Hypertherm HD3070 Plasma Arc Cutting System w/ Automatic Gas Console - Manual (Page 86)

3-38 HD3070 with Automatic Gas Console Instruction Manual
16
INSTALLATION
Torch Coolant Requirements
The power supply is shipped without any coolant in the tank. A standard mixture of propylene glycol (30%),
deionized water (69.9%) and benzotriazole (0.1%) is recommended. This mixture resists freezing to +10° F (-12° C)
and contains a corrosion inhibitor (benzotriazole) to protect copper surfaces in the coolant loop. This mixture is
available in 1-gallon containers by ordering 028872. 100% propylene glycol is available by ordering 028873.
Freezing torch coolant can result in a cracked torch head, leads, or other damage to the torch cooling system. For
operating temperatures colder than +10° F (-12° C), the percentage of propylene glycol must be increased. See
Figure 3-32.
Coolant will become more conductive the longer it is in service. If the conductivity of the coolant becomes too high,
the coolant may conduct torch voltage, resulting in the torch misfiring and can be a shock hazard. Check coolant
conductivity whenever the cooling system is serviced.
Conductivity of new coolant mixture should not exceed 10 µ Siemens/cm at 77° F (25° C). Every 6 months, flush
the power supply of its torch coolant and replace with new coolant.
Observe the warning and caution below. Refer to the Material Safety Data Sheets in Appendix C for data on
safety, handling, storage and disposal of propylene glycol and benzotriazole.
Caution: Always use propylene glycol in the coolant mixture. Do not use antifreeze in
place of propylene glycol. Antifreeze contains corrosion inhibitors which will
damage the torch coolant system.
Always use purified water in the coolant mixture in order to prevent corrosion
in the torch coolant system. The hardness of purified water should be between
0.206 and 8.5 ppm. If using a conductivity meter to measure water purity, the
recommended level is between 0.5 and 18 µ Siemens/cm at 77° F (25° C).
WARNING
Propylene glycol and benzotriazole are irritating to skin and eyes, and harmful or fatal if swallowed. Upon
contact, flush skin or eyes with water. If swallowed drink water and call a physician immediately. Do not
induce vomiting.