What is Ampacity?
Imagine a water pipe.
- Water = Electric current
- Pipe = Cable
If too much water flows through a small pipe, the pipe will burst 🚿💥
Same way…
If too much current passes through a thin cable → the cable overheats & can burn 🔥
So,
Ampacity = Maximum current a cable can safely carry without overheating
🧠 Why does cable heat?
When current flows, the wire has resistance → creates heat 🔥
More current = More heat
A bigger cable has:
✔ Less resistance
✔ More surface to release heat
→ It can carry more current safely
👀 Quick Example
| Cable Size | Max Safe Current (Ampacity) |
|---|---|
| 1.5 mm² | ~14 A |
| 2.5 mm² | ~21 A |
| 4 mm² | ~28 A |
| 6 mm² | ~36 A |
If your load takes 25 Amps, and you choose…
- 2.5 mm² cable → ❌ will overheat
- 4 mm² cable → ✅ safe!
That safe limit = Ampacity
🧩 Memory Trick
Ampacity = Cable Strength
Like a person lifting weight:
- Thin cable = weak = small current only
- Thick cable = strong = more current allowed