TM-5-4310-389-14
k. Condensate Drain Switch (11). This switch causes all drains to open as long as the switch is held in the DRAIN
position.
l. Heater Condensate Switch (12). This on/off switch controls the heater for the condensate valve assembly. It is used
only when the engine is running during cold weather 32'F (00C) or below.
m. Heater On Light (13). This light indicates when the condensate heater is on.
n. Service Line Control Valve (14). This valve controls air flow to the service line outlet.
o. Low Pressure Override (15). Overrides low pressure safety switch. Used for starting.
2-3 SAFETY DEVICES.
a. Purifier Venting Bore. Located in the purifier is a vent switch which allows air to escape when the purifier cartridge is
missing. When the cartridge is in place, the vent closes, allowing air pressure to build up. This safety device
prevents the operator from delivering unpurified air. See figure 2-2.
b. Bleed Valve. This valve is used to remove air pressure from the entire system whenever maintenance is performed.
Turning clockwise opens the valve. See figure 2-3.
c. Pressure Maintaining Valve. This valve is located downstream of the purifiers and is factory set to open at 2000 psi.
Air cannot be delivered to the service outlet until the purifiers have reached an internal pressure of 2000 psi, which is
the minimum pressure for the purifiers to function properly.
d. Pressure-Relief Valves. This unit is equipped with a pressure-relief valve on each stage.
Whenever air pressure upstream of each valve exceeds the preset relief pressure, the valve will open and dump air
pressure to the atmosphere. Once the upstream pressure returns to normal, the valve will close.
e. Air Check Valve. This valve prevents air from the filled pressure vessel from backing up through the purifiers when
the compressor is not delivering air. Air flowing upstream through the purifiers can cause damage to the cartridges
and separators.
2-2
