Printout On Fault Shutdown - York MILLENNIUM YCAR0315 Installation Operation & Maintenance

Low Motor Current Cutout / Motor Protector (Hi
Motor Winding Temp Cutout) / Mechanical High
Pressure Cutout / External Motor Overload:
S Y S # L O W
S Y S # L O W
The Low Motor Current Safety prevents a compres-
sor motor running with less current than would normally
be expected. This may result from loss of refrigerant,
contactor, or power problems, as well as from a com-
pressor that is not pumping due to a mechanical mal-
function. Motor current is monitored using 3 Current
Transformers (CTs) per motor, one on each phase.
Average motor current is monitored after 3 seconds of
compressor operation. From this time the system will
be shut down if average motor current is less than 10%
of FLA.
Compressor Motor Protection Modules and Me-
chanical High Pressure Cutouts are fitted to each
system. Both of these devices stop the compressor by
removing power from its motor contactor coils. This
causes the CTs to obviously sense a zero current draw
by the compressor motor and causes a Low Motor Cur-
rent Fault to be displayed. These devices operate as
follows :
The Motor Protection Module protects against
excessive motor winding temperature by monitoring
3 or 6 sensors built into the motor windings. If the
temperature becomes excessive, the module will
cause power to be removed from the compressor
contactors shutting down the compressor. Auto re-
start will not occur since manual reset is required. A
fault lockout will automatically occur after the micro
attempts 2 more starts with the MP contacts open.
Manual reset is accomplished by removing 115VAC
control power from the micro panel after the motor
sensors have sufficient time to cool. Details relating
to operation of the Motor Protector Module can be
found on page 18.
The Mechanical High Pressure Cutout protects
against excessive refrigerant discharge pressure and
is set to 28 bar (405 PSIG). Auto-restart will be per-
mitted after shutdown on discharge pressure, when
the pressure drops below 23 bar (230 PSIG) and the
cutout contacts close. A fault lockout will result if
safety thresholds are exceeded three times in a 90
minute period.
YORK INTERNATIONAL
C U R R / M P / H P
C U R R / M P / H P
Pumpdown Safety:
S Y S 1 P U M P D O W N
S Y S 2 P U M P D O W N
The Pumpdown Safety ensures that a compressor does
not run unless it completes a proper pumpdown. This
prevents operation of a refrigerant system which has a
leaking liquid line solenoid valve.
On shutdown, the system must pump down to the suc-
tion pressure cutout within 300 seconds, or the system
will shut down. If the system performs 3 unsuccessful
pumpdowns in a row, the system will fault and lock out.
Low Evaporator Temperature Cutout
(R-407C Only):
S Y S 1 L O W
S Y S 2 L O W
The Low Evaporator Temperature Cutout is to pro-
tect the evaporator from freeze-up with R-407C. This
safety uses the Cooler Inlet Refrigerant Temp Sen-
sors to monitor evaporator inlet refrigerant tempera-
ture on each system. These sensors are only installed
on R-407C units. If the refrigerant temperature falls
below 11.5°C (21°F) in water cooling mode, the sys-
tem will be shut down. If the refrigerant temp falls
11°C (19°F) below the leaving chilled liquid temp in
glycol cooling mode, the system will shut down. Also,
if the cooler inlet refrigerant temp sensor reads out of
range low, the system will also shut down.

2.8 PRINTOUT ON FAULT SHUTDOWN

If an optional printer is installed, the contents of History
Buffer 1 will be sent to the printer any time a fault shut-
down occurs. This will allow record keeping of indi-
vidual faults, even if they do not cause a lockout of the
system. This information may be useful to identify de-
veloping problems and troubleshooting.
The No Run Permissive fault messages will not be stored
in the History Buffer and will not cause an auto printout.
Due to extreme operating conditions
or systems where control deficiencies
are present, occasional faults may
occur with the corresponding auto-
matic printout. This is not a cause for
concern, unless oil pressure faults, liq-
uid slugging, or motor overheating
continuously occur.
FORM 150.52-NM2 (1001)
F A I L
F A I L
E V A P T E M P
E V A P T E M P
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