Capacity Controls Screen - Johnson Controls YORK OM Titan Operating Instructions Manual

FORM 160.72-O1 (810)
figure 14 -

CAPACITy CONTROLS SCREEN

overvieW
This screen displays the present state of the capacity
controls for the system. Each section of the display
controls the PRV or HGBV according to the setpoints
configured within that section. The output to the PRV
or HGBV will follow the flow chart lines on this dis-
play. Each selector switch line is animated and will
toggle between the connecting points to indicate the
control point for that switch. For a more complete dis-
cussion of the sequence for this display, see the Capac-
ity Control Section.
displaY onlY
evaporator setpoint – override limit
Pressure at which the PRV's will begin to close in order
to prevent the chiller from tripping off or low evapora-
tor pressure.
evaporator pressure – override limit
Displays the present refrigerant press evaporator.
Condenser setpoint – override limit
Pressure at which the PRV's will begin to close to pre-
vent the chiller from tripping off or high condenser
pressure.
JOHNSON CONTROLS
CapaCiTY ConTrols sCreen
Condenser pressure – override limit
Displays the present refrigerant pressure in the con-
denser.
Current limit setpoint – override limit
Displays the present demand limit setpoint value in use.
% full load amps – override limit
Displays the motor current as a percentage of the Full
Load Amps (FLA) value. For the Electro-Mechanical
Starter this is the data returned by the CM-2 board.
prv ramp
Displays the ramp rate for the PRV during the startup of
the chiller. The system status will display CONTROLS
RAMPING when this rate is in effect.
high head Min. vane – anti-surge
Displays the minimum pre-rotation vane position setpoint
required for stable operation at high head conditions.
low head Min. vane – anti-surge
Displays the minimum pre-rotation vane position
setpoint required for stable operation at low head con-
ditions.
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