York YCUL0045E, Установка, эксплуатация и обслуживание

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JOHNSON CONTROLS
76
FORM 150.63-NM8 (1020)
UNIT CONTROLS
PROGRAM KEY
There are six operating parameters under the PRO-
GRAM key that are programmable. These setpoints
can be changed by pressing the PROGRAM key, and
then the ENTER/ADV key to enter Program Mode .
Continuing to press the ENTER/ADV key will display
each operating parameter. While a particular parameter
is being displayed, the UP and DOWN arrow keys can
be used to change the value. After the value is changed,
the ENTER/ADV key must be pressed to enter the data
into memory. Table 15 shows the programmable limits
and default values for each operating parameter.
Following are the displays for the programmable values
in the order they appear:
DISCHARGE PRESSURE CUTOUT is the discharge
pressure at which the system will shutdown as monitored
by the
optional
discharge transducer. This is a software
shutdown that acts as a backup for the mechanical high
pressure switch located in the refrigerant circuit. The
system can restart when the discharge pressure drops
40 PSIG (2.76 BARG) below the cutout point.
If the optional discharge pressure transducer is not
installed, this programmable safety would not apply.
It should be noted that every system has a mechanical
high pressure cutout that protects against excessive
high discharge pressure regardless of whether or not the
optional discharge pressure is installed.
The SUCTION PRESSURE CUTOUT protects the
chiller from an evaporator freeze-up. If the suction
pressure drops below the cutout point, the system will
shut down.
There are some exceptions when the
suction pressure is permitted to tem -
porarily drop below the cutout point.
Details are explained under the topic
of System Safeties.
The LOW AMBIENT TEMP CUTOUT allows the user
to select the chiller outside ambient temperature cutout
point. If the ambient falls below this point, the chiller
will shut down. Restart can occur when temperature
rises 2°F (1.11°C) above the cutout setpoint.
The programmable anti-recycle timer assures that sys-
tems do not cycle. This timer is programmable under the
PROGRAM key between 300 - 600 seconds. Whenever
possible, to reduce cycling and motor heating, the anti-
recycle timer should be adjusted as high as possible. The
programmable anti-recycle timer starts the timer when
the first compressor in a system starts. The timer begins
to count down. If all the compressors in the circuit cycle
off, a compressor within the circuit will not be permit -
ted to start until the anti-recycle timer has timed out. If
the lead system has run for less than 5 minutes, 3 times
in a row, the anti-recycle timer will be extended to 10
minutes maximum.
L O W A M B I E N T T E M P
C U T O U T = 2 5 . 0 ° F
S U C T I O N P R E S S U R E
C U T O U T = 4 4 . 0 P S I G
A N T I R E C Y C L E T I M E R
= 6 0 0 S E C
d
D I S C H A R G E P R E S S U R E
C U T O U T = 3 9 5 P S I G
TABLE 15 – COOLING SETPOINTS PROGRAMMABLE LIMITS AND DEFAULTS
SETPOINT VALUE LOW LIMIT HIGH LIMIT DEFAULT
Discharge Air Temp. Setpoint
45.0 °F 70.0°F 44.0°F
7.2°C 21.1°C 12.7°C
Discharge Air Temp. Range
3.0°F 10.0°F 5.0°F
1.7°C 5.6°C 2.8°C
Suction Pressure Setpoints
60 PSIG 90 PSIG 70 PSIG
4.14 BARS 6.21 BARS 4.83 BARS
Suction Pressure Range
2 PSIG 10 PSIG 3 PSIG
.13 BARS .69 BARS .20 BARS
Max EMS - PWM Remote Temp. Reset
2°F 40°F 20°F
1°C 22°C 11°C