Rex-c100 and Nichrome

[omar587]

Hi Guys, so i'm building a thermoforming machine for pet plasctic it will heat up to 160 degrees Celsius, for the heating element i will use a nichome
NI90 wire and to control the temperature i will use a REX-C100, SSR-40A Relay and thermocouple type-K

So my question is do i need a seperate power supply to heat up the nichrome or will the REX-C100 do the job like the image i linked bellow.
Thanks

 

[Bluejets]

Your question raises many other questions....be more specific on equipment intended to be used, and just what is "thermoforming machine for pet plasctic"
Note the extreme danger of using a nichrome wire on mains supply, there are much safer ways.

 

[davenn]

So my question is do i need a seperate power supply to heat up the nichrome

Note the extreme danger of using a nichrome wire on mains supply, there are much safer ways.

agreed

I wouldnt even consider using mains voltage to heat the wire, way too dangerous
Use a DC supply at a much lower voltage

 

[omar587]

Yes, you're absolutely right—this can be dangerous, which is exactly why I created this thread and sought your advice. I want to make sure I don't do anything reckless and end up causing damage.

The area where the Nichrome wire will be placed measures 229 mm by 317 mm, giving a surface area of 0.072573 m².

I'm planning to arrange the Nichrome wire in a zigzag pattern. The wire is N90/23G with a resistance of 0.09Ω per inch.

Right now, I'm trying to determine the appropriate length of Nichrome wire I’ll need and whether I should power it directly from the main power supply or use a separate one.

 

[Delta Prime]

appropriate length of Nichrome wire I’ll need

Hotwire Calculator

 

[omar587]

Thank you for the link it's been helpful, after the calculation I've found out that i need 43 inches of Nichrome 90 wire and power supply of 12v 3A, i have a power supply of 12v 16.6A that i will use.

My question is, can i power the rex c100 kit with this power supply? or do i need another solution.

 

[omar587]

Here's what i've figured out, your feedback is appreciated :

• Power the REX C100:
  • Plug the REX C100 into a standard AC outlet (110-240V AC) to provide it with the necessary power.
• Connect the REX C100 to the SSR:
  • The REX C100 will control the SSR using its output terminals. These are usually labeled as OUT+ and OUT- or similar.
  • Connect the positive (OUT+) terminal of the REX C100 to the positive control terminal (often labeled as A1 or 3) on the SSR.
  • Connect the negative (OUT-) terminal of the REX C100 to the negative control terminal (often labeled as A2 or 4) on the SSR.
• Connect the SSR to the 12V Power Supply:
  • The SSR has load terminals typically labeled as T1 and T2 (or 1 and 2). These terminals control the high-current flow from your 12V power supply to the Nichrome wire.
  • Connect the positive terminal of your 12V 16A power supply to T1 on the SSR.
  • Connect T2 on the SSR to one end of the Nichrome wire.
  • Connect the other end of the Nichrome wire back to the negative terminal of the 12V power supply.
• Final Wiring Check:
  
  • REX C100 Output Terminals: Connected to the SSR control side (A1 and A2).
  • 12V Power Supply: Connected through the SSR (T1 and T2) to the Nichrome wire.

 

[Bluejets]

43 inches of Nichrome 90 wire and power supply of 12v 3A

Having used nichrome wire to cut rc aircraft wings for many years, I think , given this past experience, that 12v will be insufficient.
The longer and greater the load, the higher the voltage will need to be.
e.g. for a nichrome bow using 20g I was using 40v at 120va transformer and a primary dimmer for any fine adjustment.
Tends to be a suck it and see arrangement regardless of any "calculator".
Also be aware that trying to control any area temperature around your heater will have a certain amount of hysteresis.

Your application is rather vague but given what I suspect you are trying to achieve, perhaps a "hot air" gun might be more appropriate.

 

[Delta Prime]

NI90 wire

My question is, can i power the rex c100 kit with this power supply? or do i need another solution

Yes.You can power the RX c100 kit with this power supply.
I have used tungsten and Ni-80 and Ni-90 and ka1
Which is a iron chromium aluminum alloy (FeCrAiA1)
With an approximate length as yours I had no problem using 12 volts at 6 ampsfor Ka1 that has a far higher resistivity then
Ni-90. You have done your homework! Thank you for starting this thread.

 

[omar587]

Having used nichrome wire to cut rc aircraft wings for many years, I think , given this past experience, that 12v will be insufficient.
The longer and greater the load, the higher the voltage will need to be.
e.g. for a nichrome bow using 20g I was using 40v at 120va transformer and a primary dimmer for any fine adjustment.
Tends to be a suck it and see arrangement regardless of any "calculator".
Also be aware that trying to control any area temperature around your heater will have a certain amount of hysteresis.

Your application is rather vague but given what I suspect you are trying to achieve, perhaps a "hot air" gun might be more appropriate.

I won’t be heating it that much, only to around 320°F. Based on my calculations, I determined that I need a 47-inch length of Nichrome 80. I used 90% of this length because I couldn't find an option for Ni90 in the calculator.

Are you suggesting that my calculations might be incorrect? Should I switch to a 40V, 120VA transformer as you recommended?

Also, could you clarify what you mean by "a certain amount of hysteresis"? Will the PID controller not be effective for my application in this case?

 

[omar587]

Yes.You can power the RX c100 kit with this power supply.
I have used tungsten and Ni-80 and Ni-90 and ka1
Which is a iron chromium aluminum alloy (FeCrAiA1)
With an approximate length as yours I had no problem using 12 volts at 6 ampsfor Ka1 that has a far higher resistivity then
Ni-90. You have done your homework! Thank you for starting this thread.

Thank you! I’ll definitely give the 12V 16.6A power supply a try. I'll follow the wiring diagram provided, but I want to make sure I’ve got everything right. Could you please verify it before I proceed, just to avoid any potential damage?