Electrical safety term 1
1 basic concepts
1.1
Security
Fail-safe
Performance designed to prevent dangerous failure of the product itself.
1.2
normal status
Normal condition
All facilities used to prevent danger are in a state of no damage.
1.3
Electrical accident
Electric accident
The destruction of building facilities, electrical equipment, human and animal casualties, and events that cause fires and explosions, directly or indirectly, caused by currents, electromagnetic fields, lightning, static electricity, and certain circuit failures.
1.4
Electric shock
electric shock
Electric shock
The pathological and physiological effects of current flow through the human or animal body.
1.5
Electromagnetic field damage
Injury due to electromagnetic field
The human body absorbs the energy damage caused by the electromagnetic field.
1.6
Destructive discharge
Dielectric breakdown
Destroyive discharge
Dielectric breakdown
Solids, liquids, gases and combinations of media under high voltage, the loss of dielectric strength phenomenon. During a destructive discharge, the voltage across the electrodes rapidly drops to zero or approaches zero.
1.7
Short circuit
Short circuit
  A connection between two points or points under different voltages in a circuit, accidentally or intentionally, by a relatively small resistance or impedance.
1.8
Insulation fault
Insulation fault
  Insulation resistance does not drop normally.
1.9
Ground Fault
Earth fault
Fault caused by the conductor being connected to ground or the insulation resistance to ground becoming less than a specified value.
1.10
Overcurrent
Overcurrent
Current exceeding rated current
1.11
Overvoltage
The voltage exceeding the rated voltage.
Overvoltage
1.12
Overload
Overload
Loads that exceed the rated load
1.13
Conductive section
Conductive part
Conductive, but not necessarily part of the operating current
1.14
Live parts
Live part
Conductor or conductive part that is energized during normal use. It includes a neutral conductor, but conventionally does not include a protective neutral conductor (PEN conductor)
1.15
Exposed conductive part
Exposed conductive parts
An electrically conductive part that can be touched by electrical equipment. It is not charged when it is normal, but it may be charged in the event of a fault.
Note: In the event of a fault, the conductive part of an electrical device that is exposed through the exposed conductive parts is not considered to be exposed conductive parts.
1.16
External conductive part
Extraneous conductive part
Electrically conductive parts that are not part of an electrical device and that tend to introduce electrical potential (usually ground potential).
1.17
At the same time touchable part
Can
A conductor or conductive part that a person can touch at the same time, or a conductor or conductive part that an animal can touch at the same time in some places.
Note: At the same time the accessible part can be:
(1) Live parts;
(2) Exposed conductive parts;
(3) External conductive parts;
(4) Protection conductors;
(5) Grounding electrode;
1.18
direct contact
Direct contact
Human or animal contact with live parts.
1.19
Indirect contact
Touch voltage
Human or animal contact with live exposed conductive parts under fault conditions
1.20
Contact voltage
Touch voltage
When the insulation is damaged, the voltage appearing between the parts can be touched at the same time.
Note: (1) As usual, this term is used only in relation to indirect contact protection
  (2) In some cases, the contact voltage value may be significantly affected by the impedance of the person touching these parts.
1.21
Step voltage
Step voltage
People stand on the earth where current flows, plus the voltage between the two feet.
1.22
Safety Extra Low Voltage
Safety extra-low voltage
(SELV)
In a circuit isolated from a supply mains by a safety isolating transformer or a converter with separate windings, the AC voltage between conductors or between any conductor and earth shall not exceed 50 volts.
1.23
Ground voltage
Voltage to earth
Potential difference between charged body and ground (ground potential is zero).
1.24
Overvoltage
Overvoltage to earth
Above the normal ground-peak voltage (corresponding to the highest system voltage), the voltage to ground in terms of the peak voltage.
1.25
Electric current
Shock current
Through the human or animal body and have currents that may cause pathological, physiological effects.
1.26
Perceptual current
Threshold of perception current
Under given conditions, the current through the body can cause any sensational minimum current value.
1.27
Get rid of current
Threshold of let-go current
The maximum current that a person holding the electrode can get out of under the given conditions.
1.28
Chattering current
Threshold of ventricular fibrillation current
The minimum current that causes ventricular fibrillation under given conditions.
1.29
Fault current
Fault current
Current caused by insulation damage or short circuited insulation.
1.30 ( circuit) overload current
1.31 Short-circuit current
Short-circuit current
In a circuit, an overcurrent occurs when a short circuit occurs due to a fault.
1.32 residual current
Residual current
The algebraic sum of the instantaneous value of the current flowing through all the live conductors in the circuit at one point of the electrical device.
1.33
Total body impedance
Total impedance of the human body
The vector sum of human body impedance and skin impedance.
1.34
Safety impedance
Safety
The impedance connected between the live part and the accessible conductive part, whose value can limit the current to a safe value in the normal use of the equipment and possibly failure, and maintain its reliability throughout the life of the equipment.
1.35
Fault tolerance
Fault withstandability
The ability of an electrical device to withstand the effects of a specified electrical fault current does not exceed the specified degree of damage.
1.36
Unsafe temperature
Unsafe temperature
Temperatures that may cause combustion and/or may cause the operator to perform unintended dangerous actions.