FAQ
TL;DR: Expect a small budget impact: “it will be 2–3% of the total cost.” Plan three‑phase if you want an induction hob and room to grow. [Elektroda, retrofood, post #16639387]
Why it matters: This FAQ helps flat renovators decide if, when, and how to switch from 1‑phase to 3‑phase without surprise costs.
Quick Facts
- Single‑phase supplies are typically limited to 25 A, which is tight for an induction‑equipped apartment. [Elektroda, mawerix123, post #16639276]
- Overall cost impact for a switch during renovation is about 2–3% of the project budget. [Elektroda, retrofood, post #16639387]
- Scope may include new switchgear and feeder (WLZ) when moving to three‑phase. [Elektroda, CYRUS2, post #16639410]
- Administrator/owner approval comes before utility (ZE) paperwork and works. [Elektroda, zbich70, post #16639534]
- You can avoid wall‑chasing by routing cable in surface trunking along the staircase. [Elektroda, retrofood, post #16639610]
Is switching from 1‑phase to 3‑phase a major cost in an apartment renovation?
No. When planned within a full renovation, contributors peg the upgrade at roughly 2–3% of the total project cost. That figure assumes you’re already updating circuits and finishes. It excludes unusual building requirements set by the property manager. “It will be 2–3% of the total cost.” [Elektroda, retrofood, post #16639387]
Do I really need three‑phase power for an induction hob?
Yes for comfortable headroom. On a single phase you won’t get more than 25 A, which is not enough to power an apartment with induction and other loads. Three‑phase spreads demand and reduces nuisance trips. It also future‑proofs for electric ovens and dryers. [Elektroda, mawerix123, post #16639276]
What approvals come first: building manager or the utility (ZE)?
Start with the property owner or building manager. With their written consent, apply to the utility for connection conditions and any power increase. Skipping this order can stall your project. Site verification by an electrician is recommended before paperwork. [Elektroda, zbich70, post #16639534]
Will I need to replace the apartment switchgear or WLZ when moving to three‑phase?
Often yes. Expect a new or re‑configured distribution board, updated protective devices, and a compliant main feeder (WLZ). If your flat already uses a TN‑S (three‑wire) setup, the change is simpler. Confirm on site before ordering hardware. [Elektroda, CYRUS2, post #16639410]
What actually drives the bill: connection fees or building works?
Either can dominate. If the staircase or common areas must be opened and restored, that civil work can exceed the connection fee. Clarify routing early with the manager to avoid rework. Get restoration costs in writing. [Elektroda, zbich70, post #16639471]
How can I avoid ripping open staircase walls for the new feeder?
Run the cable in a surface‑mounted channel fixed to the wall. That approach minimizes dust, speeds installation, and keeps restoration costs low. One poster did this in about an hour with basic materials. It’s neat and reversible. [Elektroda, retrofood, post #16639610]
Can I run an induction hob on single‑phase if I’m careful?
Possible, but restrictive. Some hobs limit draw electronically, yet other appliances will compete for the same 25 A. You may need load‑shedding and face performance limits. If renovating anyway, three‑phase is more practical. [Elektroda, Zbigniew 400, post #16639637]
What if the administrator insists on WLZ modernization before extra power?
Be ready to comply. Administrators can require WLZ upgrades before approving added load. Without that approval, the project stalls. This is a common edge case that stops timelines cold. Plan contingencies and timing. [Elektroda, zbich70, post #16639736]
Three‑phase during a renovation: is it really the best path?
Yes. “In a renovation situation, the only good solution is to replace the installation with a 3‑phase one.” It improves functionality, balancing, and future appliance support. It also reduces reliance on load‑priority gadgets. [Elektroda, retrofood, post #16639644]
How much did others actually pay to switch?
Reported outcomes range from a few hundred PLN to several thousand PLN, depending on scope and building rules. Variables include WLZ path, board replacement, and restoration. Get two quotes: electrical and civil. [Elektroda, zbich70, post #16639534]
What is TN‑S and why does it matter here?
TN‑S is a system with separate protective earth and neutral conductors. If your apartment already uses a TN‑S three‑wire arrangement, the three‑phase change is simpler and cheaper. Ask your electrician to verify before design. [Elektroda, CYRUS2, post #16639410]
Can I pull my own five‑core feeder without admin consent?
No. “You cannot do anything without the approval of the administration.” In many buildings, ZE requires that written approval before connecting supply. Plan time to obtain and file this consent. [Elektroda, CYRUS2, post #16640830]
How do I request a power increase the right way?
Follow three steps: 1) Get written consent from the property owner/manager. 2) Apply to ZE for connection conditions and increased capacity. 3) Schedule an on‑site electrician visit to align scope. Keep copies of all approvals. [Elektroda, zbich70, post #16639534]
Could civil works still cost more than the utility fees?
Yes. If you must open common‑area walls and restore finishes, those works can surpass the connection fee. Plan routing to minimize invasiveness and set expectations with neighbors and management. [Elektroda, zbich70, post #16639471]
What if I believe the administrator should fund WLZ replacement?
Common feeders are not privately owned. Press the administration to plan the upgrade instead of self‑funding building assets. Attend meetings and document requests to move it forward. [Elektroda, retrofood, post #16639853]
