Nichrome Wire Calculator: Difference between revisions
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| Line 22: | Line 22: | ||
=Examples= | =Examples= | ||
==8" bed== | |||
*12' of 26 ga draws 450 Watts. | *12' of 26 ga draws 450 Watts. | ||
*This was acceptable, but burns out thermistors if placed directly on heater. | *This was acceptable, but burns out thermistors if placed directly on heater. | ||
| Line 27: | Line 28: | ||
*Keep conservative on the bed power,then. | *Keep conservative on the bed power,then. | ||
*For same power density on large bed (7W/sq in), would need 4000W of heat. Can't do that. Limit is 1800W. the question is how best to achieve it - what length of nichrome is required for a workable length, while keeping temperature lower rather than higher. | *For same power density on large bed (7W/sq in), would need 4000W of heat. Can't do that. Limit is 1800W. the question is how best to achieve it - what length of nichrome is required for a workable length, while keeping temperature lower rather than higher. | ||
==2x2 foot bed== | |||
*1800W limit | |||
*To cover bed - try 6 lines separated by 4" of space. This means 12' + 2 feet return or 14' of sleeve | |||
* | * | ||
=Links= | =Links= | ||
*[[120V Heatbed]] | *[[120V Heatbed]] | ||
Revision as of 20:33, 25 November 2019
- https://www.easycalculation.com/engineering/electrical/nichrome-wire-calculator.php
- Issue - above calculator does not fix voltage
Procedure
- Select convenient length
- Select max temp - such as 550C = 1000F
- Match gauge to proper voltage drop of 120V
- Find out max gauge that is within current limits (15A) and has correct voltage
- Limit for 15A outlet is 1800W
Sample:
- Remains within 15 amps
- Shows correct voltage
- Max temp - select it to match voltage - you determine max possible temp and judge whether it will burn out your system if you have temperature sensitive components
- Note that Gauge 17 is the max fatness that stays within 1800W
- Note: 22' of 18 ga gets us right at 120V, and 1560W. Good. But temperature of 1260F is a little high.
Examples
8" bed
- 12' of 26 ga draws 450 Watts.
- This was acceptable, but burns out thermistors if placed directly on heater.
- Point: the shorter the nichrome, the hotter it will get while remaining at the correct voltage
- Keep conservative on the bed power,then.
- For same power density on large bed (7W/sq in), would need 4000W of heat. Can't do that. Limit is 1800W. the question is how best to achieve it - what length of nichrome is required for a workable length, while keeping temperature lower rather than higher.
2x2 foot bed
- 1800W limit
- To cover bed - try 6 lines separated by 4" of space. This means 12' + 2 feet return or 14' of sleeve