Creepage Distance Caliper: A Comprehensive Analysis of Principles, Usage and Applications

The creepage distance caliper is a tool used to measure the creepage distance in electrical equipment.

What are the creepage distance and clearance?
The creepage distance refers to the shortest distance along the surface of the insulating material between two conductive components or between a conductive component and the protective interface of the equipment.

The electrical clearance refers to the shortest distance in the air between two conductive components. The design of this distance must ensure that the air gap will not be broken down when the equipment is subjected to transient overvoltage or peak voltage generated internally, thus protecting the safety of the equipment.

Creepage Distance Caliper

The creepage distance caliper is usually made in accordance with relevant electrical safety standards (such as IEC 60664-1, IEC60335-1, IEC60601-1, etc.), and it has scale or contour markings of different shapes and sizes. By comparing the test card with the layout of the conductive components on the insulating parts of the electrical equipment, it is possible to intuitively and conveniently determine whether the creepage distance meets the standard requirements.
The creepage distance calipers are divided into straight calipers and L-shaped calipers. The straight card is a straight-line-shaped caliper, mainly used to measure the straight-line distance between two conductive components or between a conductive component and the protective interface of the equipment. It is suitable for scenarios that require straight-line measurement. The curved card (L-sharped) is a curved-shaped caliper, suitable for scenarios where the shortest path along the surface of the insulating material needs to be measured. It can better simulate the curved path in actual use and ensure the accuracy of the measurement.

During the use process, if the clearance is smaller than the selected gauge, do not insert it forcefully. Otherwise, it will cause the caliper to bend and wear. A smaller caliper should be selected for inspection. In addition, the creepage distance caliper will been calibrated before leaving the factory, and wear should be avoided during use to prevent affecting the dimensional accuracy.

Why measure the creepage distance and clearance?

After the lamp is powered on, a leakage current path, that is, a creepage path, will be formed on the surface of the insulating material. If these leakage current paths form a conductive path, surface flashover or breakdown will occur. This is an electrical failure caused by insufficient creepage distance. In mild cases, it will damage the lamp, and in severe cases, it will cause personal injury or death. Using the creepage distance test card can help engineers and quality inspectors quickly and accurately determine whether the creepage distance meets the standard requirements, avoid problems such as discharge and breakdown along the insulating surface in a high-voltage environment due to insufficient creepage distance, thus ensuring the safe and reliable operation of electrical equipment, preventing electrical accidents, and ensuring the personal safety of users and the normal use of the equipment.

Application Scope of the Creepage Distance Caliper

The creepage distance caliper is widely used in the electrical equipment manufacturing industry, such as in the production process of household appliances (refrigerators, air conditioners, etc.), industrial control equipment, power transformers, switchgear and other electrical products. It is used to verify the rationality of the design in the product design, research and development stage, for quality control sampling inspection on the production line, and to determine whether the product complies with safety specifications in the product certification and safety inspection links.

The creepage distance caliper is available in sizes such as 8, 10, 20, and 30. Users can choose the appropriate model according to their needs. At the same time, we can also customize it according to the requirements of customers. The following are our regular sizes.