FAQ
TL;DR: Only 27 % of Polish flats carry 3-phase 400 V supply [GUS, 2022]; an expert writes “single-phase dominates” [Elektroda, Peter134, post #16874057] Your cabinet shows single-phase; limit an induction hob to ≈5.75 kW or add 3-phase.
Why it matters: Choosing the right cooker and wiring now avoids costly re-work and blown fuses later.
Quick Facts
• Single-phase 25 A service = 5.75 kW usable power (230 V × 25 A) [Elektroda, CYRUS2, post #16875616]
• Typical 3-phase upgrade fee: PLN 1,000–3,000 incl. meter swap [Energa, 2023]
• Induction hob efficiency ≈84 % vs 74 % for radiant ceramic tops [DOE, 2018]
• Minimum cable for dedicated hob circuit: 3 × 4 mm² Cu up to 25 A [PN-HD 60364-5-52]
• Overloading a 16 A plug with 32 A can melt the base, as in the thread case [Elektroda, Dyta, post #16874173]
1. How do I know if my flat has 3-phase ("strength") supply?
Open the fuse board: a 3-phase feed shows three live conductors and usually a 4-pole RCD. The photos posted reveal only one phase and one neutral, confirming single-phase [Elektroda, Dyta, post #16874054]
2. How many wires should emerge behind the cooker outlet?
Three wires (L, N, PE) mean single-phase. Four or five (L1, L2, L3, N, PE) signal 3-phase and allow higher loads [Elektroda, jurex2, post #16874029]
3. Does adding 3-phase always require wall chasing?
Not necessarily. Surface-mounted trunking in skirting or stairwell risers can avoid chiselling, but the building manager must agree [Elektroda, mawerix123, post #16874091]
4. Can a 7.2 kW induction hob run on single phase?
Yes, if the model offers power-limiting. Set it to ≤5.75 kW to stay within a 25 A fuse; many hobs throttle automatically [Elektroda, CYRUS2, post #16874663]
5. What breaker size should protect a single-phase hob?
A dedicated B16 A–B20 A MCB on 2.5–4 mm² cable is common. Above 20 A, select C-curve to avoid nuisance trips [PN-HD 60364-4-43].
6. How much continuous power does a 25 A single-phase service provide?
230 V × 25 A = 5,750 W. Short bursts up to 30 A (≈6.9 kW) may pass before the fuse reacts [Elektroda, CYRUS2, post #16875616]
7. What happens if I overload the pre-meter fuse?
It blows or melts. The OP’s 32 A attempt on a 16 A base burned the plug and cut supply—an avoidable failure [Elektroda, Dyta, post #16874173]
8. Are induction hobs really more efficient?
Yes. Lab tests show 84 % energy transfer versus 74 % for radiant ceramics, saving roughly 10 % electricity per meal [DOE, 2018].
9. Quick 3-step check before buying a hob
- Count conductors at cooker point.
- Read main fuse rating (e.g., 25 A).
- Compare hob’s adjustable power range with fuse limit. If range ≤ fuse ×230 V, you’re safe.
10. Edge case: main plug burns again—what now?
Stop using the circuit, call a licensed electrician, and replace both the base and cartridge with correct amperage. Continuing use risks fire [Elektroda, zbich70, post #16874430]
11. What does a 3-phase upgrade cost and involve?
Expect PLN 1,000–3,000 for utility paperwork, new meter, and breaker board. Additional costs for riser cabling vary by distance and building rules [Energa, 2023].
12. Can I program a hob to never exceed my limit?
Many Bosch, Siemens, and AEG models let users cap input in 1 kW steps—e.g., 3-5 kW max [Elektroda, lukiiiii, post #16875938]
13. Do I need permission to run new cables in the stairwell?
Yes. The housing cooperative or building manager must approve changes in common areas and may request licensed contractor documentation [Warsaw Housing Regs, 2021].
14. What pots work with induction?
Magnetic bases only—check with a fridge magnet. Stainless multi-layer and cast-iron pass; aluminium won’t unless it has a ferromagnetic plate [Manufacturer Guides].