Class 0 to Class 3: A Detailed Overview

As someone deeply involved in the appliance manufacturing industry, I find it crucial to understand and adhere to the European safety standards for household appliances. These are categorized into five classes: Class 0, Class 01, Class 1, Class 2, and Class 3.

• Class 0: These appliances only need isolation of the live part from the shell. They don’t require grounding and are typically used in non-accessible areas.
• Class 01: These come with industrial insulation and grounding endpoints. Suitable for dry indoor environments, they can be used ungrounded on wooden floors. Elsewhere, grounding is necessary.
• Class 1: These appliances have working insulation and grounding endpoints. They must be grounded using a copper-core wire with a yellow-green bicolor appearance, ensuring the contact resistance is no more than 0.1 ohms.
• Class 2: Known for their double insulation or reinforced insulation, these don’t require grounding. They’re ideal for appliances in direct contact with human skin, indicated by a “back” shaped mark.
• Class 3: These are low-voltage appliances (below 50V) that can’t be safely grounded. They’re used in non-dry environments and must operate on a safety voltage.

The World of Voltage: 100V-127V and 220V-240V

Globally, voltage is divided into two main categories: 100V-127V and 220V-240V. The former, often referred to as the United States voltage, includes regions like the USA, Canada, Japan, and Taiwan. The latter, commonly known as the European voltage, covers Germany, the UK, other EU countries, the Middle East, China, Russia, and more.

• 100V-127V represents these countries and regions: the United States, Canada, Japan, and Taiwan. We usually call the United States voltage, 120V.
• 220V-240V represents these countries and regions: Germany, the United Kingdom, other EU countries, the Middle East, China, Russia, other countries, and Hong Kong. We usually call the European voltage, 230V.

Power Cord Essentials

Power cords, a pivotal component in our products, consist of plugs, wires, and specific markings. They vary by voltage (European or U.S. standard) and type (two-prong or three-prong). Each plug is designed to withstand a certain voltage and current.

Plug classification

• According to the voltage: European standard plugs and U.S. standard plugs

• According to the pinpoints: Two-prong and three-prong plugs

• According to the shape of the plug: There are many kinds, depending on different countries

The electrical parameters of the plug

This refers to the ability of the pin to withstand the maximum rated current and voltage such as European standard: 250V / 2.5A, 250V / 10A

The plug’s logo

• European standard plugs.

Certification mark: plugs generally have Germany VDE, France NF, the Netherlands KEMA, Denmark DMKO, Switzerland SEMKO, Austria OVE, Finland FI, Belgium CEBEC, and China CCC, and other country’s certification

• American standard plugs.

Certification marks: the United States UL, Canada CSA, Japan, Taiwan, and other certifications

About Power Cord

• According to the voltage points: European standard wire and U.S. common wire
• According to the material points: External insulation material: PVC wire, silicone wire, rubber wire, Teflon wire, preparation of silicone rubber wire
• According to the conductor material points: copper core wire and aluminum core wire, etc., the most commonly used is PVC copper core wire.

The specifications of the wire

EU power cord models are divided into ten parts.

1. Model: H03VVH2-F3G0.75

2. Byte: 12345678910111213

Represents the following.

• (The first byte) type: H for HARMONIZED (coordinating agency), A for OTHER STD (other agencies)
• (2nd-3rd byte) rated voltage value: 03=300/300V; 05=300/500V; 07=450/750V.
• (4th byte) basic insulation material: V=PVC; R=RUBBER (rubber); S=SI RUBBER (silicone rubber) N=POLYCHLOROPPENE RUBBER (neoprene); L=GLASS FIBER (glass fiber)
• (5th byte) additional insulation materials: the same as above, one more T = TEXTILE (woven fabric)
• (6th byte) unique parts: indicated by D3 can be omitted
• (7th byte) structure; H=FLAT SEPARATE CABLE, H2=FLAT NON-SEPARATE CABLE
• (byte 8) wire structure; F=FLOODY WIRE FINE CABLE, H=FLOODY WIRE VERY FINE CABLE
• (Byte 9) Number of wire cores
• (10th byte) grounding type: G = with grounding; X = without grounding
• (11-13 bytes) cross-sectional area: 0.75 = 0.75mm2

Plug Specifications

• CNA plugs
• UL rated plugs
• VDE plugs
• South Africa plugs
• Australia SAA plugs
• Israel SII plugs
• British BS plugs
• Switzerland SEV plugs
• Italy IMQ plugs

Safety regulations for the plug requirements.

• Plug type whose current value should not be less than the maximum current value of the apparatus
• UL regulations: can not appear as current and voltage, and UL LOGO can appear as file number or company transaction logo.
• CSA regulations can not appear as current and voltage but as CSA LOGO file number or company transaction logo.
• Products sold to Europe must be printed on the plug with the certification mark recognized by the region to which they are sold.

China power cord & plug Voltage: 220V / 50Hz.

China power cord numbering method:

Insulated wire can be divided into single-stranded wire and multi-stranded wire according to the number of strands of each wire. Usually, more than 6 square millimeters of insulated wire are multi-stranded wire, 6 square millimeters and below the insulated wire can be single-stranded wire, can also be multi-stranded wire, we also have 6 square millimeters and below the single-stranded wire called hard wire and a multi-stranded wire called soft wire.

• V is PVC polyvinyl chloride, that is (PVC plastic)
• L is the code for aluminum wire
• R is the meaning of (soft). Therefore, to achieve quiet is to increase the number of conductors.

• Wire commonly used insulation materials are PVC and polyethylene PE two, PVC with “V” said, polyethylene with “Y” said
• According to the number of mutually insulated wires fixed together, an insulated wire can be divided into single-core and multi-core wires. Multi-core wire can also be set in a single-core wire insulation sheath. The same sheath of multi-core wire can be up to 24 cores, parallel multi-core wire with “B,” stranded multi-core wire with “S ” said.

Model name

• BV: copper core polyvinyl chloride insulated wire

• BLV: Aluminum core PVC insulated wire

• BVV: Copper core PVC insulated PVC sheathed wire

• BLVV: Aluminum core PVC insulated PVC sheathed wire

• BVR: Copper core PVC insulated flexible wire

• RV: Copper core PVC insulated flexible installation wire

• RVB: Copper core PVC insulated flat connecting wire flexible wire

• BVS: Copper core PVC insulated stranded flexible wire

• RVV: Copper core PVC insulated PVC sheathed flexible wire

• BYR: Polyethylene-insulated flexible wire

• BYVR: Polyethylene insulated polyvinyl chloride sheathed flexible wire

• RY: Polyethylene-insulated flexible wire

• RYV: Polyethylene insulated polyvinyl chloride sheathed flexible wire

Europe Power Cord

European multi-country certification:

• Israel SII
• UK BS
• Australia SAA
• Germany VDE/GS
• France NF
• Netherlands KEMA
• Denmark DMKO
• Switzerland SEMKO
• Austria OVE
• Finland FI
• Belgium CEBEC
• European wire

1. H03VVH2-F: H is the European standard mark, 03 is the voltage resistance value, VV is the core Outside being pressure resistance, H2 is flat wire (no H2 for round wire), F is bendable wire

2. H03RR-F: H for the European standard mark, 03 for the pressure resistance value, the first R for the Core artificial rubber, the second R for the outer synthetic rubber, and F for the bendable wire.

3. H05RN-F:

H is the European standard mark.

N is the natural rubber.

F is the bendable wire.

4. H07RT-F: 

H is the European standard mark, T is the outer cotton yarn, F is the bendable line

• H03VVH2-F 2X0.5-0.75
• H05VVH2-F 2X0.75-1.0
• H03VV-F 2X0.5-0.75
• H05VV-F 2X0.75-1.0
• H03VV-F 3G0.5-0.75
• H05VV-F 3G0.75-1.5
• H03RT-F 3G0.75-1.5
• H05RR-F 3G0.75-1.5
• H05RN-F 3G0.75-1.5
• H07RN-F 3G1.0-1.5

Germany power cord & plug Voltage: 230V / 50Hz.

UK power cord & plug Voltage: 240V / 50Hz.

Italy power cord & plug Voltage: 230V / 50Hz.

Switzerland power cord & plug Voltage: 230V / 50Hz.

South Africa power cord & plug Voltage: 220-250V / 50Hz.

Australia power cord & plug Voltage: 240V / 50Hz.

Argentina power cord & plug Voltage: 220V / 50Hz.

Korea cord & plug Voltage: 220V / 50Hz.

The meaning of the label on the American-style power cord

• SPT-1 (W): S for UL specification line, P for parallel extraction, T for PVC covered, 1 for load level (three levels, including SPT-3 without outdoor type), W for outdoor line
• HPN: H for high-temperature resistance, P for parallel extraction, N for insulation rubber
• SVT: S for the UL specification line, V for general wire, T for PVC covered
• SJTOO: J for (Jacet) covered, T for PVC covered, the first O for the core oil resistant, the second O for covered oil resistantVW-1: for vertical combustion test, FT-1/2 for horizontal combustion test

American-style power cord letter description

1. SPT=Service Parallel Thermoplastic
2. HPN=Heater Parallel Neoprene
3. S=Service (SO, SOW, ST, STW) O-OIL, W-WET, T-Thermoplastic
4. SJ=Service Junior (SJO, SJOW, SJT, SJTW) O-OIL, W-Wet, T-Thermoplastic
5. SV=Service Vacuum Cleaner (SVT, SVO) O-OIL, T-Thermoplastic

Electronic wire

• Class 1 for internal use, Class 2 for external use
• Group A is not subject to mechanical abrasion, Group B is subject to mechanical abrasion

For example, CSA AWM I A 90 C 300 V FT1 indicates AWM electronic wire. Internal use, not subject to mechanical damage. Temperature resistance of 90 ℃, rated voltage: 300 V, combustion class FT-1.

• SPT series overall insulation (only insulation layer)
• SPT-1 18AWG/2C 1 series insulation is thinner, used for light electrical appliances
• SPT-2 18-16 AWG/2C 2 series insulation is a little thicker than the 1 series, used for light appliances, but the power is large
• SPT-3: 18-14 AWG 3 series insulation is the thickest, used for high-power appliance
• HPN 16AWG/2C (HPN is rubber wire)
• NISPT series is non-integral insulation (i.e. insulation layer + sheath)
• NISPT-1 20-18AWG/2C
• SJT: 18-14AWG/3C
• SJTW: 18-14AWG/3C
• SVT: 18-16AWG/3C

Specifications of American-style power cord

AWG stands for American Wire Gauge. Single wire conductors are based on diameter while the stranded wire is based on the cross-sectional area to determine the wire gauge. The larger the wire gauge, the smaller the cross-sectional area of the conductor.

USA &Canada power cord & plug Voltage: 120V / 60Hz.

Japan power cord & plug Voltage: 100V / 60Hz.

The maximum current that the wire conductor can withstand.

Power cord tension test.

1, the U.S. standard: in the power cord into the sample internal 25.4mm place flush cut, hanging 35LB weight (15.9KG) 1min, the power cord copper wire, rubber displacement of less than 2mm (can be tied UL knot)
2, Euro gauge: before applying force to tighten the power cord inside the virtual position, and then use 60N pulling force on the power cord 25 times (pulling force to the most unfavorable direction, shall not make the force, each time lasted 1 second), displacement of less than 2mm.

Power cord tension test

• The U.S. standard: In the power cord into the sample internal 25.4mm place flush cut, hanging 35 LB weight (15.9KG) 1min, the power cord copper wire, rubber displacement of less than 2mm (can be tied UL knot)

• Euro gauge: Before applying force to tighten the power cord inside the virtual position, and then use 60N pulling force on the power cord 25 times (pulling force to the most unfavorable direction, shall not make the force, each time lasting 1 second), displacement of less than 2mm.

Power cord testing requirements

1. Mechanical tests include: tension tests, swing test
2. Electrical tests include: temperature test, insulation strength test, overload test, aging test
3. The power cord flame retardant grade HB, V-2, V-1, and V-0 definition

HB to V-2, V-1, and V-0 step by step explanation

HB: UL94 and CSA C22.2 NO 0.17 standard is the lowest flame retardant grade. Yao seeks 3-13 mm thick samples, a burning rate of less than 40mm per minute, less than 3mm thick samples, a burning rate of less than 70mm per minute, or 100mm before the logo is extinguished.

V-2: Two 10-second burning tests on the sample after the flame is extinguished within 60 seconds, you can have burning material fall.

V-1: The flame is extinguished within 60 seconds after two 10-second burn tests on the sample. There can be no burning material falling.

V-0: After two 10-second combustion tests on the sample, the flame is extinguished within 30 seconds, and no burning material can fall.

FT1 Vertical Test: Flame in five to 15 seconds after the burning. Continued burning shall not exceed 60 seconds. There shall be no flame drops, and the flame indicator paper burning area shall not exceed 25%.

VW-1, FT1 Vertical Test: Flame resistance level is the same.

FT2 Horizontal Test: The continuous length shall not exceed 100mm.

FT4 Vertical flame test: Cable in cable tray, FT4 main combustion smoke generated when assessing the results. The extension of the flame length may not exceed 1.5mm

Burning level (FT1, FT2, or FT4): If the wire meets FT4 or VW-1 can not be marked FT1 or FT2 if it meets FT1 can not be marked FT2)

VW-1, FT1, and FT2 combustion grades are the lowest, and FT4 combustion grade is the highest.

FT6: Horizontal combustion and smoke test.

The exposed length of the UL power cord.

1. Handheld apparatus detachable or non-detachable power cord length should not be less than 5FT (152mm)
2. Tends to be most likely used on top of the cabinet apparatus whose additional flexible line length should not be less than 61mm
3. UL requires that the minimum wire diameter should not be less than 18 AWG

Wire Color Code.

To facilitate the wiring and identification of Live, Neutral, and Bonding during installation, the color of the insulation layer should meet the requirements. For example, in the case of the three-wire type, black for Live, white or light gray for Neutral, and green or yellow for Ground. If the product is sold to Europe, the color can be changed to brown for Live, light blue for Neutral, and green and yellow for Ground. Parallel lines SPT-2, HPN… … etc., must be ridged on the firewire with wire or printed with ink.

Power cord testing.

• The sampling method: by the GB2828 national standard sampling, inspectors take a certain percentage of the total number of samples to be tested
• The AQL acceptance criteria: fatal, serious, general
• The test content: Appearance, color, and certification mark

• Color testing basis: customer order    requirements
• Certification mark: safety certification CDF requirements and drawings on the description of whether the product is reported to the manufacturer, to confirm the consistency of specifications and models

• Visual: Batch front, stains, scratches, and the look at the outer plastic skin of the wire is bright, fine texture. When lit with a lighter there should be no open flame, substandard products using recycled plastic have a dull color, and loose texture, and can ignite an open flame.
• Size: plug, wire, and wire end size
• Testing basis: engineering drawings or relevant documents and information
• Testing content: plug pin size, size, shape, wire size, hardness, wire specifications and length, stripping length size, stripping method, half stripping or full stripping, dipping tin, connecting terminals, etc.
• Power cord high-voltage test: U.S. and European standards such as UL: 1000V / 1 min VDE: level 1: 1250V / 1min, level 2: 2500V / 2S
• Power cord tension test: Divided into two kinds: U.S. and European standards
• Test assembly: Installed on the product to confirm the assembly size is qualified.

Selection of internal wires and power cables.

Only when the length of the appliance cord does not exceed 2M can this cord be used. The length refers to the distance between the soft wire or soft wire protection device and the appliance to enter the plug. The power cord length should not be less than 80.

The JOYMI company power cord standard drawing reference.

At Zhongshan Jimi Electrical Appliance Co., Ltd., we prioritize aligning with these safety standards, ensuring our products are not just compliant but also reliable and safe for global markets.