12/07/2026
Before installing a solar-powered backup system, sapha electrical engineering services conducts a pre-installation electrical infrastructure assessment.
One of the most important parts of this assessment is what we call "hunting".
What are we actually hunting for?
When you engage us to design and install your solar system, we don't just size the panels, inverter and batteries. We also evaluate the health of your existing electrical installation.
One of the 7 key measurements we take is voltage under both OFF-load and ON-load conditions.
For example, if Kenya Power supplies your premises at 234 V, we record that voltage at the intake point and then systematically measure voltage throughout the installation, all the way to the final circuits.
A typical set of measurements might look like this:
Main intake: 234 V
Distribution Board A: 232 V
Distribution Board B: 230 V
13 A socket outlet: 230 V (off-load), 229 V (on-load)
We then investigate any unexpected voltage drop that cannot be explained by the cable length, conductor size and connected load.
Possible causes include:
1. Undersized conductors.
2. Excessively long cable runs.
3. Loose or corroded terminations.
4. Overloaded circuits.
5. High-resistance joints.
6. Poor-quality or damaged cables.
7. Deteriorated switchgear or isolators.
The voltage drop itself is not the fault—it is a symptom of excessive impedance somewhere along the supply path.
Why is this important before installing solar?
A solar inverter becomes another source of power connected to your existing electrical system. If that wiring already has excessive impedance, the new solar installation may inherit those problems.
The consequences may include:
1. Reduced inverter performance
The inverter may experience greater voltage drop under load, affecting its ability to regulate the output voltage.
2. Excessive voltage rise
During periods of high solar generation and low demand, voltage rise across high-impedance cables can cause the inverter terminal voltage to exceed its protection limits, resulting in nuisance trips.
3. Increased cable losses
Higher resistance means more energy is dissipated as heat instead of being delivered to the load.
4. Poor performance of sensitive loads
Equipment such as refrigerators, pumps and compressors may experience greater voltage drop during operation, leading to longer running times or reduced performance.
5. Reduced fault current
High circuit impedance can reduce prospective fault current, affecting the operating times of protective devices and compromising protection coordination.
6. Incorrect diagnosis
Customers may assume the solar system is faulty when the actual problem existed in the electrical installation long before the solar system was installed.
Our philosophy
At Solar Magics firm we believe that a solar installation should never be used to compensate for deficiencies in an existing electrical installation.
Before commissioning any solar system, the existing wiring should be assessed for:
1. Acceptable voltage drop.
2. Sound electrical connections.
3. Correct conductor sizing.
4. Adequate protective devices.
5. Proper earthing and bonding.
Only after confirming that the electrical infrastructure is fit for purpose should the solar system be integrated.
A well-designed solar system begins with a healthy electrical installation. That is why our pre-installation electrical infrastructure assessment is just as important as the sizing of the panels, inverter and battery.
