Johnson Controls YORK YVAM 0350, Operation & Maintenance Manual

Page: 48 / 162

Variable geometry diffuser screen
Figure 20: Variable geometry diffuser screen
This screen displays information pertinent to the VGD operation.
Table 29: Display only fields
Field/LED name Description
Active Stall Voltage Displays the stall detector output voltage (x.xxVdc), as received by the microboard, from the
stall board.
Active Stall Voltage Type Displays
Standard
or
Enhanced
to indicate whether the active stall voltage has enhanced
filtering applied when necessary to normalize flow noise.
Mach Number Displays the compressor calculated mach number, based on drive speed and suction
conditions.
VGD Position Displays the position of the VGD over the range of 0% (fully closed) to 100% (fully open).
Displayed as XXX until calibration procedure is performed by a qualified service technician.
VGD Command Displays the position command from the control to the VGD.
Surge Detected (LED) Illuminates for 5 seconds each time a surge is detected.
Discharge Pressure Displays the compressor discharge pressure as sensed by the transducer used for the stall
signal determination.
Condenser Pressure Displays the condenser pressure sensed by the condenser shell transducer.
Head Pressure Displays the resultant of the condenser pressure minus the evaporator pressure.
Table 30: Navigation
Button Description
Home Causes an instant return to the Home screen.
Compressor Causes an instant return to the Compressor screen.
VGD Actuator Navigates to the VGD Actuator Screen.
Compressor Navigates to the Compressor Screen.
VGD Navigates to the VGD Screen.
YVAM Control Center 48