Quick answer
Half the house losing power is typically a tripped sub-circuit, a failed neutral on the incoming supply, or a partially failed main switch. On a three-phase supply, losing one phase presents exactly this way. It matters because a partial supply fault does not just inconvenience you — unbalanced or missing phases damage motors, fridges and electronics while they try to run on it.
Common causes
- Tripped sub-circuit or sub-board breaker
- Failed neutral on the incoming supply
- Lost phase on a three-phase supply, from the municipality or at the point of supply
- Partially failed main switch with one pole not making contact
- Loose connection at the meter or supply point
- Municipal fault affecting one phase across the street
What you can do now
- 1Check the DB for breakers sitting in the partially tripped middle position
- 2Check for a sub-board elsewhere in the house or in an outbuilding
- 3Switch off large appliances on the dead section to protect them
- 4Ask neighbours whether they have partial supply too, which points at a municipal phase loss
- 5Do not run motors, fridges or aircon on the affected section until it is resolved
When to call a professional
Same day. Partial supply faults damage motors and appliances quickly, and a failed neutral in particular can put dangerous voltages on parts of the installation. A registered electrician will verify the supply at the point of entry, test each phase and the neutral, and establish whether the fault is inside the property or on the municipal side.
Typical cost in Johannesburg
Emergency callout R750
Indicative ranges only. We provide written, itemised quotes before any work.
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