Thermal Dynamics CUTMASTER 60i Service Manual page 58

CUTMASTER 60i
If there is no gas flow, after a couple seconds the display should show E016. If it does show E016 skip to "d.". If it
does not and it is not an SL100SV (automation) torch then the PS1 pressure sensor may be defective. Skip to "e."
a. If a manual (hand) torch is available install it and if still no purge skip to "d." and continue test.
b. Check for continuity to the torch mounted solenoid. Disconnect J607 and measure resistance on the
harness connector between pins 5 and 7. Normal is between 15 to 25 ohms. If less, the torch solenoid or
wires to it in the torch lead or mounting tube may be shorted. If open the solenoid or the wires in the
torch lead may be open. Disconnect the torch lead from the CM60i and measure between pins 5 and 7 of
the ATC. If still open or shorted replace the torch.
c. If the torch solenoid measures OK reconnect J607 and measure voltage at J607-5(+) to J607-7 or work lead
(common). During the 2 second purge voltage about 22V for ½ second then about 6V for the remainder
of the 2 sec. If not, Inverter board may be defective. Skip to "g." to test for 24V into the Inverter board.
d. After confirming gas is connected to the rear panel, measure J600-5(+) to J600-6(common) or work lead.
A defective PS1 sensor can make it appear that there is enough pressure. With no pressure it should read
near zero volts. If higher, like 3-5V, the sensor is defective. You can also go to the Advanced Features
Menu and select PRES to see what pressure the system thinks it's seeing. See sub section 5.10.
If voltage at J600-5 is near zero:
e. Check that the two wires are connected to the gas solenoid. Remove one (or both) and measure the re-
sistance of the solenoid coil. It should be about 26 ohms +/- 10%. If not, replace the solenoid.
f. If resistance is OK reconnect the coil wires leaving room to measure voltage. The solenoid is controlled
by a pulse width modulated 24VDC. The voltage measured with gas flowing will be an average some-
where between zero and 24V of either polarity, may be + or -, it doesn't matter. Since no gas is flowing,
the voltage should be close to the full 24V. If it is replace the solenoid.
g. If no voltage at the solenoid then the Inverter board may be defective. Confirm that there is 24VDC enter-
ing the Inverter board between J603-1(+) and J603-5 (-) or common at the work lead. If there is voltage
replace the Inverter board. Otherwise check for 24 VDC from the Bias board at J303-1 to common.
i. Other possible cause is the solenoid control signal GAS_PWM at pin 23 of the ribbon from the Control
& Display board.
Pilot & Transfer
At this point all the "startup" initializing procedures have been performed. Refer to the Operating manual or
the "Quick Start "guide to use the front panel controls to select current, cutting mode, torch type and lead length
as well as gas pressure. Set the cutting mode to RUN which is the normal cutting mode. Next step is press the
torch trigger or apply Start if automation unit. This should initiate a short "preflow" of gas which then stops
momentarily and restarts initiating the pilot arc. Bringing the torch near the work should initiate arc transfer
at the selected output current. If this is all OK proceed to testing the other cutting modes. If there is a problem
a fault code is likely to be displayed. Common faults and brief explanation of the fault codes are found in sub
section 5.04 of this manual. We'll cover more detailed troubleshooting in the Fault Code section.
Some faults do not set a code. Look for your symptom here.
1. Gas flows all the time.
a. Unit is set in SET/PURGE mode, change to a cutting mode.
b. Gas inlet pressure is too high forcing the solenoid open. Maximum inlet pressure should be 125 PSI.
Reduce inlet pressure.
c. Solenoid (SOL1) is stuck open. Remove one of the wires to the coil. If gas continues to flow replace the
solenoid.
d. If gas stopped flowing with wire removed Inverter board may be faulty. Remove the ribbon cable at J602.
If gas still flows replace the Inverter board.
e. Control & Display board could be faulty keeping the signal GAS_PWM on pin 23 always high. Replace
the Control & Display board.
5-24
SERVICE Manual 0-5475