Introduction to protection grade of common dry-type transformer

2022-05-12 10:54:31

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IP (ingress protection) protection level system is drafted by IEC (International Electrical Communication). The electrical appliances shall be classified according to their dust-proof and moisture-proof characteristics. The foreign objects mentioned here, including tools and human fingers, shall not touch the live parts in the electrical appliance to avoid electric shock. IP protection level is composed of two numbers. The first number indicates the level of dust separation and prevention of foreign object intrusion of the lamp, and the second number indicates the tightness of the lamp against moisture and waterproof intrusion. The larger the number, the higher the protection level. Refers to the dust-proof and waterproof grade of the transformer, 2 refers to the dust-proof grade, and 0 refers to the waterproof grade. The meanings of each grade are shown in the following table:

1. IP dust-proof grade:

NO.	Protection Scope	explain
0	unprotected	No special protection from people or things outside
1	Prevent the intrusion of solid foreign objects with a diameter greater than 50mm	Prevent the human body (such as palm) from accidentally contacting the parts inside the electrical appliance, and prevent the intrusion of foreign objects with large size (diameter greater than 50mm)
2	Prevent the intrusion of solid foreign objects with a diameter greater than 12mm	Prevent people's fingers from contacting the parts inside the electrical appliance and prevent the intrusion of foreign objects with medium size (diameter greater than 12.5mm)
3	Prevent the intrusion of solid foreign objects larger than 2.5mm in diameter	Prevent tools, wires and similar small foreign objects with diameter or thickness greater than 2.5mm from invading and contacting the parts inside the electrical appliance
4	Prevent the intrusion of solid foreign objects larger than 1.0mm in diameter	Prevent tools, wires and similar small foreign objects with diameter or thickness greater than 1.0mm from invading and contacting the parts inside the electrical appliance
5	Prevent foreign objects and dust, and completely prevent foreign objects from invading	Although dust intrusion cannot be completely prevented, the amount of dust intrusion will not affect the normal operation of electrical appliances
6	Prevent foreign objects and dust	Completely prevent the invasion of foreign objects and dust

2. IP waterproof grade:

NO.	Protection range	explain
0	Unprotected	No special protection against water or moisture
1	Prevent water droplet intrusion	Vertically falling water droplets (such as condensate) will not cause damage to electrical appliances
2	When the inclination is 15 degrees, the intrusion of water droplets can still be prevented	When the appliance is tilted from vertical to 15 degrees, dripping water will not cause damage to the appliance
3	Prevent the intrusion of sprayed water	Protect against rain or damage caused by water sprayed in the direction with an included angle of less than 60 degrees from the vertical
4	Prevent splashing water from entering	Prevent the water splashed from all directions from invading the electrical appliance and causing damage
5	Prevent the intrusion of sprayed water	Prevent the water from flying in all directions from the nozzle from invading the electrical appliance and causing damage
6	Prevent big waves from invading	The electrical appliances installed on the deck can prevent damage caused by big waves
7	Prevent water intrusion during immersion	If the electric appliance is immersed in water for a certain time or the water pressure is below a certain standard, it can ensure that it will not be damaged due to immersion
8	Prevent water intrusion when sinking	The electric appliance sinks under the specified water pressure indefinitely, which can ensure that it will not be damaged by immersion

Dry type transformer shell is divided into indoor transformer shell and outdoor voltage transformer shell according to different application occasions. According to different structural materials, the shell of dry-type transformer is divided into three categories: aluminum alloy transformer shell, stainless steel transformer shell and steel plate spraying transformer shell. It is mainly used for safety protection of operating transformer site. Avoid operation accidents caused by foreign matters such as small animals entering the transformer. It can effectively protect personal safety and play a certain role in electromagnetic shielding. Today, let Evan, an electrical engineer of HENGFENGSHUAI ELECTRIC, summarize the protection grade of common dry-type transformers:

There are mainly IP00, IP20, IP23, IP55 (outdoor) and other forms. IP00 is transformer without enclosure (without protection). IP20 is a transformer with a shell, which can prevent the entry of solid foreign matters greater than 12mm. In addition to the IP20 shell function, the IP23 shell can also prevent the inflow of water droplets at an angle of 60 ° to the vertical direction. IP55 is mainly used outdoors to prevent water flow at all angles.

The protection grade of dry-type transformer shell is divided into: IP20, IP21, IP23, IP30, IP31, ip33, IP40, IP55 and other specifications.

IP level	IP protection range
IP20	It can prevent the entry of spherical foreign matters with a diameter greater than 12.5mm and provide a safety barrier for the live part
IP21	It has IP20 performance and can prevent vertical water droplets from entering
IP23	It has IP20 performance and can prevent water from entering within the range of 60 ° to the vertical line
IP30	It can prevent spherical foreign matters with a diameter greater than 2.5mm from entering
IP31	It has IP30 performance and can prevent vertical water droplets from entering
IP33	It has IP30 performance and can prevent water from entering within the range of 60 ° to the vertical line
IP40	It can prevent linear objects with a diameter greater than 1mm from entering and has dust-proof effect
IP55	It can prevent water sprayed from all angles from entering