FORM 201.18-NM1.2
9
YORK INTERNATIONAL
SECTION 2 – RCC OPERATION
GETTING STARTED
When first powered, the message LOSS OF COMM
LINK TO AC SCREW PANEL will appear on the RCC
display. It will disappear when communications are es-
tablished in 30 seconds or less. (If backlight is on but
no display message appears, ribbon cable to display
may be on incorrectly or display is faulty.)
The PLEASE WAIT,,,,, INITIALIZING REMOTE
message will appear next. When this step is completed,
a status message will appear. Unit is then ready for
operation. See page 38 of IOM for chiller operation.
REMOTE PROGRAMMING
COOLING
LOAD
ON
SETPOINTS
LIMIT
OFF
Chilled liquid temperatures (Cooling setpoints), Daily/
Holiday Schedule (key not shown), and Load Limiting
(High Motor Current Unload) setpoints and On/Off con-
trol can be programmed from the RCC unit.
All other parameters may only be monitored from the
RCC; programming must be done at the chiller.
Full details of the above programmable features are
found near pages 126-131 of the Installation, Opera-
tion, Maintenance Manual, Form 201.18-NM1.*
* A copy of this manual is provided with each chiller.
Extra manuals can be obtained through the (York) Bal-
timore Parts Center, Baltimore MD. Ph 1-800-9321701.
SYSTEM STATUS
STATUS
The STATUS KEY will display a single message relat-
ing to the control status of the chiller or the RCC. ‘Gen-
eral’ status messages are shown below. Additional de-
tails are provided in the IOM.
General status messages can be the following:
UNIT SWITCH OFF (switch located on front panel)
DAILY SCHEDULE SHUTDOWN (daily schedule
pre-programmed function)
REMOTE CONTROLLED SHUTDOWN (chiller shut
down by manual OFF signal initiated from RCC)
NO RUN PERMISSIVE (flow switch open; no water
flow OR external device in series when flow switch is
open)
SYS SWITCH OFF (system toggle switches located
on microboard in off position)
NO COOL LOAD (indicates cooling demand rate does
not yet warrant running this system OR loading se-
quence has not progressed far enough to start this sys-
tem – often seen during the first few minutes of opera-
tion)
COMP RUNNING (compressor on)
PUMPING DOWN (pumpdown sequence at start up
or after shutdown in progress)
AR TIMER (6 minute anti-recycle timer allows time
for motor to cool sufficiently between compressor
starts)
AC TIMER (2 minute anti-coincident timer prevents
two compressors from starting at same time)
DISCH LIMITING (discharge pressure has reached the
programmable ‘discharge pressure unload’ setpoint)
SUCT LIMITING (suction temperature has reached a
point where icing may occur on the evap tubes)
CURR LIMITING (motor current has reached the pro-
grammable ‘high motor current unload’ setpoint)
EMS LIMITING (motor current has reached the motor
current unload setpoint determined by an external sig-
nal. See pg. 130 of IOM)
MANUAL OVERRIDE (manual override function
initiated at chiller keypad; setpoints at chiller will con-
trol)
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