Quick answer
Voltage spikes when supply is restored are what damage fridges, TVs and routers — not the outage itself. The moment power returns, the network can swing well outside normal limits for a short period, and sensitive electronics take that hit. A whole-house surge arrester at the board plus a UPS for the most sensitive equipment deals with almost all of it.
Common causes
- Restoration voltage spike as supply returns after an outage
- Phase imbalance on return, particularly on a three-phase supply
- Brown-out conditions where voltage sags but does not disconnect, which is hard on motors
- Repeated hard restarts of compressors in fridges and air conditioners
- No surge protection fitted at the distribution board
- Sensitive electronics left plugged in with no point-of-use protection
What you can do now
- 1Unplug sensitive electronics during scheduled load shedding
- 2Switch off large appliances before the scheduled restoration time
- 3Wait a few minutes after power returns before switching things back on
- 4Fit point-of-use surge plugs for computers, TVs and routers
- 5Note which items keep failing — a pattern helps size the protection correctly
When to call a professional
Have a surge arrester fitted at the distribution board. It is modest money against the cumulative cost of replacing appliances every few months, and insurers become noticeably less accommodating about repeated surge claims on an installation with no protection. Combine it with a DB inspection, since the board has to be opened either way.
Typical cost in Johannesburg
Surge arrester R3,500–R6,500 · UPS R1,800+
Indicative ranges only. We provide written, itemised quotes before any work.
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