York YR manual Optiview Control Center

Guide Specifications

FORM 160.81-EG1

operated isolation valves located at the inlet to the oil separator and outlet of the condenser (isolation valves optional). Additional valves shall be provided to facili- tate removal of refrigerant charge from the system.

OPTIVIEW CONTROL CENTER

General – The chiller shall be controlled by a stand-alone microprocessor based control center. The chiller control panel shall provide control of chiller operation and moni- toring of chiller sensors, actuators, relays and switches.

Control Panel – The control panel shall include a 10.4- in. diagonal color liquid crystal display (LCD) surrounded by "soft " keys which are redefined based on the screen displayed at that time. This shall be mounted in the middle of a keypad interface and installed in a locked enclosure. The screen shall detail all operations and parameters, using a graphical representation of the chiller and its ma- jor components. Panel verbiage shall be available in other languages as an option with English always available. Data shall be displayed in either English or Metric units. Smart Freeze Point Protection shall run the chiller at 36°F (2.22°C) leaving chilled water temperature, and not have nuisance trips on low water temperature. The sophisti- cated program and sensor shall monitor the chiller water temperature to prevent freeze-up. When needed, Hot Gas Bypass is available as an option. The panel shall display countdown timer messages so the operator knows when functions are starting and stopping. Every programmable point shall have a pop-up screen with the allowable ranges, so that the chiller can not be programmed to operate outside of its design limits.

The control panel shall be provided with a thermal ice storage control mode to enhance system performance during ice building operation. In the thermal storage con- trol mode, the chiller shall stay at 100% load until the setpoint shutdown temperature is reached. To add greater operating flexibility and eliminate unnecessary chiller cycling, two different Low Water (Liquid) Tem- perature Restart Thresholds shall be programmable, one for the ice mode and one for the standard cooling mode. The chiller shall have the capability to remain in the standard control mode for temperatures between 20 to 70°F (-6.7 to 21.1°C) for applications involving a pro- cess cooling duty that requires leaving chilled liquid tem- perature setpoint control.

The chiller control panel shall also provide:

1.System operating information including:

a.Return and leaving chilled water temperature

b.Return and leaving condenser water temp.

c.Evaporator and condenser saturation temp.

d. Oil pressure at compressor and oil filter differential

e. Percent motor current

f.Evaporator and condenser saturation temp.

g.Compressor discharge temperature

h.Percent slide valve position

i.Operating hours

j.Number of unit starts

2.Digital programming of setpoints through the uni- versal keypad including:

a.Leaving chilled water temperature

b.Percent current limit

c.Pull-down demand limiting

d.Six-week schedule for starting and stopping the chiller, pumps and tower

e.Remote reset temperature range

3.Status messages indicating:

a.System ready to start

b.System running

c.System lockout

d.System safety shutdown-manual restart

e.System cycling shutdown-auto restart

f.System startup

g.Start inhibit

4.The text displayed within the system status and system details field shall be displayed as a color coded message to indicate severity: red for safety fault, orange for cycling faults, yellow for warnings, and green for normal messages.

5.Safety shutdowns enunciated through the display and the status bar, and consist of system status, system details, day, time, cause of shutdown, and type of restart required. Safety shutdowns shall include:

a.Evaporator - low pressure

b.Evaporator - low pressure - smart freeze

c.Evaporator - transducer or leaving liquid probe

d.Evaporator - transducer or temperature sensor

e.Condenser - high pressure contacts open

f.Condenser - high pressure

g.Condenser - pressure transducer out of range

h.Auxiliary safety - contacts closed

i.Discharge - high temperature

j.Discharge - low temperature

k.Oil - low differential pressure

l.Oil or condenser transducer error

m.Oil - clogged filter

38 YORK INTERNATIONAL