Hypertherm HT400 Air Injected Water Muffler System - Manual (Page 23)

OPERATION & MAINTENANCE
Page 3-2 Air Injected Water Muffler System
Instruction Manual
OPERATION
The Air Injection Water Muffler System will start automatically with the initiation of the
start signal to the plasma cutting torch. The pump contactor coil and air solenoid
valve are energized simultaneously by a 120 VAC signal routed through the ON/OFF/
SET switch in the air control box from the power supply.
• When the switch is in the ON position, the 120 VAC signal will be supplied to the
pump contactor and air solenoid valve when the power supply main contactor is
activated.
• When the switch is in the SET position, the 120 VAC signal will be supplied to the
pump contactor and air solenoid valve. In this position, the air pressure values
are set. The power supply main contactor is not activated at this time.
• When the switch is in the OFF position, the water muffler system is disabled.
The operating procedures and requirements for above and underwater cutting are as
follows:
Daily Setup and Operation
1. Apply primary power to the power supply.
2. Apply shop air to the air control box. Inside the box, ensure the ON/OFF/SET
switch is to OFF.
3. Depress the green POWER ON switch to turn on the power supply.
4. Inside the air control box, position the ON/OFF/SET switch to SET. With water
and air flowing, check the pressure gauge for 17 psig @ 10 scfm (1.2 bar @ 283
l/m) for above- water cutting or 30 psig @ 20 scfm (2.0 bar @ 566 l/m) for
underwater cutting. Adjust the pressure regulator, if required.
5. Check for an even flow of water around the torch and for leaks around all
connections. Tighten connections as necessary. The water pump should deliver
approximately 18 to 20 gallons per minute.
6. Recheck the air pressure as performed in step 4, if required.
7. Position the ON/OFF/SET switch to ON. The system is now operational.
Above-Water Cutting
At the water table, ensure the water level is maintained at or slightly above the
bottom of the workpiece. Due to water muffler system pressure drops, the pressure
setting of 17 psig (1.2 bar) may be insufficient to supply the 10 scfm (283 l/m)
flowrate. If this is the case, increase the pressure until the proper flowrate has been
achieved.
If initial height sensing (IHS) is not used, manual torch positioning will be necessary.