DTHC Troubleshooting

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TimP
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DTHC Troubleshooting

Post by TimP »

DTHC IV, Hypertherm PM85, Windows 7, Mach3

So, after having done all of the perfunctory tests and research, these are the results -

Press test button on Digital Current Probe, and it gives me the ARC OK light in Mach3.

On the PWM, first test button gives ARC OK light.
On PWM, second test button shows 125 volts in Mach3 on torch test.
The jumper is in the Hypertherm position.

I ran a small test file to cut 16ga running 45Amp tip, 130 volts. It pierces, then torch immediately raises, looking for more voltage, then shuts off. Viewing the torch volts on the Mach3 screen, it starts at 34v, and goes to 54v, then shuts off.

I can run the file just fine when the DTHC is off.
I think I've eliminated the PM85, because I just upgraded to it from a Powermax1000, and it was doing the same thing.

Any other tests, hints, tips, or help? I think it's either the PWM or the HUB (v1.7, the DTHCIV is 1.9). Hoping to narrow it down to one or the other without throwing parts at it.

Thank you for your time!
Tim
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Re: DTHC Troubleshooting

Post by BTA Plasma »

PWM passed test 126v test
DTHC card passed 126v test
Mic 01 wire passed test or it would read over 200
Hypertherm did not. You may need to replace the division board in the Hypertherm

To make sure this is the issue you need to go into your manual to page 3-19 and look at the schematic for the CPC port. Using a OHM meter set to DC VOLTS put the leads across pins 5 and 6, then take a jumper across pins 3 and 4 (On the CPC on the back of the hypertherm) with the torch about 3 inches above the material. If you are reading around 3 volts when the torch is fired the Hypertherm is NOT the issue. If it is less than like .5 volt when the torch is fired then the Hypertherm is the issue.
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TimP
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Re: DTHC Troubleshooting

Post by TimP »

Thank you very much for the help!
Getting .64v at the CPC.

So...I guess ill get in touch with Hypertherm.

Tim
tcaudle
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Re: DTHC Troubleshooting

Post by tcaudle »

like running down the road and your speedometer show 0 MPH and you are try to use cruise control. If its not in warranty then a cheaper solution is to get our RAV-02 voltage divider card and just pickup raw arc volts (two connections) and set the PWM divider to the 7:1 ratio. We have never had one burn out on a Hypertherm.
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TimP
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Re: DTHC Troubleshooting

Post by TimP »

This one is still under warranty, but thank you for the suggestion.
The only thing the Hypertherm tech had me do was to move the torch closer to the material, and actually cut while I was getting the readings. He said firing into the air would not work. One of the pins references the torch, the other references the material. So it actually needed to cut.
I tried it out, and still came up with the .64vdc.
Just some extra knowledge.
Thank you both for your help!

Tim
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Re: DTHC Troubleshooting

Post by tcaudle »

He is working from a procedures book. The open circuit voltage is measured inside the unit between the electrode and the work clamp. That is where the voltage divider is connected .The workclamp does not have to be connected to anything externally. Hold the two leads in your hands and fire the torch.....it will cause your teeth to chatter and your muscles to twitch! (just kidding...DON"T TRY IT)!
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