FORM 150.44-NM4
31
YORK INTERNATIONAL
display this message until the loading sequence is ready
for the lag system to start (TEMPERATURE DEMAND
in the OPER DATA displays must be 5 or above be-
fore cooling load is established for the lag system to
run).
The COMP RUNNING message indicates that the re-
spective compressor is running due to demand.
The anti-recycle timer message shows the amount of
time left on the respective anti-recycle timer. This mes-
sage is displayed when demand requires the respec-
tive system to start but is being held off due to the timer.
The anti-coincident timer is a software feature that
guards against 2 compressors starting simultaneously.
This assures instantaneous starting current does not
become excessively high due to simultaneous starts.
The micro limits the time between compressor starts to
1 minute regardless of demand of the anti-recycle timer
being timed out. The time shown on the anti-coincident
timer is the time left on the timer before the respective
system will start. Demand must be present for the mes-
sage to be displayed and will only appear when the
anti-recycle timer has timed out.
The Suction Pressure Limiting message indicates a
system is being unloaded by the micro even though
demand requires loading. This safety assures that re-
frigerant returning to the compressor provides proper
motor cooling, assuring that motor life is not compro-
mised. This safety will only activate when the chilled
liquid temperature is excessively high. Unloading will
take place when suction pressure exceeds the user
programmable threshold of 80-105 PSIG. Reloading
will take place when suction pressure drops to 10 PSIG
below the safety threshold.
Discharge Pressure Limiting takes affect when dis-
charge pressure nears the point at which the high pres-
sure cut-out will shut down causing total loss of cool-
ing. When this message appears, discharge pressure
has exceeded the user programmable threshold and
the micro is unloading the affected system to prevent
shutdown on a manual high pressure cut-out. Reload-
ing will take place when discharge pressure has
dropped 60 PSIG below the threshold.
Optional discharge pressure transducers must be in-
stalled for this feature to operate. This is accomplished
by adding the Discharge Pressure Readout option.
If the MANUAL OVERRIDE key is pressed, the STA-
TUS display will display the message shown above.
This will indicate that the Daily Schedule is being ig-
nored and the chiller will start-up when water tempera-
ture allows, UNIT Switch permits, and SYSTEM
Switches permit.
This is a priority message and cannot be overridden
by anti-recycle messages, fault messages, etc. when
in the STATUS Display mode. Therefore, do not ex-
pect to see any other STATUS messages when in the
MANUAL OVERRIDE mode. MANUAL OVERRIDE is
to only be used in emergencies or for servicing.
FAULT STATUS MESSAGES
Fourteen possible fault messages may appear when
the STATUS key is pressed. Whenever a fault mes-
sage appears, the safety thresholds on the chiller have
been exceeded and the entire chiller or a single sys-
tem will be shut down and locked out. A detailed expla-
nation of the shutdown thresholds and associated in-
formation related to each fault is covered in the SYS-
TEM SAFETIES section (Page 50).
Chiller shutdown faults will shut the entire chiller down
and lock it out, while system shutdown faults will only
shut down and lock out the affected system (compres-
sor).
A list of the fault messages are shown on the next page:
S Y S # 1
C O M P
R U N N I N G
S Y S # 2
C O M P
R U N N I N G
S Y S # 1
A R
T M R
X X X
S
S Y S # 2
A R
T M R
X X X
S
S Y S # 1
A C
T M R
X X
S
S Y S # 2
A C
T M R
X X
S
S Y S # 1
S U C T
L I M I T I N G
S Y S # 2
S U C T
L I M I T I N G
S Y S # 1
D S C H
L I M I T I N G
S Y S # 2
D S C H
L I M I T I N G
M A N U A L
O V E R R I D E