GB201218622 A GB 201218622A GB 2499690 A GB2499690 A GB 2499690A
Authority
GB
United Kingdom
Prior art keywords
current
voltage
alarm
pipe
exceeded
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
GB1218622.7A
Other versions
GB2499690B (en
GB201218622D0 (en
Inventor
Guy Bertrand
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Scotia Gas Networks Ltd
Original Assignee
Scotia Gas Networks Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Scotia Gas Networks Ltd filed Critical Scotia Gas Networks Ltd
Publication of GB201218622D0 publication Critical patent/GB201218622D0/en
Publication of GB2499690A publication Critical patent/GB2499690A/en
Application granted granted Critical
Publication of GB2499690B publication Critical patent/GB2499690B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R1/00—Details of instruments or arrangements of the types included in groups G01R5/00 - G01R13/00 and G01R31/00
    • G01R1/02—General constructional details
    • G01R1/06—Measuring leads; Measuring probes
    • G01R1/067—Measuring probes
    • G01R1/06788—Hand-held or hand-manipulated probes, e.g. for oscilloscopes or for portable test instruments
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
    • F17D—PIPE-LINE SYSTEMS; PIPE-LINES
    • F17D5/00—Protection or supervision of installations
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
    • G01R19/145—Indicating the presence of current or voltage
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
    • G01R19/165—Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
    • G01R19/165—Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values
    • G01R19/16533—Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values characterised by the application
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R15/00—Details of measuring arrangements of the types provided for in groups G01R17/00 - G01R29/00, G01R33/00 - G01R33/26 or G01R35/00
    • G01R15/12—Circuits for multi-testers, i.e. multimeters, e.g. for measuring voltage, current, or impedance at will

Abstract

A current or a voltage present on a metallic pipe such as a gas pipe is detected by an apparatus comprising a current sensor 1, a voltage sensor 2 and an alarm comprising warning lamps 5, 7 and audible buzzers 6, 8. The apparatus may clip onto the pipe. If the detected current or voltage exceeds a predetermined threshold, the alarm is activated. The apparatus is used to detect an excess current or voltage on a metal pipe and warn that the pipe presents an electric shock hazard e.g. because the pipe is live due to unintentional contact with an electricity source.

Description

Title: A Method and Apparatus for Detecting when a Current and/or Voltage has exceeded a
Predetermined Level
The present invention relates to a method and apparatus for detecting when a current and/or voltage has exceeded a predetermined level.
Gas is supplied to and in domestic premises by electrically conductive gas service and installation pipes which may be of steel or copper. These pipes may accidentally become electrically live as a result of unintended contact with a source of electricity. Consequently workmen working on these pipes to effect maintenance and/or a repair may receive a painful electric shock if the current and/or voltage on the pipe is above a harmful level.
It is therefore an object of the present invention to provide a method and apparatus whereby an indication is provided that the current and/or voltage has exceeded a predetermined level.
According to one aspect of the present invention we provide a method for detecting when a current and/or voltage has exceeded a predetermined level, the method comprising sensing the current and/or voltage and when the current and/or voltage has exceeded the predetermined level activating an alarm to provide an indication that the current and/or voltage has been exceeded.
Preferably the voltage appears across an insulated section.
Suitably the insulated section has an insulation joint and/or other electrical resistance in the electrical path to earth.
Conveniently the current flows when an insulated section is ineffective as an insulator or is not present.
Preferably the alarm is a visual alarm.
Suitably the alarm is an audible alarm.
Conveniently the current flows through a conductor.
Preferably a voltage with respect to earth is present on the conductor.
Suitably the conductor is a metallic pipe.
Conveniently the pipe is a pipe carrying gas particularly natural gas.
According to another aspect of the present invention we provide apparatus for detecting when a current and/or voltage has exceeded a predetermined level, the apparatus comprising means for sensing the current and/or means for sensing the voltage and means
for activating an alarm when the current has exceeded the predetermined level and/or . means for activating an alarm when the voltage has exceeded a predetermined level.
Preferably the alarm is a visual alarm.
*
Suitably alarm is an audible alarm.
Conveniently the apparatus is adapted to be attached to a conductor.
Preferably the conductor is a metallic pipe and current is caused to flow through the pipe and also gives rise to a voltage.
Suitably the pipe is a pipe carrying gas particularly natural gas.
Conveniently the apparatus is portable.
Preferably the apparatus has a housing for housing a battery to supply power to the apparatus.
Suitably the housing houses the sensing means and the alarm or alarms.
An embodiment of the invention will now be particularly described with reference to the accompanying drawings in which:
Figure 1 is a schematic block circuit diagram of the components of the apparatus and
Figure 2 is a schematic side view of the external casing of the apparatus and
Figure 3 is a schematic top view of the external casing of the apparatus and
Figure 4 is a schematic block circuit diagram similar to that shown in Figure 1.
Referring to Figure 1, the apparatus comprises a current sensor 1, a voltage sensor 2, a trip switch 3 for the current sensor, a trip switch 4 for the voltage sensor, a warning lamp 5 activated by the current trip switch 3, a buzzer 6 activated by the current trip switch 3, a warning lamp 7 activated by the voltage trip switch 4, a buzzer 8 activated by the voltage trip switch 4, a battery 9 for supplying power to the sensors 1 and 2, to trip switches 3 and 4, lamps 5 and 6 and buzzers 7 and 8, a flashlight 10 for enabling the workman to see the pipe and a switch 12 for switching the apparatus on or off and a switch 11 for independently switching the flashlight on and off. While the pipe to which the apparatus is attached in use would usually be a gas service pipe, it could also be a water pipe or even an oil pipe or indeed any other item or items containing a conductive path to which the apparatus can be attached. The section could be an insulated section with an insulation joint and/or other section with electrical resistance in the electrical path to earth. In this case the current flows when an insulated section is ineffective as an insulator or is not present.
The current sensor 1 receives power from the battery 9 to enable sensor 1 to measure the current in the pipe, and signals to the trip switch 3 if the measured current is sufficient to trip the switch. Switch 3 can only be tripped when the electric current flowing in the pipe (not shown) is above the predetermined/set value. When the switch 3 is tripped a current is allowed to flow to the warning lamp 5 which is illuminated and the buzzer 6 which provides an audible signal. Thus the workman is warned not to touch the pipe. Similarly the voltage sensor 2 measures the voltage on the pipe but this is insufficient to trip the trip switch 4 until the voltage exceeds the predetermined level. When the voltage exceeds the predetermined level the trip switch 4 allows a current to flow to the warning lamp 7 which is illuminated and to the buzzer 8 which emits an audible signal. The workman is therefore warned not to touch the pipe.
Referring to Figures 2 and 3 the casing or housing comprises a hollow tube 13 with a compartment at one end 14 to house the flashlight, a central compartment 15 to house the battery and all the circuitry except for the voltage sensor 2 which is housed in a compartment 16 at the other end of the housing. The housing is portable so that the apparatus can be moved to different sites to be tested as desired. The housing is provided with an external clip, clip 17, which may also form part of the current sensor 1, and for clipping or attaching the housing to the wall of the pipe.
Referring to Figure 4 the circuit diagram is almost identical to that of Figure 1 and identical components bear identical reference numbers. However a separate power line is provided to provide power from the battery 9 directly to the current trip switch 3 and directly to the voltage trip switch 4 as well as via the current sensor 1 in respect of the current trip switch 3 and via the voltage sensor 2 in respect of the voltage trip switch 4.
Should there be a stray current in the pipe for any reason, this will be transmitted through the wall of the casing and be picked up by the current sensor 1. If the current exceeds the predetermined level it will cause switch 3 to trip and allow current to flow to the warning lamp 5 and to the buzzer 6. Likewise, should there be a stray voltage on the pipe for any reason, this will be transmitted through the wall of the casing and be picked up by the voltage sensor 2. If the voltage exceeds the predetermined level warning lamp 7 and the buzzer 8 will be activated by a current flow from the switch. The workman will then cease working when any lamp or buzzer is activated until the electrical fault has been attended to. The current and the voltage sensors can work independently of each other.
When the switch 12 is on, an additional circuit (not shown) can be used to regularly pulse the buzzers 6 and 8 to inform the user that the unit is operating. This will also remind the user to switch the item off when not needed to save battery life.
3

Claims (21)

Claims
1. A method for detecting when a current and/or voltage has exceeded a predetermined level, the method comprising sensing the current and/or voltage and when the current and/or voltage has exceeded the predetermined level activating an alarm to provide an indication that the current and/or voltage has been exceeded.
2. A method as claimed in claim 1 in which the voltage appears across an insulated section.
3. A method as claimed in claim 2 in which the insulated section has an insulation joint and/or other electrical resistance in the electrical path to earth.
4. A method as claimed in any of the preceding claims in which the current flows when an insulated section is ineffective as an insulator or is not present.
5. A method as claimed in any of the preceding claims in which the alarm is a visual alarm.
6. A method as claimed in any of the preceding claims in which the alarm is an audible alarm.
7. A method as claimed in any of the preceding claims in which the current flows through a conductor.
8. A method as claimed in claim 7 in which a voltage with respect to earth is present on the conductor.
9. A method as claimed in claim 8 in which the conductor is a metallic pipe.
10. A method as claimed in claim 9 in which the pipe is a pipe carrying gas particularly natural gas.
11. Apparatus for detecting when a current and/or voltage has exceeded a predetermined level, the apparatus comprising means for sensing the current and/or means for sensing the j voltage and means for activating an alarm when the current has exceeded the ** predetermined level and/or means for activating an alarm when the voltage has exceeded a •J predetermined level.
••
12. Apparatus as claimed in claim 11 which the alarm is a visual alarm.
• •
•
13. Apparatus as claimed in claim 11 or claim 12 in which the alarm is an audible alarm.
•
.!
14. Apparatus as claimed in any of claims 11 to 13 in which the apparatus is adapted to be attached to a conductor.
15. Apparatus as claimed in claim 11 in which the conductor is a metallic pipe and current is caused to flow through the pipe and also gives rise to a voltage.
4
16. Apparatus as claimed in claim 15 in which the pipe is a pipe carrying gas particularly ' natural gas.
17. Apparatus as claimed in any of claims 11 to 16 in which the apparatus is portable.
18. Apparatus as claimed in any of claims 11 to 17 in which the apparatus has a housing for housing a battery to supply power to the apparatus.
19. Apparatus as claimed in claim 18 in which the housing houses the sensing means and the alarm or alarms.
20. A method substantially as hereinbefore described with reference to the drawings.
21. Apparatus substantially as hereinbefore described with reference to the drawings.
5
GB1218622.7A 2012-02-26 2012-10-16 A method and apparatus for detecting when a current and/or voltage has exceeded a predetermined level Active GB2499690B (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GBGB1203376.7A GB201203376D0 (en) 2012-02-26 2012-02-26 A method and apparatus for detectong when a current and/or voltage has exceeded a predetermined level

Publications (3)

Publication Number Publication Date
GB201218622D0 GB201218622D0 (en) 2012-11-28
GB2499690A true GB2499690A (en) 2013-08-28
GB2499690B GB2499690B (en) 2014-08-06

Family

ID=45991798

Family Applications (2)

Application Number Title Priority Date Filing Date
GBGB1203376.7A Ceased GB201203376D0 (en) 2012-02-26 2012-02-26 A method and apparatus for detectong when a current and/or voltage has exceeded a predetermined level
GB1218622.7A Active GB2499690B (en) 2012-02-26 2012-10-16 A method and apparatus for detecting when a current and/or voltage has exceeded a predetermined level

Family Applications Before (1)

Application Number Title Priority Date Filing Date
GBGB1203376.7A Ceased GB201203376D0 (en) 2012-02-26 2012-02-26 A method and apparatus for detectong when a current and/or voltage has exceeded a predetermined level

Country Status (1)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111833574A (en) * 2020-07-14 2020-10-27 广东格美淇电器有限公司 Voltage induction type alarm device and alarm method thereof

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3699432A (en) * 1970-06-25 1972-10-17 Environment Metrology Corp Electrical shock hazard detection system with station scanning and indicating means
US4398188A (en) * 1981-10-07 1983-08-09 Feigal Donn L Ground circuit voltage detector
GB2288667A (en) * 1994-04-19 1995-10-25 Wire Watcher Co Ltd Voltage detector
GB2310728A (en) * 1996-02-29 1997-09-03 Lloyd Jones David Voltage detection and alarm device
US5684466A (en) * 1995-09-12 1997-11-04 The Charles Machine Work, Inc. Electrical strike system control for subsurface boring equipment
US5952820A (en) * 1996-02-16 1999-09-14 Thrasher; M. D. Foreign voltage detector
US20070120694A1 (en) * 2005-11-30 2007-05-31 Caterpillar Inc. High voltage detection system
US20070159739A1 (en) * 2002-03-28 2007-07-12 Onachilla Michael D Voltage Sensing Hand Tool
US20090128348A1 (en) * 2007-11-20 2009-05-21 Hsu Kang-Neng Overload alarm device and method thereof

Family Cites Families (4)

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Publication number Priority date Publication date Assignee Title
US3831160A (en) * 1973-10-01 1974-08-20 Gen Electric Voltage and current monitoring system
US4862142A (en) * 1987-10-26 1989-08-29 Knight Eldon L Circuit with memory for detecting intermittent changes in resistance, current, voltage, continuity, power interruption, light, and temperature
ITLU20080013A1 (en) * 2008-08-14 2008-11-13 Giovanni Pieri SAFETY SYSTEM FOR ELECTRICITY SUPPLY TO SINGLE OR MULTIPLE LIVING UNITS (PARTICULARLY PART OF MULTI-STOREY BUILDINGS), TO AVOID THAT HAZARDOUS CONTACT VOLTAGES CAN BE HAVING ON THE GENERAL NODE
US20110313583A1 (en) * 2010-06-22 2011-12-22 Unified Packet Systems Corp. Integrated Wireless Power Control Device

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3699432A (en) * 1970-06-25 1972-10-17 Environment Metrology Corp Electrical shock hazard detection system with station scanning and indicating means
US4398188A (en) * 1981-10-07 1983-08-09 Feigal Donn L Ground circuit voltage detector
GB2288667A (en) * 1994-04-19 1995-10-25 Wire Watcher Co Ltd Voltage detector
US5684466A (en) * 1995-09-12 1997-11-04 The Charles Machine Work, Inc. Electrical strike system control for subsurface boring equipment
US5952820A (en) * 1996-02-16 1999-09-14 Thrasher; M. D. Foreign voltage detector
GB2310728A (en) * 1996-02-29 1997-09-03 Lloyd Jones David Voltage detection and alarm device
US20070159739A1 (en) * 2002-03-28 2007-07-12 Onachilla Michael D Voltage Sensing Hand Tool
US20070120694A1 (en) * 2005-11-30 2007-05-31 Caterpillar Inc. High voltage detection system
US20090128348A1 (en) * 2007-11-20 2009-05-21 Hsu Kang-Neng Overload alarm device and method thereof

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111833574A (en) * 2020-07-14 2020-10-27 广东格美淇电器有限公司 Voltage induction type alarm device and alarm method thereof

Also Published As

Publication number Publication date
GB2499690B (en) 2014-08-06
GB201203376D0 (en) 2012-04-11
GB201218622D0 (en) 2012-11-28

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