74 - "Th""1" On Displays (B) (C) Of The Power Source And (F) (M) Of The Gas Console. High; Temperature Of The Igbt Group On Pilot Arc Board (58) Or Of The Transformer (27); 75 - "H2O" On Display (B) Of The Power Source And Display (F) Of The Gas Console. Insufficient Flow Of The Cooling Liquid; 76 - "H2O""N.c." On Displays (B) (C) Of The Power Source And (F) (M) Of The Gas Console. Cooling Unit Not Connected - Cebora PLASMA PROF 164 HQC Service Manual

CEBORA S.p.A.
3.4.13 - 74 - "TH""1" on displays (B) (C) of the Power Source and (F) (M) of the Gas
Console. High temperature of the igbt group on pilot arc board (58) or of the
transformer (27).
With this alarm we recommend not shutting off the Power Source, to keep the fan running
and thus allow rapid cooling. Normal operation is restored automatically as soon as the
temperature returns within the allowed limits.
− Make sure the fan (20) is operating correctly.
− Make sure the air is flowing properly and that there no dust or obstacles are blocking the
cooling ducts inside the Power Source.
− Make sure that the working conditions comply with the specified values, especially observing
the "duty cycle".
− Check the wiring between J8 pilot arc board (58), and the thermostat on the dissipater of the
pilot arc board (58) igbt.
− Make sure the thermostat mounted on the dissipater of pilot arc board (58) is properly
mounted and operating; its contact must be closed at ambient temperature.
− Check the wiring between J7 torch board (42) and J19 control board (38).
− With Power Source off, temporarily disconnect J7 on pilot arc board (58). Power up the
Power Source again and check on the patch connector removed from J7 voltage = 27 Vac
(alarm condition). If incorrect, replace control board (38).
− Replace the control board (38).
3.4.14 - 75 - "H2O" on display (B) of the Power Source and display (F) of the Gas Console.
Insufficient flow of the cooling liquid.
The flow of liquid in the cooling circuit is detected by the flow meter (12).
To analyze the corresponding circuit, see FLOW METER (12) TEST, par. 3.3.11.
3.4.15 - 76 - "H2O""n.c." on displays (B) (C) of the Power Source and (F) (M) of the Gas
Console. Cooling unit not connected.
The "cooling unit connected" signal is provided by a jumper between terminals 2 and 4 of the
patch connector inserted in J20 of control board (38). To analyze the corresponding circuit, see
COOLING UNIT ENABLE TEST, par. 3.3.11.

3.4.16 - 78 - Gas pressure low.

3.4.17 - 79 - Gas pressure high.

These alarms indicate that the pressure in a gas circuit is below the minimum or above the
maximum allowed for the operation.
The signals are provided by the 5 pressure detectors in the Gas Console (PT1...PT5 see fig.
2.6.1), whose signals are analyzed from the panel board (20).
The low pressure alarm check is active only during cutting, and affects only the two CUT
circuits (PT2 and PT4). The alarm threshold is set via software to approximately 60% of the
correct value.
The high pressure alarm test is active for all 5 channels, while cutting, while the system is
emptying upon system start-up, during the "Gas Seal" test. The high pressure alarm threshold is
set via software at approximately 9 Bar, corresponding to the approximately 9 Vdc detectable on
connectors J1, J2, J3, J4 and J5 of panel board (20).
During discharge, the check waits for the pressure to reach zero in all circuits before
beginning to fill the circuits. If one of the pressure switches does not provide the signal
corresponding to a pressure of zero (0 Vdc on connectors J1, J2, J3, J4 and J5 of panel board
(20), the test stops operation due to error (79).
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9/8/2006