Protective devices and methods for protection against electric shock in a power supply system having multiple power sources

Patent metadata

Field	Value
Publication number	US-2026088603-A1
Application number	US-202519335070-A
Country	US
Kind code	A1
Filing date	Sep 22, 2025
Priority date	Sep 23, 2024
Publication date	Mar 26, 2026
Grant date	—

Abstract

The present disclosure relates to protective devices and methods for protection against electric shock in an AC, 3AC or DC power supply system, which has a main supply and additional power sources. In a first embodiment, a voltage measuring device is switched at each of the additional power sources. A signaling device disposed at the additional power sources signals when a voltage is exceeded by means of a disconnect signal should the measured voltage exceed a voltage threshold at the corresponding additional power source. A second embodiment comprises a residual current device disposed at each of the additional power sources and intended for identifying a corresponding residual differential current, and a measuring impedance switched at the additional power sources and intended for generating the residual differential current.

First claim

What is claimed is:

1 . A protective device for protection against electric shock in an AC, 3AC or DC power supply system comprising a main supply and additional power sources, an N conductor or an M conductor being connected to a protective conductor (PE) with low resistance at the main supply, the protective device comprising:
a voltage measuring device switched between the N conductor or M conductor and the protective conductor (PE) at each of the additional power sources and configured to measure an N-conductor-to-protective-conductor voltage (U N-PE ) or an M-conductor-to-protective-conductor voltage (U M-PE ); and a signaling device disposed at each of the additional power supplies and configured to signal when a voltage has been exceeded via a disconnect signal when the N-conductor-to-protective-conductor voltage (U N-PE ) or the M-conductor-to-protective-conductor voltage (U M-PE ) exceeds a voltage threshold at a corresponding one of the additional power supplies.

2 . The protective device according to claim 1 , further comprising:
a disconnect device disposed at each of the additional power supplies and is connected to the corresponding signaling device in order to receive the disconnect signal.

3 . A protective device for protection against electric shock in an AC, 3AC or DC power supply system comprising a main supply and additional power sources, an N conductor or an M conductor being connected to a protective conductor (PE) with low resistance at the main supply, the protective device comprising:
a residual current device (RCD 2 ) disposed at each of the additional power sources and configured to identify a corresponding residual differential current (I dF ), wherein a measuring impedance switched between the N conductor or the M conductor and the protective device at each of the additional power sources and configured to generate the residual differential current (I dF ) caused by an N-conductor-to-protective-conductor voltage (U N-PE ) or an M-conductor-to-protective-conductor voltage (U M-PE ).

4 . The protective device according to claim 3 , wherein the measuring impedance and a protective-conductor connection are integral components of the residual-current device (RCD 2 ).

5 . The protective device according to claim 3 , wherein the measuring impedance is greater than a fault-loop impedance and less than a quotient derived from an admissible touch voltage (U B ) and a nominal tripping current of the residual current device (RCD 2 ).

6 . The protective current device according to claim 3 , wherein a time-slot control cyclically activates the measuring impedances in temporal intervals.

7 . A method for protection against electric shock in an AC, 3AC or DC power supply system having a main supply and additional power sources, an N conductor or an M conductor being connected to a protective conductor (PE) with low resistance at the main supply, the method comprising:
measuring an N-conductor-to-protective-conductor voltage (U N-PE ) or an M-conductor-to-protective-conductor voltage (U M-PE ) via a voltage measuring device switched between the N conductor or the M conductor and the protective conductor (PE); and signaling when a voltage is exceeded via a disconnect signal via a signaling device disposed at each of the additional power sources when the N-conductor-to-protective-conductor voltage (U N-PE ) or the M-conductor-to-protective-conductor voltage (U M-PE ) exceeds a voltage threshold at the respective additional power source.

8 . The method according to claim 7 , further comprising disconnecting the corresponding additional power source via a disconnect device disposed at each of the additional power sources and connected to the corresponding signaling device to receive the disconnect signal.

9 . A method for protection against electric shock in an AC, 3AC or DC power supply system having a main supply and additional power sources, an N conductor or an M conductor being connected to a protective conductor (PE) with low resistance at the main supply, the method comprising:
generating a residual differential current (I dF ) caused by an N-conductor-to-protective-conductor voltage (U N-PE ) or an M-conductor-to-protective-conductor voltage (U M-PE ) via a measuring impedance ( 31 ) switched between the N conductor or the M conductor and the protective conductor (PE) at the corresponding additional power sources; and disconnecting the additional power source via a residual current device (RCD 2 ) disposed at the corresponding additional power sources and intended for identifying the corresponding residual differential current (I dF ).

10 . The method according to claim 9 , wherein the residual differential current (I dF ) is generated with the measuring impedance, and wherein the measuring impedance and a protective-conductor connection are integral components of the residual current device (RCD 2 ).

11 . The method according to claim 9 , wherein the residual differential current (I dF ) is generated with the measuring impedance which is greater than a fault-loop impedance and less than a quotient derived from an admissible touch voltage and a nominal tripping current of the residual current device (RCD 2 ).

12 . The method according to claim 9 , further comprising cyclically activating the measuring impedances in temporal intervals via a time-slot control.

Assignees

• Bender Gmbh & Co Kg

Inventors

• Hackl Dieter
• Haub Dennis

Classifications

• H02H3/093

  with timing means {(in general H02H3/027; thermal delay H02H3/085; timing means for undervoltage protection H02H3/247)} · CPC title

• H02H3/006

  Calibration or setting of parameters · CPC title

• H02H1/0007

  concerning the detecting means (in general G01R or other subclasses of G01; reed switches H01H71/2445) · CPC title

• H02H5/10

  responsive to mechanical injury, e.g. rupture of line, breakage of earth connection · CPC title

• H02H3/16

  responsive to fault current to earth, frame or mass (with balanced or differential arrangement H02H3/26 {; monitoring earth connection H02H5/105}) · CPC title