View source for Nichrome Wire Calculator

*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''' - ie, observe parameters that produce 120V drop - those will be the working parameters since 120V is fixed.
*Find out max gauge that is within current limits (15A) and has correct voltage
*Limit for 15A outlet is 1800W

Sample:

[[File:samplenichrome.png]]

*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.

[[File:nichrome2.png]]

=1000F Limit - 240V Case=
[[File:1000c.png|300px]]

=Examples=
==8" bed==
*12' of 26 ga draws 450 Watts, but goes higher than rated 1000F
*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. Use 14' of 26 ga for 380W and 1000F max at 120V.'''
*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
*Gauge 17, 28' long, gets max 1090 and 1570 watts
*sleeve it in 14' of sleeve. Quite doable. needs total of 28 feet of sleeve.
*Selection: 

[[File:finalselection.png]]

Shorten it by 2-4 feet to get max power and temperature.

=Grades of Nichrome Wire=
*60, 80, etc - https://temcoindustrial.com/product-guides/wire-cable-and-accessories/resistance-and-non-resistance-wire/nichrome-wire
*Nichrome A or C - [https://super-metals.com/news/nichrome-a-and-nichrome-c-industrial-heating-wires/]

=Links=
*[[Insulated Heatbed]]
*[[120V Heatbed]]