Ultra-cut 300 xt – Tweco 300 XT Ultra-Cut Plasma Cutting System User Manual

Page 149

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ULTRA-CUT 300 XT

Manual 0�5�7�

PPENDIX

��3

section (INV 1, INV 1B, etc.).  100 unit will only have ribbon cables in J31 & J3�; a �00 will have J31�J33 filled

with the others empty. 300 will have J3� missing with the others filled.

Other boards in the system include the

System Bias Supply, the Relay & Interface PCB, Display PCB, Pilot PCB

and AC Suppression PCB. The CCM has � boards, the I/O (input/output) and the CPU (central processing unit)

board. The CE units will also have one or more EMI Filter boards on the input power.
System Bias supply PCB is powered from the 3 phase C input and works from about 150V to over 600V covering

all the normal voltage ranges. It can operate from � phases (single phase) so it still provides bias power and can

report a fault if a phase is missing. The supply’s output is �� VDC which powers the Relay board, the Display, the

Pilot board and the � boards in the CCM. System Bias also contains circuits to detect missing phase and determine

if the C voltage is within the correct range, not too high or too low. It also signals to the CCM what voltage the

unit is configured for. The System Bias supply PCB includes a relay, K1, which only applies voltage to uxiliary

transformer, T1, primary when the input voltage is in the correct range.

The

Relay and Interface PCB ccepts and distributed the output of the ux Transformer. It has relay to control

the pump, fans, input contactors, the rc Starter and the Inrush relays.  circuit on the Relay board accepts input

from the Work current sensor, HCT1, and Pilot current sensor (on the Pilot PCB) and sends the Enable signal to the

Pilot boards IGBT switches via the J3 to J�� ribbon cable. Other inputs on the Relay board include those from the

Negative Temperature Coefficient (NTC) ambient and coolant temperature sensors. Coolant tank level switch and

coolant flow switch, which determines if the flow is above the required minimum rate, also send signals to the Relay

Board. Ultra�Cut units include a flow sensor whose output to the Relay Board is a series of pulses whose frequency

indicates the flow rate and can detect the presence of gas bubbles in the coolant. ll these signals pass to the CCM

via a �0 conductor ribbon cable going to the CCM I/O board.

The

Display Board Has LEDs for C, TEMP, GS & DC. It also has a � digit 7 segment display for status and fault

information. C LED indicates the input contactors to the inverters have been commanded to close, but does not

mean they are closed. TEMP means one or more inverters or the coolant has exceeded the allowed temperature.

GS means gas is flowing and coolant flow is OK. DC means the inverters output voltage is above 60 VDC.

The first digit of the 7 segment display shows the letter, “C”; “E”; “L” or is blank. During the initial power up se�

quence the letter “C” followed by the other 3 digits, indicates the CCM code revision. Status or Fault codes which

may occur during the power up sequence or any time thereafter are preceded by letters “E” for an active fault or

“L” for a “latched” or “last” fault that stopped the process but is no longer active. When there is no Fault or active

Status code, the output current setting is displayed with the first digit blank. If the system is an Ultra�Cut XT using

the uto Gas Control, DFC 3000, the display will show “0” until a process has been loaded. If there is a fault or

other status showing the display will alternate between the current setting and the fault.

The

Pilot PCB contains a pair of parallel IGBT transistors working as an electronic switch to connect and disconnect

the torch tip from the 1st inverter section.

When the pilot electronic switch is closed and the pilot is ignited by the rc Starter, current from the 1st section

flows between electrode and tip. Then as transfer begins, a small current from the �nd inverter flows from elec�

trode to work. When transfer is detected the pilot switch is opened and current from the 1st section is free to flow

to the work through the diode which is also on the Pilot board. The Pilot PCB also contains a pilot current sensor

to detect and measure the level of pilot current. dditional resistor/capacitor (RC) circuits on the pilot PCB assist

and stabilize the pilot and transferred arcs.

Art # 12301

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