Cookie beállítások

Weboldalunk funkcionális, statisztikai és marketing sütiket használ, melyek adatai harmadik felekkel is megosztásra kerülnek.
Részletes adatvédelmi tájékoztató

Cabling: cross-section, length, voltage — thicker is not always enough

8/27/26

Why voltage matters

On the AC side at 230 V: 1% drop is small. On DC at 30–40 V operating point, 2 V drop is already power loss and MPPT disturbance. Long cable + high Imp = larger cross-section needed.

Quick cross-section estimate

Know Imp, distance panel–device, target max 2–3% drop on Vmp:
  • 10 A, 10 m: often 4–6 mm² DC (not 2.5 mm² extension cord cable).
  • 15 A, 15 m: 6 mm² or more — calculate, don't guess.
  • Parallel branches: calculate with branch Imp, not total marketing W.

MC4 and polarity

  • Only proper MC4 pairs — not homemade pressed old types.
  • Check polarity with a meter before connecting.
  • Do not pull connectors tight — mechanical stress + water.
The factory 3 m "solar cable" is often short — extension cable follows the same rules as the string.

Underground routing

If DC cable runs underground: proper outer diameter, water, UV, mechanical protection. In plug-and-play setups, ground mount → short underground section to the device — do not use thin flex long term.

What to check in operation

Hot connector, discoloration, drop at evening peak — may signal too thin cable or bad MC4.

Want to calculate with your own numbers?

Registration gives you access to the compatibility and cable calculators, plus new articles when we update the device database or walk through a new panel type.
Register

Don't stay on the manufacturer's datasheet alone

Registration brings new articles: realistic numbers, cold Voc, panel choice, calculator updates. No affiliate, no "top 10". No spam — only when there's new content.
Registration — more info

Important

This article is for information and brainstorming purposes. It is not electrical, engineering, or legal advice, and it does not replace a qualified professional or local regulations.
Portable power station, extension-cord, and "plug and play" solutions have limits. What we describe here is based on our own experience and general technical considerations — your panel, device, cable, and site may differ. A poorly calculated voltage (especially in cold weather) can cause permanent damage without warranty coverage.
Working on electrical equipment can be life-threatening and is often not a DIY job. If you are unsure, or the work goes beyond extension-cord use (fixed wiring, earthing, RCCB, household grid), stop and hire a professional.
The calculations, examples, and calculators shared here are not guarantees of yield, payback, or safety. Implementation, risk, and consequences are yours.
Do you have a question? Need a quote?
Feel free to contact us regarding accounting, payroll, taxation, or any other business matters by phone, email, or in person. Our colleagues will respond to your inquiry shortly. Get in touch with us. Request a written quotation now, or call us using one of the contact details below!
Request a written quote now! Or feel free to call us using one of the contact details below!
📞 Phone: +36 1 422 0753
📱 Mobile: +36 20 499 5210
✉️ info@robotvilag.hu