ADC AD-464 service manual Stack Valve Assembly, Pneumatic Valve

SECTION X

STACK VALVE ASSEMBLY

A. PNEUMATIC VALVE

The stack valve assembly consists of two (2) styles of pneumatic solenoids;

•The first type of solenoid is a 2-position/4-way/4-port single operator with a spring return. This valve has a 120 VAC coil and spring return. With no power to the coil, air goes out of the B port and the A port gets exhausted. When the coil is energized, air enters the A port and the B port gets exhausted.

•The second type of solenoid is a 2-position/4-way/4-port double operator. This valve has two (2) 120 VAC coils. With the A coil is energized, air enters the A port and the B port gets exhausted. When the B coil is energized, air exhausts the A port and the B port gets charged.

In certain positions, when a spring return piston is used, one (1) of the ports may be plugged with a plug port.

The 28 mm profile bar with 1/8" cylinder ports (Blank Station) is used as the mounting medium for the solenoid valves. Two (2) ports are drilled through the center of the Blank Station; one is for the inlet air and the other for the exhaust air. Small holes are drilled through the station at each location to tap off of these ports. There are also additional holes drilled that connect to the individual ports (A port and B port). If a position valve is not used, then a Blank Station with a gasket is placed over the holes to block any air leaks.

The coil can be tested for continuity with a standard ohm meter. With no power applied to the dryer, remove the coil plug. Place your leads across the 1 (+) and 2 (-) pin coming from the coil. The resistance measured should be approximately 700 ohms (700 Ω ). If the resistance is correct then the chances are that the coil is okay. These coils are ALL 120 VAC operated.

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