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China is now the largest countries in the world to manufacture and supplier of industrial sockets and industrial plug.


In China nationwide, most of the industrial plug and socket suppliers are in Zhejiang province. As a well known international trading hub, more and more foreign clients are visiting Zhejiang and buy these products.


To choose your favorite supplier can be difficult, because of two issues: first, the quality can be different, second, China has its own industrial standard for this product, which can be slightly different from the standard in the client’s country.


But if you know the following 5 things, you will save a lot of time and energy before visiting Chinese factories.


The standards:


For industrial socket and plug, there are more than 1 standards, such as IEC60309 (ceeform) standard which is made by the EU; the Chinese GB standard, the American UL standard.


IEC, GB and UL standard 


Based on these different standards, there are different specifications. The current specification is a typical example.


For IEC and Chinese GB standard, the industrial socket and plug have 16a, 32a, 63a and 125a.


For the American UL standard, there are 20a, 30a, 60a, 100a.


Despite the different numbers, they can be compatible. The 16a, 32a, 63a and 125a products from IEC and GB standard are compatible with 20a, 30a, 60a and 100a products respectively from the American UL standard.


The color and voltage:


For clients who are buying for the first time, you may be confused by the colors. However, unlike any other products, the colors of industrial socket and plug are seriously regulated.

colors of the industrial socket and plug


According to the international standard, the blue color refers to the product of 230v; the red color refers to the product of 400v, the white color refers to the product of below 50v (the super low voltage); the purple refers to the product of 20v; the black refers to the product used in entertainment industry.


The poles:


The industrial socket and plug have many poles configurations. The pole configuration decides number of pins of industrial plug and socket. At least you should know the 3 most sold types.


3P (2P+E): this is known as 3 poles or single phase;


4P (3P+E): this is 4 poles or 3 phase;


5P (3P+N+E): this is 5 poles or 3 phase;


Note that 4p and 5p are both 3 phase industrial socket or plug.


The earth position:


If you read the specifications of a product, you can find values like 4h, 6h or 12h. This is called the earth position.


The h means hour. If you look at a clock, 4h means just exactly 4:00 position where the pointer points.


In the industrial socket and plug field, a clock map is used to define the earth pin position.

the clock map


For example, according to the international standard, if the earth position is at 3h, these plugs and sockets can only be used for ships, cargo, wharf or container.


Waterproof ratings:


Chances are you may need the industrial socket and plug work in the extreme environment where the ordinary products are not competent.


What you need is waterproof socket and plug. The waterproof products are actually waterproof and dust resistance.


IP44 and IP67 are the main products of this kind.


The two numbers after “IP” refers to the degree of how the product is dust proof and waterproof. 

Contact Us

+86-577-62960887
No.1 Huashan Road, Wenzhou Bridge Industrial Zone, Baixiang, Yueqing 325603, China

Company Details

Zhejiang Xiyiyi Electrical Equipment Co., Ltd is a professional supplier of international standards waterproof industrial plug sockets, connectors, distribution boxes and protection relays, etc. Since its founding in 1991, our company continued to develop due to the reliability of our products and services.

Zhejiang Xiyiyi Electrical Equipment Co., Ltd