ESAB 100i Service Manual page 103

a. If the pump motor is not getting 230 VAC, measure for 24 VAC on the coil of MC3. If present and the relay
contacts aren't closed the relay is defective. Note, the coil is rectified so you won't measure continuity of
even a good coil.
b. If 24 VAC is not on the MC3 coil check for D27 on the relay board being ON. If it's on the Relay board should
be providing the 24 VAC so if it's not the Relay board may be defective. Measure for 24 VAC at J9-6 to J9-12
on the Relay board. If 24 VAC is present and D27 is on, the Relay board or the wire harness is defective.
c. If D27 is not on, measure on the CCM I/O board between TP3 and the common at TP1. It should be low,
near zero volts. If not the CCM is probably defective. Jumper TP3 (I/O board) to TP1. If the pump comes
on now replace the CCM.
d. If jumping TP3 to TP1 does not turn the fans on then the Relay board or the 40 pin ribbon cable pin 13 is at fault.
CCM I/O PCB
To test Pump relay jump TP3 to TP1.
J4-13
+24
Coolant flows but flow is less than the required minimum:
Test and adjust the pump/bypass valve:
This test measures the "dead head" or blocked flow pressure at the rear panel coolant supply fitting. Perform
this test only after the coolant system is fully primed, that is after the coolant is circulated throughout the system
and is mostly free of bubbles. It requires a pressure gauge with #6 JIC fitting.
The gauge needs to be able to read at least 173 PSI. Remove the coolant supply hose and connect the pressure
gauge in its place.
NOTE!
Do not put the gauge in-line and attempt to pinch off the hose to block the flow. It is very difficult to
totally block the flow and failure to do so will result in incorrect setting of the bypass.
Turn the on the unit. You will have 4 minutes to perform the test/adjustment before the system times out with
a coolant flow fault. If that happens recycling the power gives you another 4 minutes.
1. The pressure on the gauge should be close to 173 (170-175) PSI. If it is the pump and the bypass are OK.
2. If the pressure is less than 173 PSI adjust the bypass screw clockwise to raise the pressure. If you can
change the pressure with the bypass screw but cannot reach 173 PSI it is likely the pump is worn out or
damaged. If the pressure does not change using the bypass screw it is likely the bypass is defective.
3. If the pressure is above 173 reduce the pressure by adjusting the bypass valve screw counter clockwise.
Coolant flow test:
Manual 0560956456
TP3
TP1
Relay PCB
J8
1
24 VAC
2
3
4
5
K5 6
1 7
2 8
9
D27
4 10
11
3 12
5 13
14
15
Coolant Pump Control
16
APPENDIX
iSERIES 100 /200 /300 /400
230 VAC from T1
J13
MC3A
(66)
(65B)
MC3B
CHASSIS GND
(67)
(64B)
(162)
MC3
SA4
Coolant pump Control
ARC_SUPPRESSOR
(163)
J16
M1
1
2
3
Torch Coolant Pump
Art # 12313
A-83