What is creepage voltage?
Creepage distance means the shortest distance along the surface of a solid insulating material between two conductive parts. This voltage is the working voltage, the rated insulation voltage or the rated voltage.
How can creepage distance be improved?
Thinking back to the mountaintop metaphor, one way to increase creepage is to make a valley between the peaks. You can cut grooves or troughs into the PCB substrate to increase creepage. You can also sometimes cut slots all the way through the insulator to increase the distance.
What causes creepage?
This can include an accumulation of conductive contaminants that can become conductive with moisture (i.e. dust). This also includes periodic overvoltage events on the mains voltage. These events can be caused by a number of normal situations including weather and switching induced overvoltages.
What does creepage mean?
Definition of creepage : gradual movement : creep.
How is creepage measured on a high voltage PCB?
What is Creepage on a PCB? Similar to clearance, creepage measures distance between conductors on for high voltage PCB. However, instead of measuring distance in air, it measures the shortest distance along the surface of the insulation material. Board material and environment also affect creepage requirements.
What’s the difference between creepage and clearance in insulation?
1 Clearance: In the “line of sight” distance or the shortest air path between two conductors. The shortest distance that… 2 Creepage: The shortest distance between two conductors along the insulating surface. 3 Creepage must be greater than or equal to clearance. More
When to use creepage and clearance in a circuit?
Remember to maintain clearance from the bounding surface and through-hole connection points, if present. Nodes within the same high voltage circuits at the same potential usually do not require increased clearance or creepage to each other, but do require clearance to low voltage circuits.
What should creepage distance be for switch mode power supply?
When designing a switch-mode power supply for use in information technology (IT) equipment, a typical rule of thumb is to allow an 8-mm creepage distance between primary and secondary circuits, and a 4-mm distance between primary and ground.