York YCAS0295EB, Installation Operation & Maintenance

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131 YORK INTERNATIONAL
FORM 201.19-NM7 (804)
System Switches OFF:
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. See Section 1.11, Figure 48, page 124 for the
lo ca tion of the system switches.
Anti-Recycle Timers:
The anti-recycle timer message shows the amount of
time remaining before a compressor can be called to
restart. The 300 - 600 sec. programmable timers begin
timing when a com pres sor starts, although a minimum
of two min utes must always elapse after a compressor
shuts down, be fore it may again restart. If a power failure
occurs, the anti-re cy cle timers will reset to 120 seconds
after pow er is re stored. The purpose of the timer is to
allow for motor cool ing to dissipate the heat generated
by in rush cur rent at start-up.
Anti-Coincidence Timers:
The anti-coincident timer guards against two or more
compressors starting simultaneously. This avoids ex-
ces 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.
Run Permissive Contacts OPEN:
This display indicates that an external cycling contact
and/or the fl ow switch connected to terminals 13 & 14 in
the Logic Section of the control panel is open. Whenever
the contact is open, the No Run Per mis sive message will
be displayed and the in di cat ed sys tem will not run.
System Loading Requirement:
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 sys tem
on. The lag system will display this message until the
load ing sequence is ready for the lag system to start.
If the MANUAL OVERRIDE key is pressed during a
scheduled time clock shutdown, the STATUS display
will display the MANUAL OVERRIDE message in-
dicating that the schedule is being intentionally over-
ridden. Typically MANUAL OVERRIDE is only used
in an emergency. As a result, the message is a priority
message and will override other STATUS messages.
2.3 UNIT WARNINGS
Unit Warnings are often caused by conditions which
require operator intervention to start the unit or ex treme
operating conditions. All setpoints and programmable
values should be checked, if a chiller shutdown oc-
curred, before restarting the chiller. Unit Warnings are
not logged into the HISTORY BUFFER.
Low Battery Warning
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
mi cro will re store programmed cut-
outs, setpoints, and sched ules to their
de fault values.
Once a low battery condition is detected, the only way
to run the chiller is to use the Manual Override key - see
Section 8.7.4 page 159. This al lows re pro gram ming of
setpoints, cutouts, and sched ule.
S Y S # 1 S Y S S W I T C H O F F
S Y S # 2 S Y S S W I T C H O F F
S Y S # A R T I M E R 1 0 S
S Y S # A R T I M E R 1 2 0 S
S Y S # C O M P R U N N I N G
S Y S # A C T I M E R 2 2 S
! ! 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
S Y S # N O R U N P E R M
S Y S # N O R U N P E R M
S Y S # N O C O O L L O A D
S Y S # N O C O O L L O A D
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M A N U A L
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