Thermal Arc 300GTSW Pro-Wave, Service Manual

Page: 36 / 130

pro-wave 300gtsw
5-4
June 21, 2012
H. Green AC POWER Indicator OFF; Fan Not
Operating
1. Input line disconnect switch in OFF position
a. Place input line disconnect switch to ON
position.
2. Power supply MAIN CIRCUIT BREAKER (MCB) in
OFF position
a. Place MCB to ON position.
3. Input line breaker tripped/fuses blown
a. Reset MCB; check primary supply breaker or
fuses and replace if necessary. Refer to letter
G.
4. Power supply MCB faulty
a. Check external connections to the circuit
breaker and continuity. Replace if necessary.
NOTE
Verify that for single-phase operation, the RED
input line is not connected.
5. Open conductor in input power line
a. Check continuity and replace if necessary.
6. Faulty Main Circuit Board (PCB1)
a. Check the Main Circuit Board (PCB1) supply
voltages. Refer to section 6.05, page 6-4.
Replace the Main Circuit Board (PCB1) if any
of the voltages are not present, page 6-13.
7. Faulty auxiliary transformer (T3)
a. Check auxiliary transformer (T3) primary and
secondary windings for shorts or open circuits
and replace if necessary. Refer to section 6.33,
page 6-38.
I. Red WARNING Indicator ON; No Weld Output
1. Input voltage fluctuation causing protection circuits
to activate
a. Monitor input power for spikes and high voltage
conditions. Most power utilities will monitor
and verify line voltage.
2. Easy Link not operating correctly
a. Perform the Easy Link test, section 6.04, page
6-3.
3. Thermal sensor TH1 open (thermal shutdown)
a. Allow the unit to cool for five minutes before
turning the power supply ON. If the problem
still occurs, perform the PCA Thermal Sensor
(TH1) test, section 6.31, page 6-36.
4. Warning Indicator ON when output energized.
a. Check Q1, Q2 and Q3, Q4 Section 6.26
J. Power Supply Works When in DC Output Mode,
But Not in AC Output Mode
1. Faulty IGBT modules (Q3/Q4)
a. Check IGBT modules Q3/Q4 for shorted gate
circuit or defective diodes per section 6.26,
page 6-26 and replace if necessary.
K. No Weld or Output; Fan Operating; WARNING
Indicator OFF
1. Faulty Remote Control Device
a. Connect a jumper between pins 2 and 3 of the
REMOTE 8 receptacle for contactor closure.
If amperage and voltage can be adjusted with
front panel controls, repair or replace remote
control device.
2. Faulty Front Panel PCB
a. Refer to section 6.16, page 6-18, Front Panel
Test Point Voltages.
3. Faulty Main Circuit Board (PCB1)
a. Check all connections on the Main Circuit Board
(PCB1). Perform Power Supply Voltage tests,
section 6.05, page 6-4.
b. Check PWM waveforms from front panel PCB
to Main PCB and from Main PCB to the IGBT’s.
L. Low or Maximum Weld Output With No Control
1. Faulty remote control device
a. Connect a jumper between pins 2 and 3 of the
REMOTE 8 receptacle for contactor closure.
If amperage and voltage can be adjusted with
front panel controls, repair or replace remote
control device.
2. Faulty Front Panel Circuit Board (PCB6)
a. Replace PCB6. Refer to section 6.16, page
6-18.