Compliance Design for Electrical Product

This topic describes the hardware design issues in product certification.

Background information

This topic is a collection of common hardware design issues in the certification of some products. Note that this documentation is for reference only. The detailed information is subject to the certification authorities.

Things to note

This topic describes the hardware design issues of some reference products.

Representations

In this topic, the explanation of some representations are as follows:

Item	Explanation
L	Live wire
N	Neutral wire
L&N	Live wire and neutral wire are connected

List of key components

For the production compliance part and EMC part, the customer needs to provide a list of key components with relevant certifications.

Note: For special key components, it is best for customers to provide multiple alternative manufacturers.

Capacitors discharge in device

When the device is powered off, it is required to check whether L and N are at contact risk.

Reference product: a 10A wall switch with a USB port

Executive standard	Condition	Standard
GB4943.1-2011	There are capacitors with a capacity of more than 0.1 µF on L and N.	The discharge time is less than one second.

Note: The discharge time is 37% of the time it takes for the voltage to drop to the initial value.

Reference product: a 15A American standard socket converter

Executive standard	Condition	Standard
UL 60730-1	There are capacitors with a capacity of more than 0.1 µF on L and N.	Peak voltage does not exceed 34V after one second.

Fuse

Reference product: a 10A wall switch with a USB port

Executive standard	Fuse identifier
GB4943.1-2011	The fuse parameters need to be marked around the fuse of the PCB.

Reference product: Australian standard 10A socket converter

Executive standard	Fuse identifier
AS / NZS 3105: 2014 + A1: 2017 AS / NZS 3100: 2017 + A1: 2017	When the fuse is blown, no spark can be generated.

Temperature rise

Reference product: a 10A wall switch with a USB port

Executive standard	Test current (The rated current is 10A)	Test current (The rated current is 16A)	Test time	Terminal temperature rise
GB/T2099.1	16A	22A	1 hour	45k

Note: The test items include the temperature rise between L and N, L and ground wire, and N and ground wire. The temperature rise needs to be within the working temperature range in the datasheet.

Reference product: appliance switch

Executive standard	Test current (The rated current is 10A)	Test time	Terminal temperature rise
GB/T15092.1	10.6A	After the test temperature is stable, run for another hour.	45k

Note: The temperature rise needs to be within the working temperature range in the datasheet.

Reference product: a 15A American standard socket converter

Executive standard	Test current (The rated current is 15A)	Test time	Terminal temperature rise
UL 60730-1	15A	After the test temperature is stable, run for another hour.	25k

Executive standard	Test current (The rated current is 15A)	Test time	Terminal temperature rise
UL 498A	15A	After the test temperature is stable, run for another hour.	30k

Note: The temperature rise needs to be within the working temperature range in the datasheet.

Overload test

Executive standard	Test current (The rated current is 15A)	Test time	Limit temperature
UL 60730-1	27A	1 hour	125°C

Electrical clearance

Reference product: a 10A wall switch with a USB port

Executive standard	Clearance between different live parts	Clearance between the live part and the accessible insulating surface	Clearance between the live part and the ground wire	Clearance between the fuse soldering spots	Clearance between the electrical device and the extra-low voltage device	Clearance between the ground wire and the extra-low voltage device
GB/T2099.1 GB4943.1-2011	3 mm	3 mm	3 mm	1.5 mm	4.0 mm	1.5 mm

Note: The altitude is below 2000m.

Reference product: a 16A wall switch

Executive standard	Clearance between different live parts	Clearance between the live part and the ground wire	Clearance between the live part and the accessible insulating surface
GB/T2099.3	3 mm	3 mm	3 mm

Reference product: appliance switch

Executive standard	Pollution level	Clearance between different live parts	Clearance between the live part and the ground wire	Clearance between the live part and the accessible insulating surface
GB/T15092.1	2	1.5 mm	1.5 mm	1.5 mm

Reference product: a 15A American standard socket converter

Executive standard	Clearance between different live parts	Clearance between the live part and the ground wire	Clearance between the fuse soldering spots	Clearance between the relay contact and the cord
UL 60730-1	0.5 mm	0.5 mm	0.5 mm	0.5 mm

Creepage distance

Reference product: a 10A wall switch with a USB port

Executive standard	Clearance between different live parts	Clearance between the live part and the accessible insulating surface	Clearance between the live part and the ground wire	Clearance between the fuse soldering spots	Clearance between isolated circuits
GB/T2099.1	3 mm	3 mm	3 mm	2.5 mm	5.0 mm

Reference product: a 16A wall switch

Executive standard	Clearance between different live parts	Clearance between the live part and the ground wire	Clearance between the live part and the accessible insulating surface
GB/T2099.3	3 mm	3 mm	3 mm

Reference product: appliance switch

Executive standard	Pollution level	Clearance between different live parts	Clearance between the live part and the ground wire	Clearance between the live part and the accessible insulating surface
GB/T15092.1	2	2.5 mm	2.5 mm	2.5 mm

Reference product: a 15A American standard socket converter

Executive standard	Clearance between different live parts	Clearance between the live part and the ground wire	Clearance between the fuse soldering spots	Clearance between the relay contact and the cord
UL 60730-1	1.5 mm	1.5 mm	0.5 mm	0.5 mm

Insulation resistance

Reference product: a 10A wall switch with a USB port

Executive standard	Test voltage	Duration	Insulation resistance
GB/T2099.1	DC 500V	1 min	≥5 MΩ

Reference product: a 16A wall switch

Executive standard	Test voltage	Duration	Insulation resistance (between L&N and the ground wire)	Insulation resistance (between L&N and the shell)
GB/T2099.3	DC 500V	1 min	≥5 MΩ	≥5 MΩ

Reference product: appliance switch

Executive standard	Test voltage	Duration	Insulation resistance (between L&N and the ground wire)	Insulation resistance (between L&N and the shell)
GB/T15092.1	DC 500V	1 min	≥2 MΩ	≥2 MΩ

Reference product: a 15A American standard socket converter

Executive standard	Test voltage	Duration	Insulation resistance (between L&N and the ground wire)	Insulation resistance (between L&N and the shell)
UL 60730-1	DC 500V	1 min	≥2 MΩ	≥7 MΩ

Executive standard	Test voltage	Duration	Insulation resistance (between L&N and the ground wire)	Insulation resistance (between L&N and the shell)
UL 498A	DC 500V	1 min	≥100 MΩ	≥100 MΩ

Electric strength

During the test, no flashover or breakdown should occur.

Reference product: a 10A wall switch with a USB port

Executive standard	Test voltage	Duration	Frequency
GB/T2099.1	AC 2000V	1 min	50 Hz

Executive standard	Between L and N (fuse disconnected)	L&N and accessible output	L&N and accessible shell
GB4943.1-2011	AC 1500V	AC 3000V	AC 3000V

Reference product: a 16A wall switch

Executive standard	Duration	Frequency	Test voltage (between L&N and the ground wire)	Test voltage (between L&N and the shell)
GB/T2099.3	1 min	50 Hz	1200V	2000V

Reference product: appliance switch

Executive standard	Duration	Frequency	Test voltage (between L&N and the ground wire)	Test voltage (between L&N and the shell)	Test voltage (between relay contacts)
GB/T15092.1	10s	50 Hz	1500V	1500V	500V

Reference product: a 15A American standard socket converter

Executive standard	Duration	Frequency	Test voltage (between L&N and the ground wire)	Test voltage (between L&N and the shell)
UL 60730-1	1 min	60 Hz	1200V+U	2400V+ (2*U)

Note: U is the working voltage.

Surge current test

Reference product: a 15A American standard socket converter

Executive standard	Open circuit	Short circuit	Differential mode	Common mode
UL 60730-1	1.2/50µs	8/20µs	1 kV	2 kV

Group pulse test

Reference product: a 15A American standard socket converter

Executive standard	Frequency	Pulse duration Td	Rise time Tr	Voltage
UL 60730-1	5 kHz	15 ms	300 ms	1 kV

Relay

Both the Australian socket converter and the German GS standard require L and N to be disconnected at the same time, which can be realized by a two-way on-off relay or two relays (two relays need to be on and off at the same time).

Rectification strategy for excessive temperature rise

First, you need to find out the point where the temperature rise exceeds the standard, and act accordingly.

The temperature rise of the connection terminal exceeds the standard

• Select a terminal made of a better metal material.
• The contact area between the connecting terminal and the power cord or plug should be as large as possible.

The temperature of the PCB main current circuit part exceeds the standard.

• Increase the copper area of the main current circuit.
• Increase the copper thickness of the PCB.
• Open the window to the main current circuit to increase the amount of tin.
• Increase the contact area of each soldering point of the main current circuit to ensure good current flow performance.

Relay temperature exceeds the standard.

• Replace the relay with a better-performance relay.
• Increase the connection area between the relay and the PCB board to ensure the contact area is as large as possible.

Rectification plan for overload temperature rise

• Add a current fuse to the main circuit to form overcurrent protection.
• Add a thermal fuse to the main circuit, and place the temperature probe close to the heating point with the greatest heat.