Hobart 40i THC + torch on splicing Guide

Torch height controller (Black torch lead to center post and red clamp lead to right-side post ).

and also remote torch on and off wiring for Hobart 40i

Torch firing is verified working , the torch Height controller THC . I just hooked in. pretty sure t’s right . Traced the clamp return wire to the right-most terminal, and the center terminal must be the primary voltage lead to the torch, since it sends 6 identical wires down that way. Wish me luck .

Update: it worked as expected. Wiring is correct for Hobart 40i
Final Image shows the torch fire wires are the orange and purple wires coming from the white plug near top left of green main board. Behind this bundle, are the main voltage lines for the THC. as in photo, THC Black lead to center, red lead to right-side post. THC makes ALL the difference with thin material!

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Thanks for the info!! I have a Hobart27i - and wiring looks similar but I’m very nervous about the instructions from Langmuir. They say follow the clamp lead for the negative and the positive hooks to the torch lead.

In your photo - is the work piece clamp wire to the post on the right?
It looks like you hooked the THC red wire to this post and the black THC wire to the middle.
Is this correct?
Thanks -

Yes, black (torch) lead to center post, red (clamp) lead to the right post. I actually traced the clamp lead with a multimeter to get right, the torch lead just simply could not have been any other connection. have made 100 cuts so far with this wiring, works great, really like my Hobart Plasma!

Thanks a bunch! I too did a multimeter check and there’s continuity between the two outside posts when power isn’t on. DIdn’t know if that would change at power up what with a “torch red, work black, torch white” post labeling. Langmuir instructions pretty clear - but Hobart has two possible posts on the torch side, however, there’s continuity with one to the ground clamp connection - so what you said confirmed what I though. Again - thanks. Can’t wait to get
this thing finished - and up and running.

OK - Update. Before applying power to this thing, I decided to call Hobart tech support for the 27i just to make sure that there’s no difference between the 40i and the 27i. There is some differences.

Hobarts have a TORCH RED, a WORK and a TORCH WHITE connection. The WORK connection (27i) is the center post. This connection has a jumper to TORCH WHITE (right post) with a round disc type resister filter device. Jumpers usually mean continuity…WTH right? But without power - there’s none here.
But there IS continuity between TORCH RED and TORCH WHITE. WTH again?
This is normal when the machine is off due to the electrodes in the torch touching when no air is present.
Hobart tech says OUTPUT voltage is measured on/from TORCH WHITE. Giddy up.

RAW voltage hookup are opposite. The 40i must have different post locations.
Langmuir’s instructions for Raw voltage hookup specify the THC CLAMP connection (red wire) goes to the clamp wire - (WORK post on the 27i) and the THC TORCH connection. On the 27i, Black wire goes to the TORCH WHITE post of the 27i - opposite of the photo for the 40i above.
I’ve got a question into Langmuir about this because according to Hobart the 40i connections are identical to the 27i. My clamp wire clearly goes to the center post. I’m gonna go with the Red wire to the WORK post and the black wire to the TORCH WHITE on my 27i. Hopefully the sparks will be controlled and limited to the torch head.

Is there a video online anywhere of this? It seems fairly simple but with what we spend on these I want to be sure it’s correct.

@reallycheapgeeks do you have a picture with the cover on? Did you have to notch the cover to keep from pinching the cables? It looks like you ran the crossfire cables through the shoulder strap slot?

I would also search for Miller spectrum 375 info .
this hobart 40 i is a near clone of it .