Therma-Stor Products Group Ultra-Aire 100V - Manual (Page 13)

Ultra-Aire does not run, try turning the humidity control clockwise
until it reaches the stop and the knob pointer points at “ON”.
The Ultra-Aire is equipped with a automatic defrost mechanism.
If the Ultra-Aire operates in conditions that develop frost on the
evaporator, it will sense the frost build-up and automatically defrost
the evaporator. The Ultra-Aire may not appear to be operating
correctly during the defrost sequence, but once the defrost is
completed, the Ultra-Aire will resume dehumidifying.
7.7B Programmable Ventilation Timer
The ventilation timer controls the fan and the motorized fresh
air damper. When the ventilation timer is activated, the central
conditioning unit will circulate the indoor air, and bring in fresh air
from outside. The ventilation timer should be set for the required
ventilation of the residence. The home should be ventilated with
fresh air whenever it is occupied. If the Ultra-Aire fails to ventilate
as expected, check that the time on the timer is correct. For the
timer to carry out the program schedule, the slide switch in the
upper left corner on the timer must be set to “AUTO”. The slide
switch in the upper right corner of the Ultra-Aire must be set to
“RUN”. Also check the programs on the timer to be sure that the
timer is calling for ventilation at the correct times. If the timer fails
to operate or operates erratically, reset the timer; see section 3.5 of
this manual.
7.8 Defrost Thermostat
The defrost thermostat is attached to the refrigerant suction tube
between the accumulator and the compressor. It will automatically
shut the compressor off if the low side refrigerant temperature
drops due to excessive frost formation on the evaporator coil.
The fan will continue to run, causing air to flow through the
evaporator coil and melt the ice. When the ice has melted, the
evaporator temperature will rise and the thermostat will restart the
compressor.
7.9 Electric Ventilation Damper
The electric ventilation damper is controlled by the ventilation timer.
The damper will open when the ventilation timer is activated to allow
fresh air into the structure through the 6" diameter fresh air inlet duct.
The electric ventilation damper will remain closed when the ventilation
timer is not activated to prevent over-ventilating the structure when
the unit is dehumidifying or recirculating the indoor air.
The electric ventilation timer operates on 24 Vac from the control
circuit. DO NOT connect high voltage to the damper motor or
damage to the motor may result. DO NOT force the blade of the
damper by hand or damage to the damper motor may result.
The damper opens in one direction only. The damper rotates very
slowly, allow sufficient time for the damper to cycle. The damper
will take approximately 1 minute to cycle from closed to open or
from open to closed.
If the electric ventilation damper fails to operate:
1. Check that the wiring is correct and that voltage is present at
the damper motor.
2. Check for any obstruction inside the damper.
If the electric ventilation damper fails to operate after performing
these checks, it must be replaced.
FOR HVAC INSTALLER AND HOMEOWNER
13 Ultra-Aire 100V Installer’s & Owner’s Manual