THC acting up

[Alex S.A]

Dear Sirs,
See if someone may help me to get a solution for one problem.
I gotta a problem with a THC control that it doesn't correct the position when it needs to decrease its position, I meant to say, If the voltages goes up the device should to low o corrct its position but it couldn't, but when the voltages drops the device can correct the voltage by elevate the torch. This happens in automatic mode. In manual mode I can control the lifter by goes up and goes down.
Does anyone get a similar problem? If so, how did you solve the problem?

[jcc3inc]

Sir,

If you can move the torch up and down manually (with the switch),but the system when cutting does not respond, then there is a fault with the auto torch height circuit. Without having the complete circuit available, it is hard to tell why it is not operating as it should.

Your torch height control must sense tha arc voltage, compare it to a reference, amplify the difference, then drive the torch motor up and down. Also, the circuit likely will not operate if the arc voltage is too high or too low, and may need other inputs to allow it to operate.

Likely the best source of information will be the manufacturer of the THC.

Regards,
Jack C.