hypertherm 65 divided arc signal voltage low
First post here- usually can solve my problems at the Candcnc forum. Have had a Candcnc Wndows setup with a Hypertherm 65 for about 4 years. Recently switched from XP to Win7- having some new problems that eventually sent me here after we narrowed down the problem to possibly being in the actual plasma cutter itself. When I test the voltage at the Candcnc PWM unit (from the plasma divided arc signal board), I get a voltage of .26 volts, which is low by a factor of 10. Should be somewhere around 3 volts, according to the Candcnc moderator. The jumper on the PWM is set at 50:1, and a look inside the Hypertherm shows the dip switch set at 50:1. Any ideas on what's going on? I've got electrical continuity from the PWM all the way back to the small voltage divider card so that seems to rule out any bad/intermittent contact. What I can do to get back up and running?
Re: hypertherm 65 divided arc signal voltage low
Quote:
Originally Posted by
bobowo
First post here- usually can solve my problems at the Candcnc forum. Have had a Candcnc Wndows setup with a Hypertherm 65 for about 4 years. Recently switched from XP to Win7- having some new problems that eventually sent me here after we narrowed down the problem to possibly being in the actual plasma cutter itself. When I test the voltage at the Candcnc PWM unit (from the plasma divided arc signal board), I get a voltage of .26 volts, which is low by a factor of 10. Should be somewhere around 3 volts, according to the Candcnc moderator. The jumper on the PWM is set at 50:1, and a look inside the Hypertherm shows the dip switch set at 50:1. Any ideas on what's going on? I've got electrical continuity from the PWM all the way back to the small voltage divider card so that seems to rule out any bad/intermittent contact. What I can do to get back up and running?
Some background information may stir up a reply- when I was trying to cut with the DTHC on, the torch would rapidly rise, and the cutting voltage would not go over about 20 volts. An error message would appear "torch voltage out of acceptable range" or something to that effect. With the Digital Torch Height Control off, the cuts would nice and clean- the Hypertherm is working fine as far as cutting goes. But somehow the arc signal from the torch is messed up. Either there is a problem of some sort on the main Hypertherm circuit board, or something is screwy in the Mach 3 software- there's just nothing else left to be the culpret. What I'm hoping to get here is some info on the Hypertherm raw arc or divided arc voltage so that I can test it here before I have to send the whole unit or the board to some repair center. Where's Jim Colt when you need him? lol.
Re: hypertherm 65 divided arc signal voltage low
I don't know your cnc controller, plasma cutter or THC software but I have had some funny things happening like that. If you changed your OS than thats what I would suspect. I think I would disconnect the plasma cutter from the CANDCNC hardware and measure the divided voltage output with a multimeter when doing those nice clean cuts.. I have had an instance where the sensing circuit had an impact on the divided voltage. effectively increasing the divided ratio by about 1.5 times (eg fro 50:1 to 75:1).
Without knowing your hardware, so I don't want to blow anything up on you, but the next thing I would try would be to hook up a 3 volt battery to the divided voltage input on the THC. 3 x 50 = 150 volts so it would be interesting to see what Mach reports in that case.
Re: hypertherm 65 divided arc signal voltage low
Thanks based Australian bro. I did what you suggested- used a couple of used batteries and sent 2.7 volts thru the PWM into Mach 3- got a reading of 135 volts on the screen, which is pretty close to expected. That seems to rule out software issues. Also tried making a voltage measurement directly off the main Hypertherm board (marked "jumper 32", which is pre voltage divider card), while making a manual (DTHC off) cut, and got something in the .27 volt range. This seems a crazy low number since it's ahead of the voltage divider card- my thinking is this is where I would be getting raw arc voltage. I'm not a real electronics person, though many times I can see and fix obvious problems, but here I'm at a standstill. Seems like now it's a broken sensor, loose wire or cold solder joint somewhere issue. Possibly a connection in the torch itself? I will say that generally the plasma unit has not been worked too hard, has low hours, and was working fine previous to this. It's inactive most of the time. Also put in new consumables just to be sure.Thanks again for your input- can use more ideas if anyone has them.
Re: hypertherm 65 divided arc signal voltage low
Ok, so you've confirmed your controller and the software are OK, so the next thing I would have checked is the cable for both continuity on every wire (which you seem to have done) and then check that 2.7 volt battery at the plasma end of the cable still gives you 135 volts. Then you will have 100% isolated the fault as being in the plasma cutter so time to talk to a Hypertherm technician.
