In Kenya, electricity from the grid is rarely a perfectly stable 240V. Fluctuations, sudden outages, and lightning strikes are common risks that can destroy sensitive modern electronics like solar inverters, LED TVs, and computers.
The challenge is not only dramatic lightning events. Repeated over-voltage, under-voltage, and poor earthing can shorten the life of equipment slowly, which is why protection strategy matters as much as the inverter brand itself.
Types of Surges
Surges generally come in two forms:
- Transient Surges: Brief bursts of high voltage (e.g., from a nearby lightning strike). These can fry circuits instantly.
- Over/Under Voltage: Sustained periods where voltage stays too high (e.g., 270V) or too low (e.g., 180V). This causes overheating and long-term damage to compressors and motors.
These two risks are related but not identical. A surge protector (SPD) and an automatic voltage protection device do different jobs. A professional system usually needs both, supported by good earthing and proper board integration.
The Three-Tier Protection Strategy
A professional installation goes beyond just a simple circuit breaker. Iselle uses a multi-tiered approach:
- AC Surge Protective Devices (SPD): These are installed in your main DB board. They "clamp" high-voltage transients and safely divert them to the earth before they reach your house.
- DC Surge Protection: This protects the solar input. Lightning doesn't have to strike your panels directly—a strike nearby can induce a massive current in the DC cables.
- AVS (Automatic Voltage Switchers): These are digital guards that disconnect the grid power entirely if the voltage goes outside a safe range (for example, below 190V or above 260V), only reconnecting once the grid stabilizes.
Where protection should be placed
Protection works best when devices are installed at the correct points in the system, not added as an afterthought. Depending on the project, this may include the main DB, sub-boards for essential circuits, PV combiner/isolator points, and sensitive downstream loads.
Placement matters because the goal is to intercept faults or abnormal voltage before they propagate to expensive equipment. One device in the wrong place is often less effective than a coordinated protection layout.
Earthing: The Foundation of Safety
No surge protector works without a high-quality Earth Loop. We test every property's earth resistance before installation. If the soil is dry or rocky, we install specialized earth rods to ensure electricity has a clear path to ground during a fault.
Earthing also affects fault-clearing behavior and the reliability of protective devices. A system can have premium SPDs installed and still perform poorly if the earth path is weak or the installation is not bonded correctly.
Common protection mistakes we see
- Installing SPDs but skipping earthing tests
- Using underspecified devices that do not match the installation environment
- No separation of essential and non-essential circuits in backup systems
- Relying on extension-strip surge protectors as the main protection strategy
- Ignoring repeated voltage instability because "the power came back"
What Iselle checks during protection work
- DB condition, space, and safe integration points for new protective devices
- Earthing / grounding condition and bonding continuity
- AC and DC isolation and protection layout for the installed scope
- Voltage behavior risks and where AVS / dedicated protection is appropriate
- Functional tests before commissioning and handover documentation
Conclusion
Don't leave a multi-million shilling investment to chance. Proper surge protection usually adds less than 5% to a project's cost but can prevent far more expensive failures. If you are planning solar, include protection and earthing in the design conversation from the start, not as a last-minute add-on.