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166

YORK INTERNATIONAL

FORM 201.19-NM5 (804)

The Pilot Solenoid is also used as a low su per heat safety
de vice when EEV is selected as the ex pan sion valve
type, for YCAL units only. While the sys tem is run ning
and not in a pumpdown mode the Pilot So le noid will
close if the suction su per heat falls be low 4.0º F. The
Pilot Solenoid will open again when the su per heat ris es
above 7.0º F. This safe ty de vice is ignored for the fi rst
30 sec onds of sys tem run time. If the Pilot Solenoid is
closed 10 times in 2 min utes on the safe ty de vice, the
low su per heat safe ty will be trig gered.

LOW SUPERHEAT CUTOUT SAFETY

The Low Superheat Cutout is to protect the com pres sors
from liquid fl oodback due to low suc tion su per heat. This
safety is only active when EEV is selected as the expan-
sion valve type. This safe ty is ignored for the fi rst 30
seconds of system run time.

This safety can be triggered by two events. The fi rst is
when the suction superheat is less than 0.5º F (1.1ºC)
for 3 seconds. The second, only applies to YCAL units,
is when the Pilot Solenoid is closed 10 times in 2 min-
utes due to low superheat. Fol low ing are the safety fault
mes sag es for all sys tems:

SENSOR FAILURE CUTOUT SAFETY

The Sensor Failure Cutout is to prevent the EEV from
running when the sensors measuring su per heat are not
functioning properly. This safety is only active when
EEV is selected as the expansion valve type. This safe ty
is ignored for the fi rst 15 seconds of system run time.

This safety will shutdown a system if either suc tion tem-
per a ture or suction pressure sensors read out of range
high or low. This condition must be present for 3 sec onds
to cause a system shut down. This safety will lock out a
system the fi rst time and will not allow automatic restart-
ing. Fol low ing are the messages for all systems:

OPERATING DATA DISPLAYS

The following display relating to EEV operation is avail-
able under each systems Data Key: EEV Output% and
Suction Superheat.

HISTORY DATA DISPLAYS

The following display relating to EEV operation is avail-
able under each systems Data Key: EEV Output% and
Suction Superheat.

Micro Panel Contents

S Y S 1 L O W S U P E R H E A T

S Y S 2 L O W S U P E R H E A T

S Y S 1 S E N S O R F A I L U R E

S Y S 2 S E N S O R F A I L U R E

S Y S X E E V = X X X . X %

S U C T S H E A T = X X X . X º F

S Y S X E E V = X X X . X %

S U C T S H E A T = X X X . X º F

OPERATING DATA PRINTOUT

Pressing the PRINT key and then the OPER DATA key
allows the operator to obtain a printout of cur rent sys tem
operating parameters. When the OPER DATA key is
pressed, a snapshot will be taken of system operating
conditions and panel programming selections. This data
will be tem po rari ly stored in memory and transmission
of this data will begin to the printer. The following items
are added to the standard operational data print out when
EEV is selected:

SYSTEM 1 DATA

COMPRESSORS STATUS

OFF

RUN TIME

0- 0- 0- 0 D-H-M-S

MOTOR CURRENT 0 AMPS 0 %FLA

SUCTION PRESSURE

125 PSIG

DISCHARGE PRESSURE

131 PSIG

OIL PRESSURE

130 PSIG