Emerson WORLD CLASS 3000 用户手册

The valve may be flushed by rotating the socket head screw clockwise. This screw must be in the OUT 

position (counterclockwise) for normal valve operation.

On digital scroll units, discharge pressure is controlled by a motorized ball valve. During unloaded 

operation, the pressure changes during each digital cycle could cause excessive repositions with a 

pressure-operated water regulating valve. The control algorithm for the motorized ball valve uses an 

intelligent sampling rate and adjustable pressure thresholds to reduce valve repositions. The valve 

assembly consists of the brass valve, linkage and actuator.

The valve actuator operates on 24VAC power and is controlled by a 2-10VDC proportional control sig-

nal. The valve will move from fully open to fully closed in 60 seconds. At 2VDC, the valve is closed; at 

10VDC, the valve is fully open. There is a 20-second delay to position the motorized ball valve before 

starting the compressor.

The control utilizes an upper and lower pressure threshold with a 35psi (241kPa) deadband to reduce 

valve movement. If the liquid pressure is between the upper and lower threshold, the valve remains 

at the current position. If the liquid pressure exceeds the upper threshold the valve opens, and if the 

pressure falls below the lower threshold the valve closes. There are multiple adjustment bands to ease 

discharge pressure back into control range.

20 (137.9)

65 (448.2)

400 (2758)