Emergency Power Generators

Emergency power generator — how it works and when you need one

An emergency power generator is an engine-and-alternator unit that takes over supplying a building or a site the moment mains power fails. It produces voltage close to grid supply — 230 V single-phase or 400 V three-phase (3 x 230 V) — so lighting, a central-heating pump, a fridge or power tools keep running without a long interruption. Output is stated in kVA (kilovolt-amperes, the unit of apparent power — real power in kW is usually around 0.8 of the kVA figure). Single-phase home units typically run 2–10 kVA, while three-phase models for business use range from a dozen or so up to several dozen kVA.

In the NORWIT.PL offer, emergency power generators are equipment from FOGO — single-phase and three-phase units, ready for a quick start during a mains outage and for use on site without a permanent connection. The full range of generators from this brand is available on the FOGO page. Below we explain the differences between generator types, how to size the output, and the rules for a safe connection to your electrical installation.

Types of emergency power generators — single-phase and three-phase

The basic split among emergency power generators runs along phase count and start method. A single-phase generator supplies 230 V and is enough for a detached house and household appliances. A three-phase generator produces 400 V (3 x 230 V) and evenly loads three phases, which is essential when powering electric motors and larger business installations. A separate feature is the start method — manual (pull cord) or electric (single push-button) in models built for more frequent use.

One example of a single-phase unit in this range is the FOGO FH line. Exact model specifications (output in kVA, tank capacity, noise level) are shown on the individual product pages or in the full power generators offer.

How to size a generator to your home or business needs

Generator output is sized by adding up the devices that need to keep running during an outage, plus a reserve for start-up current (fridge, pump) — usually an extra 20–30% of the total. A generator that's too small won't handle the start-up load, while one that's too large just burns fuel needlessly.

At borderline values, it's better to pick a generator with slightly higher output than the calculated total — a 15–20% margin protects against overload when several devices start up at the same time.

Safe connection to your installation — transfer switch and phase balance

A power generator must never be plugged directly into household sockets — doing so risks damaging the wiring and causes a shock hazard once mains power returns. A correct connection requires a mains-generator switch, known as an ATS (Automatic Transfer Switch — a system that disconnects the 230 V or 400 V installation from the grid the moment power fails and switches it to the generator, then returns to mains once it's back). Fitting an ATS, or a simpler manual changeover switch, should be done by a licensed electrician and usually takes 1–2 hours. On three-phase generators it's also important to balance loads evenly across the three phases (L1, L2, L3), since overloading a single phase will shut the unit down.

Operation: fuel, run time and maintenance

Fuel consumption depends on output and load — single-phase home units (3–6 kVA) typically burn 1.5–3 litres of petrol per hour, while larger three-phase generators (10 kVA and above) use 4–6 litres per hour. A typical 15–25-litre tank lasts 6–10 hours at an average load. Manufacturers recommend an oil change after the first roughly 20–25 hours, then every 50–100 hours. A generator left idle is best started for 10–15 minutes every few weeks.

Frequently asked questions about emergency power generators

Why buy an emergency power generator at NORWIT.PL

In the emergency power generators category we offer proven units from FOGO — single-phase and three-phase, ready for a quick start the moment mains power fails at home, in the office or on a building site. We advise on sizing the output and phase count to your real needs, and on a safe connection through an ATS. The full range of generators is in the parent category power generators. Orders are fulfilled online, with nationwide shipping.