THC Raw Voltage Feed- burnt out plug (Solved)

CrossFire ® General Discussion
1

Hello,

I have a crossfire (only just got it going without THC)
Works great.

Now I am trying to fit a THC Controller.
I am grafting on a Starfire system I acquired.

All was going well until I tried to get Arc Voltage off the machine
(literally off the back of the torch/earth)

What happened was I tried a cut and it burnt out the plug going to the THC board.

Is this because the gauge wire I used was too thick?
I used the same sort of screw in plug used to control the torch.
My THC board can accept 1:1 voltage.

Any help appreciated.
thanks

2

Wire size being too thick is unlikely the issue.

Which plasma torch are you using?

And you’re running raw voltage from the CPC Port of the plasma? Or are you running them from the inside of the machine?

And the wire that burnt off is going into the little black box VIM ( voltage input module.)

image10 (1)
image10 (1)1360×618 79.4 KB

Or do you mean it actually burnt the plug out on your THC board.

image12

THC
THC1999×1657 422 KB

Can you take a picture and post what connections you made on your machine and where the damages.

Are you using an aftermarket THC? If so what’s the make and model.

3

Hello Tim.

Great reply.
If I was using a Langmuir THC setup I would not have this issue.

The plasma source is a cheap Plasmargon with pilot arc.
Soldered a wire onto board, where torch wire meets board on plasma.
Wire going to earth clamp just wedged in Dinse plug.

2 wires then went to board through metal housing via plastic plug which seemed to arc inside and burnt out.
Nothing else seems to be damaged.

I will get pictures later.

This is a problem of my own creation and the Langmuir supplied parts all work perfectly.

4

I though starfire was crossfire spelling autocorrected…

is this the after marker system you are using?

starfire-sf-hc25k-thc-plasma-height-controller

http://hkw222a86.pic42.websiteonline.cn/upload/SF-H25G.pdf

starfire-sf-hc25k-thc-plasma-height-controller is that the right model number?

was it burnt of the left hand side?

thc board starfire
thc board starfire814×457 328 KB

Which Crossfire are you using? Running Mach 3 or Firecontrol?

Is this the plasma cutter?

71IUVneEj-L.AC_SL1430
71IUVneEj-L.AC_SL14301419×1387 163 KB

What is the model number?

5

Hello,

Controller looks just like that.
Will check model when I am home.

EDIT: I dont have a voltage divider though.
You can swap pins on board for it to accept 1:1 voltage which I did.

Mach 3.

Thats the Plasma machine PLC55Pro is model.

thanks

6

711fuINJsPL.AC_SY355

I like the image with the CNC plasma with a oxy fuel torch :roll_eyes:…

Is the StarFire OK with High Frequency interference??

High Frequency used with torch height control and CNC products is known recipe for troubles.

1 Like
7

I didnt think it was HF. since it said CNC compatible.

In your pictures you show a white box, thats all I have.
I dont have the green circuit board, which I thought was a voltage divider.
Which I didnt think I needed since it said it would take 1:1 voltage.

8

71Kvea92X9L.AC_SY355

It is high frequency the torch is a dead give away.

1 Like
9

I see.

So I need to get hold of the voltage divider board?
This filters the HF as well?

thanks

10

were did you hook up the arc voltage from the plasma ?

thc board starfire 2
thc board starfire 2950×652 40.5 KB

I linked the manual up above

11

If only mitigating EMF was that easy… sadly no

1 Like
12

Actually mines slightly different as it has connector for ARC Input 1:1 + and -

Will try and find exact manual.

1 Like
13

This is a good article of plasma cutting and high frequency.

Plasma Cutters for Hobbyist CNC Tables

HF-1 small
HF-1 small2484×2266 200 KB

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14

Thanks.

This plasma works fine with THC I added turned off.
So does that mean HF is not causing an issue for me?

I have seen others use this machine

15

The PLC55pro with the Starfire controller?

I am saying HF can cause issues with electronic systems.

But it is unlikely the cause of your burnt wires.

Lets check how its hooked up .

1 Like
16

I dont know what THC others are using.

17

I have requested exact manual for my THC, will report back.

I sort of assumed the THC board would read voltage like a multimeter and be safe.

So I was surprised when plug started melting, but maybe its only a low voltage plug.

18

this is what i am thinking too.

19

My guess is that it is wired wrong causing the plug to start to melt. You can not use the positive and negative torch connections on a HF plasma cutter to get voltage readings for the THC to work. What happens is it wants to jump an arc between the + and - of the connector the same as it does between the - electrode and + cutting tip .

Most CNC plasma tables with THC and HF use Ohmic sensing for readings.

4 Likes
20

Happy to say this issue is now solved and THC working correctly, phew.

Turns out the plug I was using was only rated to low voltage, and this is why it shorted.

Now I am working on finding good settings for THC.

thanks for help

1 Like