How do you know the voltages and plugs around the world? Why is there such a big difference?


Today, talk to you, talk about the voltage level and electrical plug model around the world!

First we understand some basic concepts;

one. The definition of the power: The power means the work made in the unit time, that is, the power is a physical quantity that is slow.


The formula of the feed rate is P = W / T P represents power, the unit is “wat”, referred to as “watt”, symbol is “W” W Representation, the unit is “Jouo”, referred to as “”, symbol is “J” T indicates time, the unit is “second”, the symbol is “s”

P = ui = u2 / r


two. Definition of the voltage: The potential difference between the two points is called two points.

Electrical engineering is called the cause of a current to form a current in the conductor.

The voltage is like water, and the water pressure can flow in a certain direction, then the voltage is a physical quantity that can be moved in a certain direction in a certain direction.

three. Current definition: The current means the directional movement of the charge.

The size of the current is called the current intensity (referred to as current, symbols I), refers to the amount of charge through a cross section of a wire within a unit time, and is called a “ampere” (a) per second.

Common units have milliamps (MA) and Micron (μA)

The conversion is: 1A = 1000 mA, 1 mA = 1000 μA.

Four. Definition of the resistor: is the size of the current flow barrier force. The unit of the resistor is ohm, indicated by symbol “Ω”.

Ohm definition: When a voltage of 1 volt is added to both ends of a resistor, if there is a 1 amps current in this resistor, the resistance is 1 ohm. In the international unit system, the unit of resistance is ω (ohm), and there is also KΩ (Qiano), MΩ (Mega). Among them: unit conversion 1MΩ = 1000kΩ, 1kΩ = 1000Ω.

Electrical classification

European household appliance safety standards total 0, 01, 1, class 2, 3 categories.

0 Class: This type of appliance requires only the charged portion to isolate the outer casing without grounding requirements. Such appliances are mainly used in people who are inseparable, such as fluorescent rectifiers.

01 Class 0: This type of electrical appliance has industrial insulation, and there is a ground endpoint to be grounded or not connected. It can be used in a dry environment (the chamber of the wooden floor), otherwise it should be grounded, such as electric iron, etc.

Category 1: There is a work insulation, there is a grounded endpoint and grounding line, which must be grounded. The grounding line must use the outer table as a yellow-green two-color copper core wire, and the contact resistance should not be more than 0.1 ohm. Such as electric oven, electric kettle, toast.

Category 2: This type of electrical appliance uses double insulation or strengthening insulation without grounding requirements. There are work insulated, there are still independent protection insulation or effective electrical isolation. This type of electrical appliance has a high degree of safety, which can be used to contact the human skin, and the double insulated flag is a “back” shape.

3: Use a safe voltage (50 volts below 50), such as razor and other electrical appliances. A secure voltage must be used in an environment that cannot be securely grounded and dry.

Classification of world voltages

Mainly two major categories:


Range of 100V-127V, representing countries and regions: USA, Canada Japan, etc.

Generally known as the US voltage 120V


The 220V-240V range, representing countries and regions: Germany, England, etc. EU countries, the Middle East, China, Russia and other countries and Hong Kong areas.

Generally referred to as the European voltage. 230V

power cable

one. Composition of power cord: plug, wire and corresponding identity

1. Classification:

Press the voltage: European plugs and decisons

Press the foot from the foot: two feet and three plugs

According to the shape of the plug: a lot of species, depending on the country,

see Attachment


2. Electrical parameters of the plug: the maximum rated current and

Voltage such as: Europe: 250V / 2.5A, 250V / 10A,

3. Logo of the plug:


European plug:

Certification marker: Plugs generally have Germany VDE, France NF, Netherlands Kema, Denmark DMKO, Switzerland Semko, Austria Ove, Finland Fi, Belgium Cebec and China CCC and other countries certification

Electrical parameters: such as 250V / 2.5A

US decision plug: certification mark: there is a US UL, Canada CSA, Japan, Taiwan and other certifications


Manufacturer model: such as Fe-122P

UL certification number: such as: E219959

electric wire


one. Wire classification:

1. Powering the voltage: European Line and USC

2. Press the material:

External insulation materials: PVC line, silicone

Line, rubber line, Teflon line, woven silicone rubber



3. Point copper core wire and aluminum core line according to the conductor material.

China power cord plug voltage: 220V 50Hz

China Power Cart Number Method

Power cord number: Insulated wires can be divided into single-strand line and multi-strand according to the divisions of each wire, usually the insulated wire of 6 square millimeters or more is multi-strand, 6 square millimeters and below insulated wires can be Single strand, can also be a multi-strand, we call 6 square millimeters and the following single strands called hard lines, and the multi-shaped line is called a cord. The hard wire is indicated by “B”, and the soft line is represented by “R”. The B series is classified into a cloth wire, so starting with B,

V is PVC polyvinyl chloride, that is, (PVC plastic) l is the meaning of the aluminum core R is (soft), to be soft, it is to increase the number of conductor. The main insulation material is polyvinyl chloride PVC and poly Both ethylene PE, polyvinyl chloride “V”, “V” is represented by “y”. The insulated wire is divided into a single core wire and a multi-core wire according to the number of insulated wires, which can be divided into single core wire and multi-core wire, and the multi-core wire can also be fixed in an insulated sheath. Multi-core wires in the same shelter can be more than 24 cores. Parallel multi-core wires are indicated by “B”, and the unmatched multi-core lines are indicated by “S”. It can be convenient to see the meaning of the wire model, as shown below:

Model Name


BV copper core PVC insulated wire; BLV aluminum core polyvinyl chloride insulated wire;

Polyvinyl chloride insulated PVC sheathed wire;

BLVV aluminum core polyvinyl chloride insulated polyvinyl chloride sheathed wire; BVR copper core PVC insulation cord;

RV copper core polyvinyl chloride insulation mounting cord;

RVB copper core polyvinyl chloride insulation flat cable flexible; BVS copper core PVC insulated mincede wiring; RVV copper core PVC insulated polyvinyl chloride sheathed soft line; BYR polyethylene insulated soft wire; BYVR Ethylene insulated polyvinyl chloride sheath cord;

RY polyethylene insulated cord;

RYV polyethylene insulated polyvinyl chloride sheathed cord

European power cord;

European Multi-Country: Israel Sii, United Kingdom BS, Australia Saa, Germany VDE / GS, France NF, Netherlands Kema, Denmark DMKO, Switzerland Semko, Austria Ove, Finland Fi, Belgium Cebec

American power cord

1.spt series is an overall insulation (only insulating layer)

SPT-1 18AWG / 2C 1 series is thinner for lightweight electrical appliances

SPT-2 18-16AWG / 2C 2 Series Insulation is thicker than 1 series,

Large power is lighter.

SPT-3: 18-14AWG 3 series is the thickest, used for high power appliances

HPN 16AWG / 2C (HPN is a rubber line)


The 2.NISPT series is non-integral insulation (ie insulating layer + sheath).


NISPT-1 20-18AWG / 2C

SJT: 18-14AWG / 3C SJTW: 18-14AWG / 3C SVT: 18-16AWG / 3C

Finally, I made a form for everyone to watch whether your wire is reached!