DTHC not working

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blucllrplt
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Joined: Tue Mar 27, 2018 12:52 am

DTHC not working

Post by blucllrplt » Sun Oct 06, 2019 8:47 pm

Having trouble with my DTHC not working. Unit has worked fine for the past year and went out to start cutting a job this afternoon and the DTHC does not work now. The Sensor PWM II lights indicate both voltage in and Torch on but on the CNC command interface I do not show any volts and I cannot select the DTHC radio button on. When cutting the cnc interface only shows 0 volts. The unit responds properly to Z axis commands, touches off properly and fires the torch. I cannot select any of the DTHC options.

The CNC hub utility only shows that the Hypertherm plasma is connected and nothing else.

What I have tried:

Multiple reboots of all electrical parts
Used a low pressure electrical "duster" to blow out every ethernet port and inside the CNC console
Multiple ethernet cables
Different cut profiles
Reloading the cut profiles and making sure all boxes properly checked in sheet cam

I did not do anything different from yesterday to today. I unplug all electrical appliances every night to help prevent any possible electrical surges.

djreiswig
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Re: DTHC not working

Post by djreiswig » Sun Oct 06, 2019 9:26 pm

Do you have the power light on in the middle of the dthc board? Mine died suddenly like that. Got a new board and had mine repaired.
If it isn't showing up in the hub utility then that's my guess.
2014 Bulltear (StarLab) 4x8
C&CNC EtherCut
Mach3, SheetCam, Draftsight
Hypertherm PM65
Oxy/Acetylene Flame Torch
Pneumatic Plate Marker, Ohmic, 10 inch Rotary Chuck (in progress)

blucllrplt
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Joined: Tue Mar 27, 2018 12:52 am

Re: DTHC not working

Post by blucllrplt » Mon Oct 07, 2019 7:19 am

Will check that right now. Thanks for the tip. Will check and report back!

blucllrplt
Posts: 24
Joined: Tue Mar 27, 2018 12:52 am

Re: DTHC not working

Post by blucllrplt » Mon Oct 07, 2019 8:23 am

All lights work on the board and on the Ethernet plugin showing DTHC is available but the button on the command console is still not available. Will have to call the support line later.

blucllrplt
Posts: 24
Joined: Tue Mar 27, 2018 12:52 am

Re: DTHC not working

Post by blucllrplt » Mon Oct 07, 2019 11:33 am

Further info if anyone has any ideas to share.

I started again at the beginning of the manual to cover every step. For whatever reason the DTHC is communicating with the utility hub now.

Under device details for the DTHC 5 shows the Firmware version is 1.0
At the bottom of the same screen under CandCNC Hub connected it shows the firmware version to be 1.7
Tried to update the firmware per the manual - Popup box states firmware file not valid or not correct.

During the voltage checks, voltage divider set to the Hypertherm setting (50:1) and when I press the test button the voltage reads 126 per the manual. If I try to cut with this setting the torch will dive into the material. Playing around with the adjustment pot, if I set it to 111 volts the torch will not dive into the material with the settings from the defaults provided from Hypertherm.

Still waiting to be accepted into the CandCNC support forum so can't seek answers there, hoping someone out there has some insight.

tcaudle
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Re: DTHC not working

Post by tcaudle » Tue Oct 08, 2019 10:13 am

Our Webmail you sent with the same info will be answered. If you are dinking with the voltage adjustment pot on the DTHC you are already in trouble.
The Initial Cut Test on page 85 of the DTHC manual should point out any issues and let you narrow it down . Now that the DTHC is out of calibration you neeed to follow the PWMII instructions off the Website and set it back to what is correct : 126 with Volts test on and voltage input (2 wire) unplugged.

blucllrplt
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Joined: Tue Mar 27, 2018 12:52 am

Re: DTHC not working

Post by blucllrplt » Thu Oct 10, 2019 5:15 pm

Starting at the beginning of the manual and made a test rig to make sure the voltage divider was correct. Using a 1.5V battery I observed 75V on the display which is correct. However when I reinserted the two prong male plug into the PWM I noticed the wire on the end of the resistor was broken. I can’t make out the color on the first band. I believe the colors are Brown - Red - Black and Gold. It looks like a 1/2 watt resistor. Can you advise the proper resistance and wattage so I can order a new one?

tcaudle
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Re: DTHC not working

Post by tcaudle » Thu Oct 10, 2019 11:11 pm

Is not a resistor if its in the cable , it is a 1000 uH axial choke (inductor) . There are two , one on each wire. Anything from 900 to 1200 uH will work. I would buy more than one since you will have to cut the heatshrink off to replace the part and it might damage the other side.

thefabricator
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Joined: Fri Apr 20, 2018 12:13 am

Re: DTHC not working

Post by thefabricator » Sun Oct 13, 2019 8:14 pm

I use to have these problems with my old CandCNC setup,

Since moving to PlasmaC and using a Mesa THCAD10 as my THC I do not have any problems with THC what so ever. Whats more is it is a very basic system. Simple to install and set up and simple to config.

I once had a lightning strike at our facility and it fried my DTHC IV board. Now with the Mesa THCAD10 I have 2500V galvanically isolated inputs on the card. Probably wont survive a direct lightning strike but should have a good chance of surviving what the DTHC IV card could not. Also a Mesa THCAD10 retails for $69.00 USD compared to the DTHCIV card at $500 USD.

tcaudle
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Re: DTHC not working

Post by tcaudle » Sun Oct 13, 2019 9:44 pm

The THCAD10 is not a THC . It's the remote isolated voltage A to D module, and is equivalent to the PWMII module that has opto isolated (2500 volt isolation.) and an isolated DC-DC power supply . It uses voltage to frequency conversion (versus Pulse Width Modulation and sends its via opto isolators. The torch height is handled via internal software in Linuxcnc. You need other interface cards like the Mesa 7i92 to have a full system. I am sure RodW will jump in and extol the virtues of the THCAD10 and Mesa I/O cards and LINUXCNC, but is not accurate to say its a quick and easy solution for a Windows MACH 3 based system. Something on the back end has to take the frequency sent by the THCAD10 back to a value a processor can read .

thefabricator
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Re: DTHC not working

Post by thefabricator » Mon Oct 14, 2019 12:16 am

Thats exactly right, Its not a THC, its a non proprietary way to read arc voltage. It is the interface between the plasma unit and a CNC controller for the THC. All of the torch height control is done internally through the controller, Just like Hypertherm does it at a much much less steeper price. The other interface card is the breakout board for the system. One other board. Only one other thing that can go wrong apart from motor drives, power supply and some relays.

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