Hypertherm HD4070 Rev.8 - Manual (Page 155)

MAINTENANCE
5-8 HD4070 Instruction Manual
1
Coolant Flow Test Procedure
1. Turn HD4070 main power OFF.
2. Remove the return coolant hose (red) from the back of the power supply for the torch you want to check.
See page 3A-4 or 3B-4 for hose location.
3. Place the return coolant hose inside a 1-gallon (4-liter) container.
4. Turn HD4070 main power ON.
5. After system initializes, press the set up button on the touch screen (Screen #3). Navigate to screen #5.
6. In a two torch system make sure the button for the torch you want to test says INSTALLED on screen #5 and
the button for the other torch says NOT INSTALLED.
7. Depress the “PUMP FAN OFF” button on the touch screen (Screen #5) and allow the pump to run for 60
seconds.
8. The gallon container should be filled within the 60 seconds. If the flow is greater than 1 gallon/minute, and the
machine is still not powering up, the flow switch is the cause of the problem. Replace flow switch. If the
container is not full, you have a flow restriction problem. Reinstall the coolant line (from step 2) and repeat step
7 at various locations in the system, (torch, Ignition console, etc.), to isolate the flow restriction.
9. To check coolant flow to the torch, remove all consumables from the torch and repeat steps 1-7.
This test checks the coolant flow from the coolant pump to the torch.
10. To check the return flow from the torch, replace all consumables and remove the return coolant hose within the
torch lead from the cathode block located in the ignition console (See figure below) and repeat step 7. This
tests the flow from the pump to the torch and out through the torch lead. If the flow is low, the problem is either
the torch or the return line in the torch lead. To isolate the problem, swap the two coolant lines in the torch lead
at the cathode block in the ignition console (See figure below). Rerun the test with the consumables removed
from the torch. If the flow is low, the problem is the return coolant line in the torch lead (the entire torch lead
assembly will need to be replaced). If the flow is good, the problem is in the torch head.
11. If the torch is suspected to have a restriction, perform the same test as in step 10, but reinstall the
consumables in the torch. Allow the coolant to run through the system for 5 minutes. This configuration
supplies coolant through the torch in the reverse direction. This creates a higher chamber pressure in the torch
and may remove particles lodged in the torch.
Cathode block
Return coolant line (Red)
Coolant lines
Ignition Console