FORM 150.60-NM3
67
YORK INTERNATIONAL
FAN CONTROL STRATEGY ABOVE 25°F AMBIENT
The chiller is equipped with 4 condenser fans; 2 per sys-
tem. The standard fan control strategy is fan cycling by
outdoor ambient temperature, with the low ambient
cut-out (chiller shut down) set at 25°F.
Above 25°F ambient, a single fan on a respective system
will turn on 4 seconds after the compressor starts. This
fan will continue to run until the compressor shuts down.
This fan is designated as Fan 2 on SYS 1 and Fan 4 on
SYS 2.
If the ambient temperature is above 45°F, a second fan
on a respective system will start after the compressor
has run for 30 seconds. This fan will continue to run until
the compressor shuts down or until the ambient tem-
perature drops to 40°F, This fan is designated as Fan 1
on SYS 1 and Fan 3 on SYS 2.
Locations of the fans and a chart showing the operation
outlined above is shown in Fig. 26.
For operation below 25°F. a Low Ambient Kit MUST be
installed. See page 73.
FIG. 26
FAN LOCATIONS
SYS. 1
SYS. 2
AMBIENT AMBIENT
FANS
FANS
ON
OFF
2 (6M)
4 (9M)
25°F
24°F
1 (5M)
3 (8M)
45°F
40°F
LD02180
The function of the compressor capacity control system
is to automatically adjust the compressor pumping ca-
pacity to balance with the cooling load at a pre-deter-
mined return water temperature and to permit the com-
pressor to start under partial load. The compressor ca-
pacity control system is actuated by means of gas pres-
sure from the discharge side of the compressor. Control
of the gas pressure to the unloader elements is the func-
tion of the compressor capacity control solenoids lo-
cated on the front handhole cover. The compressor is
loaded when the solenoid is de-energized, and unloaded
when the solenoid is energized.
Capacity is reduced by unloading one or more banks of
cylinders. Some cylinder banks are not equipped with
unloaders. This prevents the possibility of overheating,
since a definite minimum volume of cool refrigerant gas
flows through the compressor at all times during opera-
tion regardless of load conditions.
Two types of compressors are utilized. To the right is a
list of models with the model number, style of compres-
sor, number of cylinders and available standard number
of steps of unloading.
COMPRESSOR CAPACITY CONTROL
CHILLER
# OF
MODEL
COMPRESSOR
# OF
UNLOADING
YCA
TYPE
CYLINDERS
STEPS
Z88EE6
SYS 1 Z
6
5
SYS 2 Z
6
J44HE8
SYS 1 J
4
5
SYS 2 J
4
J54HE8
J55HE8
J65HE8
SYS 1 J
6
5
SYS 2 J
4
NOTE: Optional Steps of Unloading are Not Available.
Содержание YCAZ88EE8
Страница 16: ...16 YORK INTERNATIONAL WIRING DIAGRAMS LD02165 FIG 5 ELEMENTARY DIAGRAM ...
Страница 17: ...FORM 150 60 NM3 17 YORK INTERNATIONAL FIG 5 ELEMENTARY DIAGRAM Cont d LD02166 ...
Страница 20: ...20 YORK INTERNATIONAL CONNECTION DIAGRAM ELECTRICAL BOX FIG 7 CONNECTION DIAGRAM LD02171 ...
Страница 21: ...FORM 150 60 NM3 21 YORK INTERNATIONAL FIG 7 CONNECTION DIAGRAM Cont d LD02172 ...