Safe Distance

        Safe Distance Includes electrical clearance (space distance), creepage distance (distance along the surface) and insulation penetration distance.

        1, Electrical clearance: the shortest distance between two adjacent conductors or one conductor along the surface of adjacent motor housing.

        Determination of electrical clearance: The distance is determined based on the measured operating voltage and insulation level. But usually: one side      communication part: L-N fuse is larger than 2.5mm, L.N,PE(earth) is more than 2.5mm, after the fuse device is not required, but as far as possible to maintain a    certain distance to avoid short circuit damage to the power supply.

        One side AC to DC part of more than 2.0mm A DC side of earth over 2.5mm(one side float grounding to the earth)

        A side part of the two side part is larger than 4.mm, the cross components connected between the one or two side of the electrical gap clearance is greater than or equal to 0.5mm can be part of the two sides. The two sides of the earth can be more than 1.mm.

        Note: to decide whether to meet the requirements, the internal parts should be sincere to the 10N force, 30N force to the shell, in order to reduce the distance, to confirm the worst case, the space distance is still in accordance with the provisions.

        2, Creepage distance: the shortest distance between two adjacent conductors or one conductor and the surface of adjacent motor shell along the insulated surface.

        Determination of creepage distance: (1), a side AC part: fuse L before-N>2.5mm, L.N>2.5mm fuse after the earth, cannot do, but try to keep a certain distance to avoid short circuit damage to the power supply. (2), a side AC to DC part of more than 2.mm. (3), a DC ground more than 4.mm as one side of the earth. (4), a side of the two sides is larger than 6.4mm, such as Y, capacitors and other components and parts. Footing spacing is less than or equal to 6.4mm to slot. (5), two times more than 0.5mm can be between the side part. (6), two times of more than 2mm above the earth side. (7), two class 8mm or above transformer.

        3, Insulation penetration distance:

        The following requirements shall be met according to the working voltage and the insulation application:

        —No voltage requirements for the operating voltage not exceeding 50V(71V AC peak value or DC value);

        —Additional insulation shall be minimum thickness of 0.4mm;

        When the insulation is strengthened without any mechanical stress that may cause deformation or deterioration of the insulation at normal temperatures, the minimum thickness of the strengthened insulation shall be 0.4mm. Provided that the insulation is provided in the protective enclosure of the equipment, but by bumping or abrasions in the maintenance and operating personnel will not belong to any one of the following situations:

        For additional insulation, use at least two layers of material, each of which can be tested by testing the electrical strength of the additional insulation; or an additional insulation consisting of three layers of material in which any combination of two layers of material can be tested by an electrical resistivity test of additional insulation; or for strengthening insulation, use at least two layers of material, each of which can be tested by strengthening the dielectric strength of insulation; or a reinforced insulation consisting of three layers of insulating material in which any combination of two layers of material can be tested by strengthening the dielectric strength of the insulation.

        The wiring process, pay attention to: such as capacitors and other flat surface components, must be flat without dispensing. If the two conductors in the 10N force can shorten the distance, less than the distance, less than the safety gauge distance requirements, dispensing parts can be fixed to ensure that the electrical clearance. In case of PVC film inside the enclosure, attention should be paid to safety distance (attention to processing). Parts dispensing fixed, pay attention to the PCB board cannot have foreign bodies such as silk. Insulation failures should not be caused when machining parts.

        Requirements for flameproof materials:

        Heat shrinkable casing V-1 or VTM-2 or more; PVC casing V-1 or VTM-2 or more

        Teflon sleeve V-1 or VTM-2; plastic material such as silicon film, insulating tape V-1 or VTM-2

About the insulation level:

        1)Work insulation: the insulation needed for the normal operation of the equipment

        2)Basic insulation: insulation to provide basic protection against electric shocks.

        3)Additional insulation: separate insulation applied in addition to basic insulation to protect the basic insulation against electrical shock when it fails.

        4)Double insulation: insulation consisting of basic insulation plus additional insulation

        5)Strength insulation: a single insulation structure that provides protection against electric shock equal to double insulation under the conditions set__ forth in this standard.