Method for switching off an arc in an electrical installation

Patent metadata

Field	Value
Publication number	US-11502500-B2
Application number	US-201716467505-A
Country	US
Kind code	B2
Filing date	Dec 1, 2017
Priority date	Dec 9, 2016
Publication date	Nov 15, 2022
Grant date	Nov 15, 2022

Abstract

An electrical installation includes: a switchgear cabinet; a protective switch arranged in the switchgear cabinet; at least one optical triggering device which is operatively connected to the protective switch and for triggering or switching off the protective switch upon optical detection of an arc; a detection device for detecting an access or an access request to a secured area of the electrical installation by detecting a presence of the at least one optical triggering device in a danger area of the electrical installation; and an electronic circuit which is connected to the detection device and allows, and otherwise prevents, a triggering or switching off of the protective switch by the at least one optical triggering device upon detection of the access or the access request, when the at least one optical triggering device is present in the danger area.

First claim

The invention claimed is:

1. An electrical installation, comprising:
a switchgear cabinet;
a protective switch arranged in the switchgear cabinet;
at least one optical triggering device which is operatively connected to the protective switch and configured to trigger or switch off the protective switch upon optical detection of an arc;
a detection device configured to detect an access to a secured area of the electrical installation by detecting a presence of the at least one optical triggering device in a danger area of the electrical installation;
an electronic circuit which is connected to the detection device and is configured to allow, and otherwise prevent, a triggering or switching off of the protective switch by the at least one optical triggering device when the at least one optical triggering device is present in the danger area;
an operating current measuring device configured to measure a current flowing through the protective switch or the electric installation; and
a further electronic circuit which is connected to the operating current measuring device and is configured to trigger or switch off the protective switch by the at least one optical triggering device only when an operating current threshold value is exceeded by a measured operating current and when an increase threshold value of a time derivative of the measured operating current is exceeded, wherein:
the operative connection between the protective switch and the at least one optical triggering device and/or between the protective switch and the voltage measuring device/current measuring device is made wireless,
the detection device is formed in the danger area of the electrical installation and the electronic circuit connected to the detection device is configured to allow, and otherwise prevent, a triggering or switching off of the protective switch by the at least one triggering device when the at least one optical triggering device is present in the danger area, and
the detection device comprises a wireless detection receiver or is connected to a wireless detection receiver and configured to detect the at least one optical triggering device as present in a danger area, when a transmit signal generated by the at least one optical triggering device causes a reception field strength in the detection receiver which lies above a field strength threshold value.

2. The electrical installation according to claim 1 , wherein the electronic circuit is configured as a logical AND operation of a positive arc signal of the at least one optical triggering device and an access signal of the detection device, and is operatively connected to the protective switch on an output side.

3. The electrical installation according to claim 1 , wherein the protective switch has a switching input configured to trigger or switch off the protective switch,
wherein the at least one optical triggering device has a control output which is connected to a switching input of the protective switch, and
wherein the at least one optical triggering device is configured to change a state of the control output upon detection of an arc and to subsequently trigger or switch off the protective switch.

4. The electrical installation according to claim 1 , wherein the protective switch comprises a line protective switch, an arc short-circuit switch, or a combined line and arc short-circuit switch.

5. The electrical installation according to claim 1 , wherein
d) the at least one optical triggering device is configured to be attached to a human body, or
e) the at least one optical triggering device is arranged in the switchgear cabinet or outside the switchgear cabinet, or
f) a first optical triggering device is configured to be attached to the human body, and a second optical triggering device is arranged in the switchgear cabinet or outside the switchgear cabinet.

6. The electrical installation according to claim 5 , wherein the at least one optical triggering device is arranged on a helmet, an armband, and/or on an article of clothing.

7. The electrical installation according to claim 5 , wherein
the electrical installation comprises g) two measuring electrodes with a voltage measuring device arranged in between and configured to measure a voltage lying between the measuring electrodes, and/or h) two measuring electrodes with a current measuring device arranged in between configured to measure a current flowing between the measuring electrodes, and/or i) an article of clothing with electrical conductors and a current measuring device configured to measure a current flowing through the electrical conductors,
wherein the voltage measuring device/current measuring device is operatively connected to the protective switch, and
wherein the voltage measuring device/current measuring device is configured to trigger or switch off the protective switch upon detection of a measured value lying above a threshold value.

8. The electrical installation according to claim 7 , wherein the measuring electrodes in cases g) and h) are configured to be attached to a human body.

9. The electrical installation according to claim 8 , wherein one electrode is arranged on one armband/leg band each, or
wherein both measuring electrodes are arranged at a distance from each other on a single armband/leg band.

10. The electrical installation according to claim 7 , wherein
the electrical installation in case h) has one current measuring resistor electrically connected to the measuring electrodes, and/or in case i) has a current measuring resistor connected to the electrical conductors of the article of clothing, and in both cases has a voltage measuring device configured to measure an electrical current drop at the current measuring resistor, and/or
the current measuring device has a push-through converter configured to measure an electromagnetic field which in case h) is generated by a current flowing between the measuring electrodes, and in case i) is generated by a current flowing through the electrical conductors of the article of clothing.

11. The electrical installation according to claim 7 , wherein in case i), the electrical conductors provided in the article of clothing comprise electrically conductive wires, an electrically conductive mesh, and/or an electrically conductive foil.

12. The electrical installation according to claim 7 , wherein one of the two measuring electrodes in cases g) and h) is connected to a ground potential, or a ground electrode is provided which is connected to a ground potential and which is configured to be attached to the human body, and/or in case i), the electrical conductors of the article of clothing are connected to a ground potential.

13. The electrical installation according to claim 12 , wherein the ground electrode is arranged on an armband or a leg band.

14. The electrical installation according to claim 7 , wherein the measuring electrodes and/or the ground electrode are arranged inside an article of clothing.

15. The electrical installation according to claim 7 , wherein the article of clothing comprises a glove, jacket, overalls, pants, or protective suit.

16. The electrical installation according to claim 1 , wherein a control output of the at least one optical triggering device and/or the voltage measuring device/current-measuring device is configured as a wireless transmitter or is connected to a wireless transmitter,
wherein a switching input of the protective switch is configured as a wireless receiver or is connected to a wireless receiver, and
wherein the wireless transmitter and the wireless receiver are configure

Assignees

• Eaton Intelligent Power Ltd

Inventors

• Reuberger Georg

Classifications

• H01H83/20

  operated by excess current as well as by some other abnormal electrical condition · CPC title

• H02B1/306

  Accessories, e.g. windows · CPC title

• H02H5/12

  responsive to undesired approach to, or touching of, live parts by living beings · CPC title

• H01H9/50

  Means for detecting the presence of an arc or discharge · CPC title

• G01V3/08

  operating with magnetic or electric fields produced or modified by objects or geological structures or by detecting devices (with electromagnetic waves G01V3/12) · CPC title