What is the importance of creepage distance?

What is the importance of creepage distance?

The isolation required between parts with different operating voltages, to prevent against unacceptable risk, is the primary reason for the importance of creepage and clearance distances.

What is creepage factor?

Creepage Factor (CF), is a global check of the overall density of creepage distance and is equal to l/A where: l is the total creepage distance of the insulator and A is the arcing distance of the insulator. For disc insulators the CF is determined for a string comprising at least 5 insulator units.

How do you measure creepage distance?

How to Determine Creepage Distance for Connectors

1. Creepage Distance/Air Gap: The Path of Least Resistance.
2. Check the Pins on the Connector Face.
3. Check the Backside of the Connector:
4. Check Female Contacts as well:
5. Check For Hidden Creepage Paths Inside the Connector.
6. Check for Hidden Creepage Paths Outside the Connector.

What is the difference between creepage and clearance?

Clearance is the shortest distance in air between two conductive parts. Creepage distance means the shortest distance along the surface of a solid insulating material between two conductive parts.

Can electricity flow through insulators?

In a conductor, electric current can flow freely, in an insulator it cannot. Metals such as copper typify conductors, while most non-metallic solids are said to be good insulators, having extremely high resistance to the flow of charge through them.

What is creepage distance in PCB?

Creepage: This is the distance between two conductors on the surface of the board, or along the surface of insulating material. Clearance: This is the line-of-sight distance between two conductors through the air.

What is creepage distance in surge arrester?

Creepage distance is the distance on the surface of the housing from high to low voltage end (see Fig. 4). This parameter is critical when an arrester is being applied in areas where there is salt, industrial or other contamination. Creepage distances typically range from 25 mm/kV to 35 mm/kV of applied voltage.

What is creepage in PCB?

Creepage is the shortest distance between conductor traces on a PCB along the surface of the insulation material while clearance is defined as the minimum distance through the air (line of sight) between two conductor traces. Clearance and creepage distances between two PCB conductors.

What IPC 2221?

IPC-2221 is a generic standard for circuit board design. It lays down the requirements for PCB design and different forms of component mounting/interconnection structures. Thus IPC-2221 becomes the basis on which the design principles and recommendations for boards are established.

What is the purpose of insulators in a circuit?

Electrical insulators are used to hold conductors in position, separating them from one another and from surrounding structures. They form a barrier between energized parts of an electric circuit and confine the flow of current to wires or other conducting paths as desired.

What is protected creepage distance of an insulator?

Protected creepage distance of an insulator means part of the creepage distance on the illuminated side of the insulator which would lie in shadow if light were projected on to the insulator at 90° (or 45°in special cases) to the longitudinal axis of the insulator.

What is the meaning of creepage or creep distance?

Creepage or creep distance is pretty simple. It relates to the surface shape of the insulator. Creep distance is sometimes referred to as leakage distance. It represents the shortest distance along the surface of the insulator between the conductive ends of the insulator.

How to determine the creepage distance of a circuit?

The basis for the determination of a Creepage Distance is the long term r.m.s. value of the voltage existing across it. This voltage is the working voltage, the rated insulation voltage or the rated voltage.

How do engineers increase the creep distance of an insulator?

Engineers add “sheds” to the insulator to maximize the creep distance. This helps in two ways. First, the geometry of a shed increases the surface distance on the insulator from end to end. This increases the creep distance.