Unit Warnings - York MILLENNIUM YCAS Installation Operation & Maintenance

Compressors Running:
S Y S # C O M P
S Y S # C O M P
This message indicates that the respective compressor
is running due to demand.
System Switches OFF:
S Y S # D S C H
S Y S # D S C H
This message indicates that the system switch on the
Microprocessor Board for the respective system is in
the OFF position. A system can only run if the system
switch is in the ON position. The switch for System 1
and System 2 should normally be in the ON position for
all models. Switches for System 3 and 4 should only be
in the ON position for three and four compressor chill-
ers respectively. See Section 1.11, Figure 28 for the lo-
cation of the system switches.
Anti-Recycle Timers:
S Y S # A R T I M E R
S Y S # A R T I M E R
The anti-recycle timer message shows the amount of
time remaining before a compressor can be called to
restart. These 300 - 600 sec. timers begin timing when
a compressor starts, although a minimum of two min-
utes must always elapse after a compressor shuts down,
before it may again restart. If a power failure occurs,
the anti-recycle timers will reset to 120 seconds after
power is restored. The purpose of the timer is to allow
for motor cooling to dissipate the heat generated by in-
rush current at start-up.
Anti-Coincidence Timers:
S Y S # C O M P
S Y S # A C
The anti-coincident timer guards against two or more
compressors starting simultaneously. This avoids exces-
sive instantaneous starting currents. A minimum of 60
seconds between compressor starts is maintained even
if demand is present and the anti-recycle timers are timed
out. The display shows the time before the respective
compressor can start. This display will only appear af-
ter the anti-recycle timers have timed out.
YORK INTERNATIONAL
R U N N I N G
R U N N I N G
L I M I T I N G
L I M I T I N G
0 S
1 2 0 S
R U N N I N G
T I M E R 2 2 S
Run Permissive Contacts OPEN:
S Y S # N O
S Y S # N O
This display indicates that an external cycling contact
and/or the flow switch connected to terminals 13 & 14
in the Logic Section(s) of the control panel(s) is/are open.
Whenever the contact(s) is /are open, the No Run Per-
missive message will be displayed and the indicated sys-
tem will not run.
System Loading Requirement:
S Y S # N O
S Y S # N O
This message indicates that chilled liquid temperature is
below the point where the microprocessor will bring the
lead system on and/or that the loading sequence has not
loaded the chiller far enough to bring the lag system on.
The lag system will display this message until the load-
ing sequence is ready for the lag system to start.

2.3 UNIT WARNINGS

Unit Warnings are often caused by conditions which
require operator intervention to start the unit or extreme
operating conditions. All setpoints and programmable
values should be checked, if a chiller shutdown occurred,
before restarting the chiller. Unit Warnings are not logged
into the HISTORY BUFFER.
Low Battery Warning
! ! L O W B A T T E R Y
C H E C K P R O G / S E T P / T I M E
On power-up the microprocessor will check the RTC
(Real Time Clock) memory back-up battery to make
sure it is still operational. Provided the battery checks
out, operation will continue normally. If a check is made
and the battery has failed, the microprocessor will not
allow the chiller to run and the above Status message
will appear.
If a low battery condition exists, the micro will restore
programmed cutouts, setpoints, and schedules to their
default values.
Once a low battery condition is de-
tected, the only way to run the chiller
is to use the Manual Override key -
see Section 7.4. This allows reprogram-
ming of setpoints, cutouts, and
schedule.
FORM 201.18-NM2
R U N P E R M
R U N P E R M
C O O L L O A D
C O O L L O A D
! !
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