Thermal Arc ULTIMA 150, Service Manual, Page: 46 / 64

SECTION 4: REPAIRS & REPLACEMENT 40 Manual 0-2503
H. Coolant Pressure Gauge Replacement
1. Remove the Enclosure Cover per Section 4.04.
2. Drain coolant.
3. Disconnect the Coolant Pressure Gauge Assem-
bly from the fitting at the T-Connector mounted
on the Pump Assembly.
4. Clean the old thread sealer from the threads of
the T-Connector fitting.
5. Apply a thin coating of liquid Teflon thread sealer
to the threads of the replacement Coolant Pres-
sure Gauge fitting.
6. Install the replacement Coolant Pressure Gauge
by reversing the above steps.
4.11 Front Panel Parts Replacement
This subsection describes the replacement of various parts
located near the front panel. Refer to Figure 4-18, Front
Panel Parts, for an exploded view of assemblies, or refer
to Section 5, Parts Lists, for the part number and location
of each part.
A. Gas Supply Hose Replacement (Source to
Pressure Switches)
NOTE
This procedure applies to both Plasma and Shield
Gas Supply Hoses. Note that the Shield Gas Sup-
ply Hose is identified in yellow.
1. Remove the Enclosure Cover per Section 4.04.
2. Turn Gas Regulators off.
3. Locate the Gas Supply Hose and T-Fitting, and
disconnect the Supply Hose.
4. Remove the Supply Gas Hose through the hole in
rear panel. If the hole size is too small, pinch the
sides of the plastic hose guide connector on the
rear panel and then pull it away from the panel.
5. Replace the Gas Supply Hose by reversing the
above procedure.
B. Gas Hose Replacement (Solenoid to Q.D.)
NOTE
This procedure applies to both Plasma and Shield
Gas Hoses.
1. Turn Gas Regulators off.
2. Remove the Enclosure Cover per Section 4.04.
3. Locate the Gas Hose and Solenoid. Pull the Hose
from the Solenoid Fitting while pushing the fit-
ting collar towards the fitting.
4. Remove the Hose from the Gas Fitting on the rear
of the TORCH Connector by while pushing the
collar fitting towards the fitting.
5. Replace the Gas Hose by reversing the above
steps.
C. Gas Pressure Switch Replacement
NOTE
This procedure applies to both Plasma and Shield
Gas Pressure Switches.
1. Remove the Enclosure Cover per Section 4.04.
2. Locate the Gas Pressure Switch and T-Fitting.
3. Label and remove the two wires from Gas Pres-
sure Switch.
4. Remove the Gas Pressure Switch from the T-Fit-
ting.
5. Install the replacement Gas Pressure Switch As-
sembly by reversing the above procedure.
D. Flow Meter or Solenoid Replacement
NOTE
BOTH Solenoid/Flow Meter Assemblies must be
removed through the front panel of the unit in or-
der to replace a Flow Meter or Solenoid Assembly
for EITHER gas. The following steps describe this
procedure. If detailed replacement instructions are
required for a particular assembly, refer to the ap-
propriate subsection above.
1. Turn Gas Regulators off.
2. Remove the Enclosure Cover per Section 4.04.
3. Disconnect the Plasma and Shield Gas Input
Hoses from T-Fittings.
4. Label and remove the wires connected to the
Plasma and Shield Gas Pressure Switches.
5. Remove the Plasma and Shield Gas Pressure
Switches.
6. Remove the Plasma and Shield Gas T-Fittings
from the bottom of the Plasma and Shield Gas
Flow Meters.
7. Disconnect the Plasma and Shield Gas Output
Hoses from Solenoid Fittings.
8. Label and remove the wires connected to the
Plasma and Shield Gas Solenoid Fittings.