The effect of PWM frequency on the effectiveness of protection against electric shock using residual current devices

2010 ◽  
Author(s):  
Stanislaw Czapp
Keyword(s):  
Electric Shock ◽  
Residual Current

scholarly journals Testing Sensitivity of A-Type Residual Current Devices to Earth Fault Currents with Harmonics

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 2044
Author(s):  
Stanislaw Czapp
Keyword(s):  
Power Systems ◽  
Electric Shock ◽  
Low Voltage ◽  
Wide Spectrum ◽  
Residual Current ◽  
Motor Speed ◽  
Earth Fault ◽  
Fault Currents ◽  
Wide Range ◽  
Sinusoidal Waveform

In many applications, modern current-using equipment utilizes power electronic converters to control the consumed power and to adjust the motor speed. Such equipment is used both in industrial and domestic installations. A characteristic feature of the converters is producing distorted earth fault currents, which contain a wide spectrum of harmonics, including high-order harmonics. Nowadays, protection against electric shock in low-voltage power systems is commonly performed with the use of residual current devices (RCDs). In the presence of harmonics, the RCDs may have a tripping current significantly different from that provided for the nominal sinusoidal waveform. Thus, in some cases, protection against electric shock may not be effective. The aim of this paper is to present the result of a wide-range laboratory test of the sensitivity of A-type RCDs in the presence of harmonics. This test has shown that the behavior of RCDs in the presence of harmonics can be varied, including the cases in which the RCD does not react to the distorted earth fault current, as well as cases in which the sensitivity of the RCD is increased. The properties of the main elements of RCDs, including the current sensor, for high-frequency current components are discussed as well.

scholarly journals Development of a Range of Modified Multifunctional Residual Current Systems and Their Industrial Implementation

2022 ◽  
Vol 1211 (1) ◽  
pp. 012020
Author(s):  
O К Nikolsky ◽  
T M Khalina
Keyword(s):  
Electric Shock ◽  
New Technology ◽  
Residual Current ◽  
Leakage Currents ◽  
Fault Currents ◽  
Industrial Implementation ◽  
Industrial Use ◽  
Current Systems

Abstract The developments of the AltSTU have been reviewed in the area of creating a new technology for preventing technogenic hazards based on the residual current devices. The residual current devices are intended for protecting people from electric shock in case of contact with conductive parts of the electric appliances and shall facilitate reduction of fire risks caused by a prolonged flow of leakage currents and fault currents resulting from them. The results of creating different modifications of protective trip circuits and their industrial use are provided.

scholarly journals STUDI PROTEKSI ELECTRIC SHOCK PADA INSTALASI RUMAH TINGGAL MENGGUNAKAN RESIDUAL CURRENT CIRCUIT BREAKER WITH INTERGRAL OVERLOAD PROTECTION

2021 ◽  
Vol 6 (2) ◽  
pp. 70
Author(s):  
Sofyar Sofyar
Keyword(s):  
Electric Shock ◽  
Direct Contact ◽  
Research Method ◽  
Short Circuit ◽  
Circuit Breaker ◽  
Residual Current ◽  
Protection System ◽  
Current Sensitivity ◽  
A Value ◽  
Overload Protection

This paper offers a solution for securing a simple residential installation of the dangers of electric shock. In the introduction, the background of the importance of using a protection system in electrical installations is explained and some definitions related to electric shock and RCBO. For the part of the research method, the specifications of the RCBO used are displayed and the flow of the research is also shown. In the discussion and the results it is known that RCBO will trif if there is an overload, short circuit, and electric shock caused by direct contact with the live part. For nominal current (In) from RCBO, RCBO with a value of 6 Ampere and its current sensitivity (I∆n = 30 mA) is chosen according to the RCBO on the market.

scholarly journals Behavior of Residual Current Devices at Frequencies up to 50 kHz

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1785
Author(s):  
Stanislaw Czapp ◽  
Hanan Tariq
Keyword(s):  
Electric Shock ◽  
High Frequency ◽  
Pulse Width Modulation ◽  
Low Voltage ◽  
Residual Current ◽  
Indirect Contact ◽  
Additional Protection ◽  
Operating Current ◽  
Low Voltage Circuits ◽  
Frequency Components

The use of residual current devices (RCDs) is obligatory in many types of low-voltage circuits. They are devices that ensure protection against electric shock in the case of indirect contact and may ensure additional protection in the case of direct contact. For the latter purpose of protection, only RCDs of a rated residual operating current not exceeding 30 mA are suitable. Unfortunately, modem current-using equipment supplied via electronic converters with a pulse width modulation produces earth fault currents composed of high-frequency components. Frequency of these components may have even several dozen kHz. Such components negatively influence the RCDs’ tripping level and, hence, protection against electric shock may be ineffective. This paper presents the results of the RCDs’ tripping test for frequencies up to 50 kHz. The results of the test have shown that many RCDs offered on the market are not able to trip for such frequencies. Such behavior was also noted for F-type and B-type RCDs which are recommended for the circuits of high-frequency components. Results of the test have been related to the requirements of the standards concerning RCDs operation. The conclusion is that these requirements are not sufficient nowadays and should be modified. Proposals for their modification are presented.

scholarly journals Fatal electrical accidents in Finland 1980–2019 – trends and reducing measures

2020 ◽  
Vol 4 (2) ◽  
pp. 37-47
Author(s):  
Vesa Linja-aho
Keyword(s):  
Electric Shock ◽  
Death Rate ◽  
Power Line ◽  
Residual Current ◽  
Male Child ◽  
Electrical Safety ◽  
The Public ◽  
Overhead Power Line ◽  
Current Device

This paper analyses the content of fatal electrical accident records (n=157) in Finland during the years 1980–2019 in order to identify and classify accident types and causes. During the 40-year period, the death rate from electrical accidents has decreased from 0.29 per 100,000 people per year to 0.00-0.07 in the last decade. The number of accidents rooting from accidentally touching live parts and by making illegal electrical installations has plummeted. Of all fatalities, 37% could probably have been prevented if the circuit had been protected with a residual current device, which is now mandatory in new installations. The most common electrical accident in 2010–2019 was an electric shock from a railway overhead power line. Of fatal electrical accidents, 76% occur between April and September and 92.5% of victims are male. Child casualties are very rare. The level of electrical safety can be considered acceptable, but educating the public still has room for improvement.

Detection threshold for electric shock in psychopaths.

1968 ◽  
Vol 73 (3, Pt.1) ◽  
pp. 268-272 ◽  
Author(s):  
Robert D. Hare
Keyword(s):  
Electric Shock ◽  
Detection Threshold
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