You Do Need power plug adapter while traveling from Zambia to South Africa.

Here is Why You Need An Adapter

The outlet and plug type used in South Africa are C, M and N and in Zambia are C, D and G. This is how they look like.

Zambia

In Zambia, outlets of type C, D and G are in use.

Type C

Type D

Type G

South Africa

In South Africa, outlets of type C, M and N are in use.

Type C

Type M

Type N