As the core equipment for power supply in African rural households, the insulation resistance between the installation board and the outer shell of the lighting electrical ready board in African rural areas directly affects electrical safety and equipment service life. Combining international standards and the usage environment in African rural areas, it is specified that the insulation resistance value should not be less than 1 megaohm (M Ω), and should be increased to 2 megaohms or more in special environments.

This standard is mainly developed based on relevant international standards of IEC, and is also adapted to the actual needs of low-voltage lighting in rural Africa - the rated voltage of local lighting electrical ready boards is mostly 220V-400V, which belongs to low-voltage complete equipment. The insulation resistance between the installation board (carrying electrical components) and the box shell (grounding conductor) needs to meet the general requirements of low-voltage auxiliary circuits, that is, not less than 1 megaohm.

Considering the special environment of rural Africa, the insulation resistance requirements need to be flexibly adjusted: high humidity in tropical grasslands and rainforest areas can easily cause insulation materials to become damp and aged, and the insulation resistance needs to be increased to 2 megohms or above; In high-altitude rural areas (such as parts of the East African Plateau), low air pressure can reduce insulation performance. Although the standard value is still not less than 1 megaohm, stable performance needs to be ensured through air pressure simulation testing. In addition, countries such as South Africa have local mandatory regulations that must comply with SANS related standards to ensure equipment compliance.

During testing, a 500V megohmmeter should be used to operate in an environment of 10 ℃ -40 ℃ and relative humidity ≤ 75%. The stable value after 1 minute should be read as the final result. If the measured value is lower than the standard, it is necessary to investigate issues such as insulation material damage, moisture, dust pollution, etc., replace qualified insulation components in a timely manner, and retest. Compliant insulation resistance can effectively block leakage current, prevent electric shock accidents caused by electrified enclosures, adapt to the limited maintenance conditions of rural power facilities in Africa, and ensure the safe and stable use of electricity for rural lighting.