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INTRODUCTION
The YORK Millennium Remote Control Center (RCC)
is a microprocessor-based control system capable of
remote chiller/condensing unit control. It is capable of
controlling cooling setpoints, load limit setpoint, daily/
holiday schedule, and the remote start/stop. Most unit
operational and history data is available on the RCC.
One RCC is needed for each chiller for remote moni-
toring or control.
A 40 character backlit LCD display (2 lines of 20 char-
acters) allows the operator to display system operating
parameters as well as access programmed information
already in memory. A keypad for chiller start/stop, pro-
gramming and accessing setpoints, pressures, tempera-
tures, cutouts, daily schedule, and fault information is
provided.
Microprocessor Board
The Microprocessor Board is the controller and deci-
sion maker in the control panel. This board has no in-
puts other than the RS-485 port. All communication
with the chiller will occur over the RS-485 port. All
printing will occur on the RS-232 port.
The Microprocessor Board does not contain a Real Time
Clock integrated circuit chip with an internal battery
back up. Thus all values that are modifiable on the RCC
must be stored in the chiller's battery backed RAM.
40 Character Display
The 40 Character Display is a liquid-crystal display used
for displaying system parameters and operator mes-
sages. The display has a lighted background for night
viewing as well as a special feature, which intensifies
the display for viewing in direct sunlight.
Keypad
An operator keypad allows complete control of the unit
from a remote location. The keypad offers commands
available to access displays, program setpoints, and ini-
tiate unit run commands. There are 5 divisions to the
keypad. They are outlined below.
Status – This section consists of the STATUS key and
the 40 character display. The STATUS key will be used
to display the current operating status of all systems on
the unit.
Display/Print – This section contains keys associated
with the display and printing of unit and system data.
YORK INTERNATIONAL
OPERATING CONTROLS
Following is a list of keys in the Display section of the
keypad.
• OPER DATA
• PRINT
• HISTORY
Entry – This section contains the keys used for data
entry in the various program modes. These keys are as
follows.
• ENTER
• UP Arrow
• DOWN Arrow
Setpoints – This section contains keys for program-
ming the setpoint, schedule, and load limiting the unit.
These keys are as follows.
• Cooling Setpoints
• Set Schedule/Holiday
• Load Limit
Unit – This section contains two keys, one for turning
the unit on and one for turning the unit off.
Communications
The communications between the RCC and the Middle
Market Micropanel will be limited to once every 16
seconds. The Micropanel will ignore communications
for 15 seconds after processing a valid transmission.
The Micropanel will also ignore communications for
15 seconds after power is applied.
The Chiller Micropanel will use local control, if a valid
transmission has not been received for 5 minutes from
the RCC. The remote control will be used again once a
valid new transmission has been processed. The RCC
will display an error message indicating the communi-
cations problem when such a condition occur.
FORM 150.62-NM3
1
29535A
3
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