GB14711 stipulates that the creepage distance and electrical clearance of low-voltage motors refer to: 1 ) Between the conductors passing through the surface of the insulating material and the space. 2 ) The distance between exposed live parts of different voltages or between different polarities. 3 ) The distance between exposed live parts (including magnet wires) and parts that are (or may be) grounded when the motor is operating. The creepage distance and electrical clearance vary according to the voltage value and should comply with the provisions of Table 1 . For motors with a rated voltage of 1000V and above, the electrical gaps between different exposed live parts or parts of different polarity in the junction box and between exposed live parts (including electromagnetic wires) and non-current-carrying metal or movable metal casings and The creepage distance should not be less than the requirements in Table 2 .
Table 1 Minimum electrical clearance and creepage distance under different voltages for live parts of motors below 1000V
| cabin seat no | Related parts | The highest voltage involved | Minimum spacing: mm | ||||||
| Between bare electrical components of different polarities | Between non-current-carrying metal and live parts | between removable metal housings and live parts | |||||||
| electrical clearance | Creepage distance | electrical clearance | Creepage distance | electrical clearance | Creepage distance | ||||
| H90 and below motors | Terminals | 31~375 | 6.3 | 6.3 | 3.2 | 6.3 | 3.2 | 6.3 | |
| 375~750 | 6.3 | 6.3 | 6.3 | 6.3 | 9.8 | 9.8 | |||
| Parts other than terminals, including plates and posts connected to terminals | 31~375 | 1.6 | 2.4 | 1.6 | 2.4 | 3.2 | 6.3 | ||
| 375~750 | 3.2 | 6.3 | 3.2 * | 6.3 * | 6.3 | 6.3 | |||
| H90 or above motor | Terminals | 31~375 | 6.3 | 6.3 | 3.2 | 6.3 | 6.3 | 6.3 | |
| 375~750 | 9.5 | 9.5 | 9.5 | 9.5 | 9.8 | 9.8 | |||
| Parts other than terminals, including plates and posts connected to terminals | 31~375 | 3.2 | 6.3 | 3.2 * | 6.3 * | 6.3 | 6.3 | ||
| 375~750 | 6.3 | 9.5 | 6.3 * | 9.5 * | 9.8 | 9.8 | |||
| * Magnet wire is considered an uninsulated live part. Where the voltage does not exceed 375 V, a minimum distance of 2.4 mm through air or surface is acceptable between the magnet wire, which is firmly supported and held in place on the coil, and the dead metal part. Where the voltage does not exceed 750 V, a spacing of 2.4 mm is acceptable when the coil has been suitably impregnated or encapsulated. | |||||||||
| The creepage distance between solid charged devices (such as diodes and thyristors in metal boxes) and the supporting metal surface can be half of the value specified in the table, but shall not be less than 1.6mm. | |||||||||
Table 2 Minimum clearances and creepage distances of live parts of motors above 1000V under different voltages
| Related parts | Rated voltage: V | Minimum spacing: mm | |||||
| Between bare electrical components of different polarities | Between non-current-carrying metal and live parts | between removable metal housings and live parts | |||||
| electrical clearance | Creepage distance | electrical clearance | Creepage distance | electrical clearance | Creepage distance | ||
| Terminals | 1000 | 11 | 16 | 11 | 16 | 11 | 16 |
| 1500 | 13 | twenty four | 13 | twenty four | 13 | twenty four | |
| 2000 | 17 | 30 | 17 | 30 | 17 | 30 | |
| 3000 | 26 | 45 | 26 | 45 | 26 | 45 | |
| 6000 | 50 | 90 | 50 | 90 | 50 | 90 | |
| 10000 | 80 | 160 | 80 | 160 | 80 | 160 | |
| Note 1: When the motor is energized, due to mechanical or electrical stress, the spacing reduction of rigid structural parts should not be greater than 10% of the normalized value. | |||||||
| Note 2: The electric clearance value in the table is based on the requirement that the altitude of the motor working site does not exceed 1000m. When the altitude exceeds 1000m, the electric clearance value in the table will increase by 3% for every 300m rise. | |||||||
| Note 3: For the neutral wire only, the incoming line voltage in the table is divided by √3 | |||||||
| Note 4: The clearance values in the table can be reduced by using insulating partitions, and the performance of this kind of protection can be verified by withstand voltage strength tests. | |||||||
Post time: Aug-30-2023