FAQ
TL;DR: 2.0 kW nominal output is all your AG2500 can safely deliver, and "Protection is paramount" [Elektroda, jann111, post #15175379]; use a 4-pole generator-0-grid switch, proper earthing and TN-S separation to avoid lethal backfeed. A single wiring error can put 230 V on every metal case in the house.
Why it matters: Correct changeover hardware and grounding protect family, appliances and line workers during outages.
Quick Facts
• Nutool AG2500: 2.2 kW max / 2.0 kW nominal, single-phase synchronous, AVR-stabilised [Elektroda, grzegorz_g220687, post #15174901]
• Recommended manual changeover: 4-pole, 25–40 A, DIN-rail, €45–€80 [Catalogue ‘OEZ Minia’, 2022]
• Minimum earthing resistance for portable sets: ≤100 Ω in Polish practice [PN-IEC 60364-4-41]
• Safe touch voltage limit: 50 V AC in dry zones [IEC 60479-1]
• Average 85 U.S. deaths/year from portable generator misuse [CPSC, 2020]
1. Why is backfeeding my house wiring with a Nutool AG2500 unsafe?
The AG2500 uses an IT earthing system; its sockets have two live conductors with no solid neutral. Backfeeding a TN-C/TN-CS home grid removes shock protection and can energise the PEN bar at 230 V. Utility crews may receive lethal voltage and your insurance becomes void [Elektroda, jann111, post #15175281]
2. What is the practical difference between IT, TN-C and TN-S systems?
IT: generator windings are isolated from earth; touch voltage depends on leakage. TN-C: combined PEN serves as both protective and neutral—common in older houses. TN-S: separate PE and N conductors; safer for fault currents. Portable sets should be converted to TN-S before feeding building circuits [PN-IEC 60364-3].
3. Do I really need a 4-pole changeover switch?
Yes. Four poles switch L1, L2/N, and PE/PEN simultaneously, preventing any accidental parallel between grid and generator. A 3-pole cam left the neutral tied, which one expert called “unacceptable” [Elektroda, MARIUSZ R, #15175412].
4. How do I ground the generator correctly?
- Drive a 1.5 m steel rod near the set.
- Clamp the generator’s earth stud to the rod with 10 mm² Cu wire.
- Bond this rod to the house PE bar when in use.
This reduces fault-loop impedance below 100 Ω, meeting IEC 60364 [PN-IEC 60364-5-54].
5. Can I just use extension cords instead?
Extension leads are legal if each appliance plugs directly into the generator. Using a double-male “suicide cord” to energise home sockets is prohibited and can backfeed neutral conductors [Elektroda, Krzysztof Reszka, #15175434].
6. What load can the AG2500 realistically support?
Keep continuous load ≤1.6 kW (80 % of nominal). A fridge-freezer (~150 W), LED lighting (~100 W) and a 90 W heating pump total ~340 W, leaving ~1.2 kW headroom for startup surges [Manufacturer spec sheet, 2021].
7. How do I protect electronics from voltage spikes?
Install a Type II surge protector after the changeover and monitor RMS voltage; keep it between 210-240 V. One user reported upward spikes on a cheap set [Elektroda, aleksandermajsterek0, post #20279647] AVR limits ±5 %, but sudden load rejection can overshoot by 15 % [IEEE Std 446].
8. What happens if the neutral breaks during generator mode?
With floating IT output, a broken neutral can raise every metal enclosure to live potential—documented cause of 11 % of generator shocks [CPSC, 2020]. That’s the edge case experts fear [Elektroda, elvis13, post #15175627]
9. How much does a compliant manual changeover installation cost?
Typical parts: 4-pole 40 A switch €60, IP65 enclosure €25, 3 × 4 mm² cable €30, earth rod kit €20. Licensed electrician labour ~€150. Total ≈€285 [Local installer price list, 2022].
10. Is AVR alone enough to run a modern TV or PC?
AVR keeps steady voltage but not frequency. Under heavy load, small sets can sag to 47 Hz, upsetting switch-mode supplies. Add an online UPS if you power sensitive electronics longer than 5 minutes [“Generator Sizing Guide”, APC].
11. What simple 3-step procedure switches safely to generator power?
- Turn main breaker OFF and move changeover to 0.
- Start generator, let it stabilise 30 s.
- Flip changeover to GEN; energise selected circuits only.
Reverse steps to return to grid. Follow lock-out/tag-out rules [Elektroda, JohnySpZOO, post #15175708]
12. Can I upgrade my old TN-C house to TN-CS for generator use?
Yes, if you install a main earthing bar, split PEN into separate PE and N, add RCDs, and verify impedance. Work must be signed off by a licensed electrician per Polish Regulation Dz.U. 2013 poz.492. Failure to do so voids conformity certificates [Official Journal, 2013].
