djsfantasi
- Joined Apr 11, 2010
- 9,156
In the chart I posted above, 22g Kanthal wire is 1.31Ω per foot.Amazon specs are tricky at best, just plain wrong at worst! In your case, it's a single product listing for multiple wire sizes, and the specs should be different for each wire size, but they haven't given you that. Here's one example of info showing resistances (per inch) vs. wire gauge:
Kanthal Wire Gauge (AWG) in Resistance (68°F)
You can see that the resistance gets lower with larger wire diameter. This list didn't go up to 22 gauge, but at 24 gauge it's already down to 2.04 ohm for 1 foot. So, your presumed resistance for the heater is probably off by a factor of 5 or more!
- 24 Gauge (AWG) = 0.17 Ω / in.
- 26 Gauge (AWG) = 0.28Ω / in.
- 28 Gauge (AWG) = 0.44 Ω / in.
- 30 Gauge (AWG) = 0.70 Ω / in.
- 32 Gauge (AWG) = 1.09 Ω / in.
- 34 Gauge (AWG) = 1.76 Ω / in.
It's tricky to do any electronics project without a multi meter, but especially so when you're trying to handle any kind of real power. We might be able to walk you through this particular issue based on specs alone, but I'd STRONGLY urge you to get a meter and start checking your components before using them in the future.
The other lesson here is to be very careful when reading specs, and even more so if you're getting specs from anything other than the product datasheet. Reputable suppliers like digikey, mouser, allied, etc. usually (but not always) get specs right, but Amazon and eBay specs are nearly worthless, and I've heard that Ali Express and other similar sites are even worse. Trust nothing, and verify everything!