6
Manufactured in Rome, NY, USA
VPAC/VPHP
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EMERGENCY HEAT (VPHP ONLY)
WARNING
Before accessing the control compartment, discon-
nect power to the unit. Failure to do so could result
in serious injury or electrical shock.
Should the heat pump system fail, it is possible to force
the control board into electric heat mode. This is a
temporary solution until the heat pump system can be
repaired. Locate the circuit board in the control sec-
tion of the unit. Locate the terminals where the out-
door sensor connects to the circuit board. Using a small
needle nose type pliers, disconnect one side of the
sensor from the circuit board. This will appear to the
circuit board as an outdoor coil freeze condition,
thereby energizing the electric resistance heater on
the call for heat.
ANTI-SHORT CYCLE TIMER RANDOM START
This feature will prevent compressor short cycling and
also prevent multiple units in a single facility from si-
multaneously starting following a power outage. This
delay on break feature ensures that the compressor
remains off between cycles until the three-minute time
delay period has elapsed, allowing system pressures
to equalize before restarting.
The random start feature, initiated after a power fail-
ure, will add a random time delay (between 5-120 sec-
onds) to the three-minute anti short cycle time follow-
ing a power outage. This will stagger the starting of
multiple units in a single facility allowing a building to
slowly go back on line when power is restored.
INDOOR COIL FREEZE PROTECTION
This feature will prevent the indoor coil from freeze up
in the cooling mode. Indoor coil freeze up can occur
due to a dirty air filter, low refrigerant charge or low
room or outdoor temperatures. This in turn can cause
compressor damage. Should a freeze condition be
detected, the compressor and condenser fan will be
switched off for a minimum of three minutes and until
the freeze condition is satisfied. During this time the
indoor fan will continue to run to aid in the defrost
process.
ELECTRIC HEAT OPERATION
Place the thermostat system switch in heat mode. Ad-
just the set-point temperature above the room tem-
perature. 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 additional 60 seconds.
HEAT PUMP COOLING OPERATION
(VPHP ONLY)
Cooling operation in a heat pump unit is described in
“Cooling Operation” above. The unit is equipped with
a reversing valve that is energized for cooling and de-
energized in heating mode.
HEAT PUMP HEATING OPERATION
(VPHP ONLY)
Heat pump units are “Limited Range” equipped with
back-up electric resistance heat. Limited range heat
pumps are designed to operate when outdoor tem-
peratures are between 75°F and 40°F and with a maxi-
mum indoor temperature of 80°F. When the outdoor
temperature falls below approximately 40°F the unit
will switch from heat pump to electric resistance heat.
Electric heat will then remain as the heat source until
the outdoor temperatures rise above 50°F. The VPHP
30-36 is a single-stage heating unit. The electric heat
and heat pump will not operate simultaneously.
To operate the unit in heating mode, it must first be
connected to an appropriate heat pump thermostat.
(See “Choosing A Thermostat”). Select heat on the
thermostat system switch. Then, adjust the set-point
temperature above the room temperature. The com-
pressor and fan motors will start and heating will be-
gin. If the outdoor temperature is below approximately
40°F the heat pump system will not operate. Electric
heat will then take over the heating demand. Heating
will continue so long as the set-point temperature re-
mains above the room temperature. Place the set-
point temperature below the room temperature. The
heating mode will cease and the indoor fan will re-
main 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.
