6.
FILTER/DRIER
a.
For system cleanliness and moisture capture.
Every unit will have a filter drier factory
installed.
7.
MOISTURE INDICATOR
a.
For system charging and moisture condition.
Every unit will have a sight glass (moisture
indicator) factory installed.
8.
FLOW SAFETY THERMOSTAT (FST):
a.
Generally the cause will be low or insufficient
water flow caused by a clogged “Y” strainer or
restricted flow in the process. Resetting this
control and not determining the cause for
tripping can cause the evaporator to freeze
and rupture.
b.
Indoor chillers are normally equipped with a
Low Flow Safety temperature sensor or
thermostat that detects temperature of the
refrigerant suction. This safety will
automatically trip and requires manual
resetting before the cooling cycle will resume.
This safety can also be tripped by low ambient
conditions or during shipping.
c.
Do not reset this control unless the exact
cause for its tripping is determined.
9.
FREEZE SAFETY (FZT): (IF EQUIPPED)
a.
Indoor chillers are typically equipped with a
Freeze Safety temperature sensor that
detects low temperature of the fluid in the
system. This safety will automatically trip and
is reset automatically when the water
temperature returns to the higher sensor
setting difference.
10.
LIQUID FLOW SWITCH (LFS): (IF EQUIPPED)
a.
Refer to the LOW FLOW
SAFETY for explanation
and cautions.
b.
Outdoor units with Low
Ambient Kits are
normally equipped with
a mechanical flow
switch which monitors
the fluid entering the
evaporator. This switch is automatically reset
when the fluid flow returns to the proper flow
rate. Adjustment should not be performed
unless necessary. If adjustments are made,
ensure that the flow entering the evaporator
is greater than 3 gallons per minute per ton of
refrigeration rating of the chiller. For
example, a 2 Ton chiller will need a minimum
of 6 gpm.
11.
REFRIGERANT LOW PRESSURE SAFETY (LPS)
a)
Monitors the pressure of the refrigerant
suction line and will automatically open
when the pressure drops below the set
point and will automatically reset when
pressure is above the non-adjustable
reset setting. (See specifications for
details)
12.
REFRIGERANT HIGH PRESSURE SAFETY (HPS)
a.
Monitors the pressure of the refrigerant and
will automatically open when the pressure
rises above the sensor fixed set point. (See
specifications for details)
b.
Reset types are manual or automatic,
depending on design and system.
c.
Manual Reset - requires that a button be
pressed.
d.
Automatic Reset - automatically reset when
pressure is below the reset setting.
13.
CAPACITY CONTROLS
a.
System with multiple compressors permit the
use of capacity control using the temperature
controller system.
b.
Hot Gas Bypass (Option) - A bypass valve in
the refrigerant system that permits cooling
output capacity of the chiller to vary based on
the load of the system.
14.
LOW AMBIENT CONDITION CONTROLS
(OPTIONS)
a.
Low Ambient Conditions to 0°F Kit (Option)
b.
Temperature of the chiller’s ambient
condition is monitored and will change the
operation of the chiller fans to reduce the
possibility of cold temperatures affecting
condenser fan/compressor operation.
c.
NOTE: Low Ambient chillers typically do not
have the Low Flow Safety or a Freeze Safety.
They are equipped with a pressure controlled
fan control system which is used to operate
the fan (or Fan #2 or #3 only on multiple fan
unit chillers).
15.
WIND BAFFLES (DEPENDING ON DESIGN)
a.
Panels mounted in or on the condenser coil
section to limit/control the amount of air
entering the coils. (Option)
b.
Typically used with Low Ambient kit systems
with controls down to -20°F Kit.
16.
LOW CHILLED WATER TEMPERATURE (LOW
LCWT)
a.
Low Temperature refers to the temperature
of the fluid leaving the chiller is lower than
the temperature of the standard temperature
machine’s Leaving Chill Water Temperature
(LCWT). Glycol or some other freeze
protected fluid is required.
Figure 1 Flow Switch
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Summary of Contents for ACWC-180-EM-DR-LT-0-5
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