Most homes in Kenya run on single-phase power — one live wire delivering power in a single continuous wave. Factories, larger commercial buildings and anything with substantial motors almost always need three-phase power instead. If you're setting up or expanding a factory floor, understanding the basics of three-phase supply will help you ask the right questions before signing off on any installation.
What three-phase actually means
Three-phase power delivers electricity through three separate live conductors, each carrying power in a wave offset from the others by a third of a cycle. The practical effect is a much smoother, more continuous delivery of power compared to single-phase, and the ability to deliver far more power through cabling of a similar size. It's why virtually every industrial motor, large compressor, and heavy commercial air conditioning unit is designed to run on three-phase.
Why motors specifically need it
Large electric motors draw a heavy surge of current the moment they start — often several times their running current. On single-phase supply, that surge can dim building-wide lighting and trip breakers. Three-phase motors start more smoothly, run more efficiently, and can be built smaller for the same power output, because the three offset waves keep torque more constant through each rotation instead of pulsing on and off.
Getting a three-phase connection
Not every plot has a three-phase connection available at the boundary; in some cases it needs to be applied for and installed by Kenya Power specifically, which can take longer than a standard single-phase connection and needs to be factored into any project timeline early, not as an afterthought once equipment has already arrived on site.
What a correctly designed three-phase installation includes
- Load balancing across all three phases, so no single phase is overloaded while others sit idle
- Correctly rated panel building — breakers, contactors and busbars sized to your actual equipment, not a generic template
- Motor control gear such as soft starters or variable frequency drives where large motors would otherwise strain the supply on starting
- Earthing and protection sized for industrial fault currents, which are far higher than domestic ones
- A single-line diagram documenting the whole system, for your records and for any future maintenance or inspection
Common mistakes we see on factory floors
The most frequent issue isn't the three-phase supply itself — it's uneven loading, where machinery gets connected wherever a socket happens to be free rather than being balanced deliberately across the three phases during design. Left unaddressed, this shortens equipment life, causes nuisance tripping, and wastes energy. A proper load audit at the design stage, not after installation, is what prevents it.
Three-phase power is only as good as the panel design behind it. The supply is rarely the weak link — the distribution board usually is.
If you're scoping a new industrial site or expanding an existing one, we design the single-line diagram and panel layout before any cable is pulled, so the installation is signed off once, correctly, rather than reworked after the fact.