Section 2 - Optiview Control Center Introduction - York YST Operation Manual

FORM 160.67-O1
ISSUE DATE: 4/1/2015

SeCTion 2 - opTivieW ConTrol CenTer inTroduCTion

The YORK OptiView Control Center is furnished as
standard on each chiller and provides the ultimate in
efficiency, automation, monitoring, data recording,
and chiller protection. The Control Center is a factory-
mounted, wired and tested microprocessor based con-
trol system for R134a or R22 centrifugal chillers. The
panel is configured with a diagonal color Liquid Crys-
tal Display (LCD) surrounded by "soft" keys, which
are redefined with one keystroke based on the screen
displayed at that time. This makes chiller operation
quicker and easier with a single button revealing a
wide array of information on a large, full-color illustra-
tion of the appropriate component.
The LCD display allows graphic animated display of
the chiller, chiller sub-systems and system parameters;
this allows the presentation of several operating pa-
rameters at once. The operator may view a graphical
representation of the historical operation of the chiller
as well as the present operation. A Status Bar is dis-
played at all times on all screens. It contains the Sys-
tem - Status Line and Details Line, the Control Source,
Access Level, and Time and Date.
During turbine slow roll, start up, operation and
coastdown, the system will indicate vital information
available at any time. The locations of various chiller
parameters are clearly marked and instructions for spe-
cific operations are provided on many of the screens.
The graphic display also allows information to be rep-
resented in both English (temperatures in °F and pres-
sures in PSIG) and Metric (temperatures in °C and
pressures in kPa) mode.
Security access is provided to prevent unauthorized
changes and setpoints. This is accomplished with
three different levels of access and passwords for each
level. There are screens, displayed values, program-
mable setpoints and manual controls shown that are for
Service Technician use only. They are only displayed
when logged in at SERVICE access level or higher.
These parameters affect chiller operation and should
never be modified by anyone other than a qualified
Service Technician. They are shown in this book for
reference only.
The control center is also fused to provide individual
overcurrent protected 115 VAC power for the remote
JOHNSON CONTROLS
mounted liquid pump motor starter control circuits
(supplied by others) and controls installed on the chill-
er. Numbered terminal strips for wiring such as Remote
Start/Stop, Chilled Liquid Pump Start, Condenser Liq-
uid Pump Start, and Local or Remote Cycling devices
are provided. The panel also provides field interlocks
that indicate the chiller status. These contacts include
a Remote Mode Ready-to-Start, a Cycling Shutdown,
a Safety Shutdown and a chiller Run contact. System
pressures are monitored with transmitters (4-20 mA)
and transducers (0-5 VDC). System temperatures are
monitored using thermistors and RTD's.
Setpoints can be changed from a remote location via
0-10VDC and 4-20mA, contact closures or through
serial communications. The adjustable remote reset
range [up to 20ºF (11.1ºC)] provides flexible, efficient
use of remote signal depending on reset needs. Se-
rial data interface to the Building Automation System
(BAS) is through the optional Microgateway Card,
which can be mounted inside the control Center. Inter-
faces using other industry standard protocols such as
MODBUS RTU, Johnson N2, BACnet MS/TP, LON-
MARK and ASCII are available.
The operating program is stored in non-volatile memo-
ry to eliminate chiller failure due to AC power failure/
battery discharge. Programmed setpoints are retained
in lithium battery-backed RTC memory.
Smart Freeze Point Protection will run the chiller at
36ºF (2.2ºC) leaving chilled liquid temperature elimi-
nating system trips on Low Liquid Temperature. The
program and sensors will monitor the chiller liquid and
evaporator refrigerant liquid temperatures to prevent
freeze up. Every programmable point has a pop-up
screen with the allowable ranges, so that the chiller
can not be programmed to operate outside of its design
limits.
The capacity control logic provides stable operation at
maximum efficiency at off design conditions by modu-
lating the turbine speed, compressor pre-rotation vanes
and hot gas by-pass valve.
Advanced Diagnostics and troubleshooting informa-
tion for qualified, trained Service Technicians are in-
cluded in YORK Service Manual 160.67-M3. Refer to
this manual where screen access level required = ser-
vice.
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