The City of Tshwane on Wednesday said preliminary reports showed that the Kwagga substation exploded as electricity was being restored in the early hours of Tuesday following load shedding.
There are fears that the impact of the rolling blackouts could become more severe, with some substations blowing up due to load shedding.
Large parts of Tshwane were left in the dark after the substation went up in flames.
Over the weekend, another substation exploded in Bryanston, leaving consumers there without power outside of their allocated time frame.
The city’s acting Mayor Abel Tau said: “Due to the outages, we understand that cellphone powers were also affected because they use electricity. A lot of other infrastructures that rely on electricity would have affected our communication lines, we are grateful that we are able to restore functionality to a 100%.”