Anticipation Control Status Messages - York eco2 YCAS0425EB Installation Operation & Maintenance

S Y S 1 P U M P I N G
Pump Down:
S Y S 2 P U M P I N G
This message indicates that both refrigerant systems
are in a pumpdown cycle. Pumpdown display messages
occur on shutdowns where the cooling load has been
met, or when a system switch is turned OFF. Note that
only one compressor could be pumping down, as shown
in the following display:
S Y S 1 P U M P I N G
S Y S 2 C O M P
See Section 1.18 (page 109) for details of pumpdown
control.
Incorrect Refrigerant Warning:
R E P R O G R A M
R E F R I G E R A N T
The Incorrect Refrigerant Warning will occur if the DIP
Switch setting for refrigerant type and the type pro-
grammed into the micro "at the factory" are not the
same. This message will be displayed until the non-
programmable "factory" programmed refrigerant type
and DIP Switch setting agree.
Power Failure Warning:
The Power Failure Warning will only be displayed on
"power restoration" after a "power loss", if manual re-
start on power failure is selected under the PROGRAM
key (Page 139). If manual restart on power failure has
been selected, the following warning message is dis-
played indefinitely on power restoration and the chiller
will not run until the UNIT Switch is cycled OFF-and-
on to restart the unit. This safety is available for users
who desire a chiller lock-out on power failure.
This is typically not a desirable feature.
! ! P O W E R
C Y C L E U N I T
When this message appears, the chiller will not run and
the Unit Switch must be cycled OFF and ON to start
the unit.
YORK INTERNATIONAL
D O W N
D O W N
D O W N
R U N N I N G
T Y P E O F
T O R U N
F A I L U R E ! !
S W I T C H
2.4 ANTICIPATION CONTROL STATUS
MESSAGES
Anticipation controls are built into the software to pre-
vent safety shutdowns by automatically overriding the
temperature controls, if system conditions approach
safety thresholds. This avoids total loss of cooling re-
sulting from a lockout by a safety control.
Anticipation controls monitor discharge pressure, mo-
tor current and suction temperature for each compres-
sor and if maximum limits are approached, the slide
valve loading of the respective compressor will be re-
duced to avoid exceeding the limit.
Displays of anticipation safety control messages and
their meanings are as follows:
Discharge Pressure Limiting:
S Y S # D S C H
S Y S # D S C H
Discharge Pressure Limiting takes effect when com-
pressor discharge pressure nears the point at which the
high pressure cutout would shut the system down. When
the above message appears, discharge pressure has ex-
ceeded the programmable threshold and the compres-
sor is being unloaded in an effort to prevent shutdown
on the high pressure cutout. The operation of this safety
is important if condenser coils become dirty, if there is
a problem with the condenser fan operation, or if ex-
treme ambient or load conditions occur (see Section
8.2 / High Discharge Pressure Unload Point [page 139]
for more details).
Compressor Motor Current Limiting:
S Y S # C U R R
S Y S # C U R R
The Motor Current Limiting message indicates that a
compressor motor current has reached a programmable,
Bas, or remote limit and the system is being unloaded
to assure that motor current does not become exces-
sively high causing a fault (see also Section 8.2 / High
Motor Current Unload Point, page 141; Section 3.5,
Motor Current Key, page 121; Section 1.10, page 105).
Suction Temperature Limiting:
S Y S # S U C T
S Y S # S U C T
The Suction Temperature Limiting message applies only
when the chiller is set for Water Cooling Mode (see
FORM 201.18-NM8
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