Therma-Stor Ultra Aire XT105H, Owner'S Manual

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Ultra-Aire XT105H, XT155H, and XT205H Installer’s & Owner’s Manual
7.6C Replacing a Compressor, Nonburn Out
Remove the refrigerant from the system. Replace the compressor
and liquid line filter/drier. Charge the system to 50 PSIG and check
for leaks. Remove the charge and weigh in the refrigerant quantity
listed on the nameplate. Operate the system to verify performance.
7.7 Remote Controls
The Ultra-Aire XT is controlled by devices mounted on a panel that
is remote from the unit. You may or may not have the devices listed
below depending on the model of the remote control panel you
purchased. If the Ultra-Aire XT fails to operate as desired, always
check the settings of the controls to insure that they are correct.
Check that the controls are receiving 24Vac from the Ultra-Aire XT.
Check the connections between the Ultra-Aire XT, the control panel,
and the field control wiring.
7.7A Humidity Control
The humidity control is an adjustable switch that closes when the
relative humidity of the air in which it is located rises to the screen
set point.
The Ultra-Aire XT is equipped with an automatic defrost
mechanism. If the Ultra-Aire XT operates in conditions that
develop frost on the evaporator, it will sense the frost build-up
and automatically defrost the evaporator. The Ultra-Aire XT may
not appear to be operating correctly during the defrost sequence,
but once the defrost sequence is completed, the Ultra-Aire XT will
resume dehumidifying.
7.7B Programmable Ventilation Timer –
DEH3000/3000R
The ventilation timer controls the impeller fan and the motorized
fresh air damper. When the ventilation timer is activated, the
Ultra-Aire XT 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 as suggested by applicable codes and standards.
If the Ultra-Aire XT fails to ventilate as expected, check that the
time on the timer is correct. Also check the programs on the timer
to be sure that the timer is calling for ventilation at the correct
times.
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
impeller 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 damper will open when the ventilation is called for, allowing
fresh air into the structure through the fresh air inlet duct. The
electric ventilation damper will remain closed when the ventilation
is not activated in order to prevent over-ventilating the structure
when the unit is dehumidifying or recirculating the indoor air. The
electric ventilation damper operates on 24 Vac from the control
circuit. DO NOT connect high voltage to the damper motor or
damage to the motor will 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.
7.10 Condensate Pump Kit
An optional condensate pump kit is available from the factory for
use with the Ultra-Aire XT. Condensate is automatically pumped
to a remote location when the water level in the pump's reservoir
rises to close the float switch.
The pump also contains a safety float switch. The white leads
from this switch extend from beneath the pump cover. This switch
should be installed in series with the field wire that connects the
blue (#5) lead from the Ultra-Aire XT to the blue (#5) lead on the
control panel. Contact a certified electrician to install the Safety
Overflow Switch (optional).
If the pump fails, this switch opens the compressor control circuit
and stops water production before the reservoir overflows. The
Ultra-Aire XT will continue to ventilate or circulate air as normal, but
will not dehumidify until this switch closes.