The Right Fit For Comfort
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10
COOLING OPERATION
After connecting the thermostat to the unit place the
system switch in cool mode. Adjust the set-point tempera-
ture below the room temperature. The compressor and fan
motors will start and cooling will begin. Place the set-point
temperature above the room temperature. The compressor
and condenser fan will stop and the indoor fan will remain
on for an additional sixty seconds.
IMPORTANT:
The start of the compressor will not take
place until the anti-short/random start time period has
elapsed.
ELECTRIC HEAT OPERATION
Place the thermostat system switch in heat mode.
Adjust the set-point temperature above the room tempera-
ture. The electric heat will energize along with the indoor
fan motor. Heating will continue so long as the set-point
remains above room temperature. Next place the set-point
temperature below room temperature. The Electric heater
will switch off and the indoor fan will remain on for an ad-
ditional sixty seconds.
HYDRONIC HEAT OPERATION
(Optional)
An optional hydronic heat package may be selected
in lieu of electric heat. Heating operation is essentially the
same as that of units with electric heat. With the thermostat
system switch set to heat and the set-point temperature
above room temperature, the hydronic valve will open al-
lowing water to flow through the coil. The indoor fan will
also switch on and warm air will flow from the unit. Heating
will continue so long as the set-point remains above room
temperature. Place the set-point temperature below room
temperature. The hydronic valve will close and indoor fan
will switch off after the sixty-second purge time has elapsed.
The hydronic valve is a 24Vac normally open valve. Should
power be lost to the unit, the valve will default to the open
position.
HYDRONIC COIL FREEZE PROTECTION
The hydronic package is equipped with a thermostat
(freeze-stat) that is designed to prevent the hydronic coil
from freezing. At 35°F the thermostat will switch open the
hot water valve to prevent the coil from freezing. At 50°F
the thermostat will reset. If the room thermostat is not call-
ing for heat, the valve will close. The freeze stat is factory
pre-set and should never need adjusting. However, if the
adjustment screw is tampered with it will be necessary to
reset the freeze-stat. To set the freeze stat you will need a
medium flat bladed screwdriver. Turn the adjusting screw
counter-clockwise until it stops. Then slowly turn the ad-
justing screw clockwise approximatly 1/8 turn until a click
is detected. The freeze stat is now set.
CHOOSING A THERMOSTAT
Enviromaster International offers a thermostat that is
compatible with the VPAC/VPHP. This is a single stage
cool/heat, mercury bulb thermostat that can be used in all
Retroaire™ cooling, heating or heat pump applications. The
thermostat has an adjustable set-point range of between
55°F and 95°F. There are two independent, adjustable stops
that can limit the heating or cooling range of the thermostat.
A non-mercury, electronic thermostat is available if needed.
please contact the factory for more information.
SELECTING A COMPATIBLE THERMOSTAT
When selecting a thermostat other than those offered
by Enviromaster International, it is important to choose a
single stage heat/cool, 24V thermostat. For models 09-17,
do not select a thermostat that requires connection to a
“C” terminal since these units do not have provisions for
connecting to a “C” terminal. Only models 19 and 24 have
provisions for connecting a “C” terminal to the unit. If a
thermostat without a “C” terminal is used in a models 19 or
24, then it is important to insulate the unused brown “C” low
volt wire to prevent it from shorting at the thermostat.
COOLING ONLY WITH ELECTRIC OR
HYDRONIC HEAT
(VPAC Only)
Select a thermostat that is compatible with a cooling
- electric heat system. The thermostat should have “R”, “Y”,
“W” and “G” terminals.
HEAT PUMP WITH ELECTRIC HEAT
(VPHP Only)
Select a thermostat that is compatible with a cooling
- single stage heat - heat pump system. The thermostat
should have “R”, “Y”, “O” and “G” terminals. Retroaire™
units are single stage heating only. The electric heat and
heat pump will not operate simultaneously.
FAN OPERATION
Some thermostats are equipped with an auto/on fan
switch. When this switch is placed in the on position the
indoor fan will run continuous. When the switch is in the
auto position the indoor fan will cycle with the call for heat-
ing or cooling.
FAN PURGE
(Auto Mode Only)
After the room thermostat has been satisfied, the purge
feature allows the indoor fan to remain on for an additional
60 seconds. This increases efficiency by pulling the remain-
ing energy from the unit.
SEQUENCE OF OPERATION
Содержание VPAC
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