### Safety Distance Requirements Between PCBA Board and Shell
The safety distance between the PCBA board and the enclosure encompasses electrical clearance, creepage distance, and insulation penetration distance.
1. **Requirements for Electrical Clearance Between PCBA Board and Housing:**
Electrical clearance is defined as the minimum distance measured through the air between two adjacent conductors or between a conductor and the surface of an adjacent motor casing. This distance is determined based on the measured working voltage and insulation level, typically as follows:
1) For the primary AC part: L-N ≥ 2.5mm before the fuse; L.N PE (earth) ≥ 2.5mm. No specific requirement is enforced after the fuse, but maintaining a safe distance is advisable to prevent short-circuit damage to the power supply.
2) The AC to DC portion of the primary side should be ≥ 2.0mm.
3) For the primary side DC ground to ground, the requirement is ≥ 2.5mm (between floating ground and ground).
4) The distance from the primary-side component to the secondary-side component must be ≥ 4.0mm, bridging the components between these two sides.
5) The electric gap on the secondary side must be ≥ 0.5mm.
6) A distance of ≥ 1.0mm from the secondary side ground to the earth is sufficient.
Note: Prior to assessing compliance with these requirements, apply a force of 10N to the internal components and 30N to the outer shell to minimize distance, ensuring that the separation still meets specifications under worst-case scenarios.
2. Creepage distance requirements between the PCBA board and the shell:
Creepage distance is defined as the shortest distance measured along the insulating surface between two adjacent conductors or between a conductor and the surface of the adjacent motor casing.
Creepage distances can be determined based on working voltage and insulation level; typically, they are as follows:
1) For the primary side AC part: L-N ≥ 2.5mm before the fuse, L.N to earth ≥ 2.5mm; after the fuse, no specific requirement exists, but maintaining a safe distance is recommended to prevent short-circuit damage to the power supply.
2) The distance from AC to DC on the primary side should be ≥ 2.0mm.
3) Primary side DC ground to ground should be ≥ 4.0mm, such as primary ground to ground.
4) The distance from the primary side to the secondary side must be ≥ 6.4mm; components like optocouplers and Y capacitors with foot spacing of ≤ 6.4mm should be slotted.
5) The distance between secondary side components should be ≥ 0.5mm.
6) The distance from secondary side ground to earth must be ≥ 2.0mm.
7) The distance between the two stages of the transformer should be ≥ 8.0mm.
3. Requirements for insulation penetration distance between the circuit board and the shell:
Based on working voltage and insulation application, the following standards must be adhered to:
1) If the working voltage does not exceed 50V (71V AC peak or DC), there is no thickness requirement.
2) The minimum thickness for additional insulation should be 0.4mm.
3) When reinforced insulation is not subjected to mechanical stress that could deform or degrade the insulating material under normal temperatures, the minimum thickness should also be 0.4mm.
If the provided insulation is used within a protective enclosure and will not be subject to impact or abrasion during maintenance, the following conditions apply, exempting thin-layer insulation materials regardless of their thickness:
1) For additional insulation, utilize at least two layers of materials, each capable of passing the electrical strength test for additional insulation.
2) Additional insulation can consist of three layers of materials, where any combination of two can pass the electrical strength test for additional insulation.
3) For reinforced insulation, employ at least two layers of materials, each passing the electrical strength test for reinforced insulation.
4) Reinforced insulation may consist of three layers of insulating materials, with any combination of two layers passing the electrical strength test for reinforced insulation.
The safety distance between the PCBA board and the enclosure encompasses electrical clearance, creepage distance, and insulation penetration distance.
1. **Requirements for Electrical Clearance Between PCBA Board and Housing:**
Electrical clearance is defined as the minimum distance measured through the air between two adjacent conductors or between a conductor and the surface of an adjacent motor casing. This distance is determined based on the measured working voltage and insulation level, typically as follows:
1) For the primary AC part: L-N ≥ 2.5mm before the fuse; L.N PE (earth) ≥ 2.5mm. No specific requirement is enforced after the fuse, but maintaining a safe distance is advisable to prevent short-circuit damage to the power supply.
2) The AC to DC portion of the primary side should be ≥ 2.0mm.
3) For the primary side DC ground to ground, the requirement is ≥ 2.5mm (between floating ground and ground).
4) The distance from the primary-side component to the secondary-side component must be ≥ 4.0mm, bridging the components between these two sides.
5) The electric gap on the secondary side must be ≥ 0.5mm.
6) A distance of ≥ 1.0mm from the secondary side ground to the earth is sufficient.
Note: Prior to assessing compliance with these requirements, apply a force of 10N to the internal components and 30N to the outer shell to minimize distance, ensuring that the separation still meets specifications under worst-case scenarios.
2. Creepage distance requirements between the PCBA board and the shell:
Creepage distance is defined as the shortest distance measured along the insulating surface between two adjacent conductors or between a conductor and the surface of the adjacent motor casing.
Creepage distances can be determined based on working voltage and insulation level; typically, they are as follows:
1) For the primary side AC part: L-N ≥ 2.5mm before the fuse, L.N to earth ≥ 2.5mm; after the fuse, no specific requirement exists, but maintaining a safe distance is recommended to prevent short-circuit damage to the power supply.
2) The distance from AC to DC on the primary side should be ≥ 2.0mm.
3) Primary side DC ground to ground should be ≥ 4.0mm, such as primary ground to ground.
4) The distance from the primary side to the secondary side must be ≥ 6.4mm; components like optocouplers and Y capacitors with foot spacing of ≤ 6.4mm should be slotted.
5) The distance between secondary side components should be ≥ 0.5mm.
6) The distance from secondary side ground to earth must be ≥ 2.0mm.
7) The distance between the two stages of the transformer should be ≥ 8.0mm.
3. Requirements for insulation penetration distance between the circuit board and the shell:
Based on working voltage and insulation application, the following standards must be adhered to:
1) If the working voltage does not exceed 50V (71V AC peak or DC), there is no thickness requirement.
2) The minimum thickness for additional insulation should be 0.4mm.
3) When reinforced insulation is not subjected to mechanical stress that could deform or degrade the insulating material under normal temperatures, the minimum thickness should also be 0.4mm.
If the provided insulation is used within a protective enclosure and will not be subject to impact or abrasion during maintenance, the following conditions apply, exempting thin-layer insulation materials regardless of their thickness:
1) For additional insulation, utilize at least two layers of materials, each capable of passing the electrical strength test for additional insulation.
2) Additional insulation can consist of three layers of materials, where any combination of two can pass the electrical strength test for additional insulation.
3) For reinforced insulation, employ at least two layers of materials, each passing the electrical strength test for reinforced insulation.
4) Reinforced insulation may consist of three layers of insulating materials, with any combination of two layers passing the electrical strength test for reinforced insulation.
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