![background image](http://html1.mh-extra.com/html/york/ycul0045/ycul0045_installation-operation-and-maintenance_4223634080.webp)
JOHNSON CONTROLS
80
FORM 150.63-NM6 (1020)
UNIT CONTROLS
YORK
MILLENNIUM
CONTROL CENTER
The YORK MicroComputer Control Center is a micro-
processor based control system designed to provide the
entire control for the liquid chiller. The control logic
embedded in the microprocessor based control system
will provide control for the chilled liquid temperatures,
as well as sequencing, system safeties, displaying status,
and daily schedules. The MicroComputer Control Center
consists of four basic components, 1) microprocessor
board, 2) transformer, 3) display and 4) keypad. The
keypad allows programming and accessing setpoints,
pressures, temperatures, cutouts, daily schedule, options,
and fault information.
Remote cycling, demand limiting and chilled liquid
temperature reset can be accomplished by field sup
-
plied contacts.
Compressor starting/stopping and loading/unloading
decisions are performed by the Microprocessor to
maintain leaving or return chilled liquid temperature.
These decisions are a function of temperature deviation
from setpoint.
A Master ON/Off switch is available to activate or de
-
activate the unit.
INTRODUCTION
MICROPROCESSOR BOARD
The Microprocessor Board is the controller and de-
cision maker in the control panel. System inputs such
as pressure transducers and temperature sensors are
connected directly to the Microprocessor Board. The
Microprocessor Board circuitry multiplexes the analog
inputs, digitizes them, and scans them to keep a constant
watch on the chiller operating conditions. From this
information, the Microprocessor then issues commands
to the Relay Outputs to control contactors, solenoids,
etc. for Chilled Liquid Temperature Control and to react
to safety conditions.
Keypad commands are acted upon by the micro to
change setpoints, cutouts, scheduling, operating re-
quirements, and to provide displays.
The on-board power supply converts 24VAC from the
1T transformer to a +12VDC and +5VDC regulated
supply located on the Microprocessor Board. This volt-
age is used to operate integrated circuitry on the board.
The 40 character display and unit sensors are supplied
power from the microboard 5VDC supply.
24VAC is rectified and filtered to provide unregulated
+30VDC to supply the flow switch, PWM remote
temperature reset, and demand limit circuitry which is
available to be used with field supplied contacts.
00065VIP
Unit Controls
Summary of Contents for YCUL0045
Page 13: ...JOHNSON CONTROLS 13 FORM 150 63 NM6 1020 This page intentionally left blank...
Page 31: ...JOHNSON CONTROLS 31 FORM 150 63 NM6 1020 1 This page intentionally left blank...
Page 35: ...JOHNSON CONTROLS 35 FORM 150 63 NM6 1020 1 This page intentionally left blank...
Page 71: ...JOHNSON CONTROLS 71 FORM 150 63 NM6 1020 1 This page intentionally left blank...
Page 79: ...JOHNSON CONTROLS 79 FORM 150 63 NM6 1020 This page intentionally left blank...
Page 117: ...JOHNSON CONTROLS 117 FORM 150 63 NM6 1020 2 This page intentionally left blank...
Page 120: ...JOHNSON CONTROLS 120 FORM 150 63 NM6 1020 Unit Controls THIS PAGE INTENTIONALLY BLANK...
Page 139: ...JOHNSON CONTROLS 139 FORM 150 63 NM6 1020 3 This page intentionally left blank...
Page 141: ...JOHNSON CONTROLS 141 FORM 150 63 NM6 1020 4 LD08801...
Page 145: ...JOHNSON CONTROLS 145 FORM 150 63 NM6 1020 4 LD08946...
Page 147: ...JOHNSON CONTROLS 147 FORM 150 63 NM6 1020 4 LD08800...
Page 151: ...JOHNSON CONTROLS 151 FORM 150 63 NM6 1020 4 LD08776...
Page 153: ...JOHNSON CONTROLS 153 FORM 150 63 NM6 1020 4 LD08804...
Page 155: ...JOHNSON CONTROLS 155 FORM 150 63 NM6 1020 4 LD08781...
Page 157: ...JOHNSON CONTROLS 157 FORM 150 63 NM6 1020 4 This page intentionally left blank...
Page 159: ...JOHNSON CONTROLS 159 FORM 150 63 NM6 1020 4 LD08803...
Page 161: ...JOHNSON CONTROLS 161 FORM 150 63 NM6 1020 4 LD08807...
Page 163: ...JOHNSON CONTROLS 163 FORM 150 63 NM6 1020 4 LD08785...
Page 165: ...JOHNSON CONTROLS 165 FORM 150 63 NM6 1020 4 This page intentionally left blank...
Page 167: ...JOHNSON CONTROLS 167 FORM 150 63 NM6 1020 4 LD08806...