Thermal Arc 300GTSW Pro-Wave, Service Manual

Page: 60 / 130

pro-wave 300gtsw
6-22
June 21, 2012
6.20 Current Transformer Test Procedure
1. Disconnect connector CN1 from the Main Circuit
Board (PCB1).
2. With an Ohmmeter set the Rx10 scale, measure
between the pins on the CN1 plug as follows:
Pin 4 (YELLOW) and Pin 1 (BROWN) > 120KOhms
Pin 4 (YELLOW) and Pin 2 (RED) @ 20KOhms
6.21 Current Transformer Replacement
Procedure
Refer to figure 6-19.
to remove the Current transformer (Ct):
1. Remove the Output Inductor Assembly per section
6.37on page 6-42.
2. Remove hardware from Output Bus Bar/IGBT
Inverter (Q3/Q4) Bus Bar junction.
3. Remove the bolt and associated hardware from the
inside of the POSITIVE (+) OUTPUT TERMINAL.
4. Remove the connector with the RED/YELLOW/
ORANGE/BROWN twisted wiring harness from
the CT.
5. Remove the Output Bus Bar/CT.
6. At the end removed from the POSITIVE (+)
OUTPUT TERMINAL, bend the Output Bus Bar
sufficiently to allow the CT to slide off the end of
the bus bar.
to replace the Current transformer:
1. Slide the new CT onto the Output Bus Bar, in the
same orientation as the one removed.
2. Return the end of the Output Bus Bar to a right
angle (90° bend).
The next step makes it much easier to complete the
replacement due to interference with the Coupling Coil.
3. On IGBT Inverter Q3/Q4, remove the two screws
securing the bus bar that was attached to the
Output Bus Bar/CT Assembly.
4. Replace the hardware to joint the bus bar removed
from Q3/Q4 and the Output Bus Bar/CT Assembly.
Finger tighten.
5. Replace the bus bar onto Q3/Q4. Securing the
two screws through the bus bar into Q3/Q4 may
require using a screwdriver at an angle, or a right-
angle screwdriver if available.
6. Reverse the remaining removal steps.
IGBT Inverter Q3 Junction Hardware
Bolt, Positive (+) Output
Current Transformer Output Bus Bar
Art # A-06124
Figure 6-19: Current transformer and output bus bar