United CoolAir VariCool VAV, Инструкция по установке, эксплуатации и обслуживанию

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Installation, Operation and Maintenance Manual
VariCool
®
VAV
21 Subject to change without notice. 10.20-IM (0818)
Adjustments should be made in small increments,
allowing the system to stabilize after each turn�
5�
Vary the evaporator load to test at various conditions
that the suction pressure does not fall below the set
point (104 psig for R-410a)
6� Replace the seal cap on the hot gas bypass valve
Sequence Of Operation Cooling - - Air-Cooled
The following sequence is based on the unit being controlled
by a suitable room thermostat If another control type is being
utilized, reference the instructions for that device
a� Raise thermostat set point to highest level
b� Set System switch to “OFF” position
c� Set Fan switch to the “AUTO” position
d� Moving the Fan switch to the “ON” position should
cause the evaporator blower motor to run Moving the
Fan switch back to “AUTO” should stop the blower
e� Move the System switch to the “COOL” position
Slowly lower the thermostat setting to call for cooling
The evaporator blower should start (assuming the
Fan switch is set to “AUTO”) and the System lead
compressor should start The condenser blower on an
air-cooled unit should start when the compressor is
activated
f� On those units with multiple compressors, if the
thermostat set point continues to be lowered, the
second compressor should then start Please note that
there may be a time delay between stages
g� Set room thermostat at desired space temperature and
the Fan switch to “AUTO” or “ON” The unit will cycle as
required to maintain conditions
Cooling - - Water-Cooled
A water-cooled unit sequence will be the same as above,
except that air-cooled blower will be replaced by a pump or
valve being activated for water flow through the condenser.
Cooling - - Chilled Water
Chilled water unit sequence is the same as the above,
except that the compressor and condenser blower activation
is replaced by the chilled water valve function
Heating (Other Than Heat Pump)
The following sequence is based on the unit being controlled
by a suitable room thermostat If another control type is being
utilized, reference the instructions for that device
a� Lower thermostat set point to lowest level
b�
Set System switch to “OFF” position
c� Set Fan switch to the “AUTO” position
d� Moving the Fan switch to the “ON” position should
cause the evaporator blower motor to run Moving the
Fan switch back to “AUTO” should stop the blower
e� Move the System switch to the “HEAT” position Slowly
raise the thermostat setting to call for heating The
evaporator blower should start (assuming the Fan
switch is set to “AUTO”) and the heat type (electric, hot
water or steam) should start
f�
On those units with multiple heat stages, if the
thermostat set point continues to be raised, the
additional heat stages should then start Please note
that there may be a time delay between stages
g� Set room thermostat at desired space temperature and
the Fan switch to “AUTO” or “ON” The unit will cycle as
required to maintain conditions
Heating (Heat Pump, Water Source)
The following sequence is based on the unit being controlled
by a suitable heat pump room thermostat If another control
type is being utilized, reference the instructions for that
device
a� Lower thermostat set point to lowest level
b� Set System switch to “OFF” position
c� Set Fan switch to the “AUTO” position
d� Moving the Fan switch to the “ON” position should
cause the evaporator blower motor to run Moving the
Fan switch back to “AUTO” should stop the blower
e� Move the System switch to the “HEAT” position
Slowly raise the thermostat setting to call for heating
The evaporator blower should start (assuming the
Fan switch is set to “AUTO”) and the System lead
compressor should start A pump or valve should also
be activated for water flow through the condenser.
f� On those units with multiple compressors, if the
thermostat set point continues to be raised, the
additional heat stages should then start Please note
that there may be a time delay between stages
g� Set room thermostat at desired space temperature and
the Fan switch to “AUTO” or “ON” The unit will cycle as
required to maintain conditions