Therma-Stor Products Group UA-150H - Manual (Page 18)

If sludge is evident in the discharge line, it will likely be found in the
suction line. This indicates the compressor burned out will running.
Sludge and acid have been pumped throughout the system. Several
changes of the liquid and suction filter/driers will probably be
necessary to cleanse the system.
5. Correct the system fault that caused the burn out. Consult the
factory for advice.
6. Install the replacement compressor with a new capacitor and
an oversized liquid line filter.
In a running burn out, install an oversized suction line filter/drier
between the accumulator and compressor. Thoroughly flush the
accumulator with refrigerant to remove all trapped sludge and to
prevent the oil hole from becoming plugged. A standing burn out
does not require a suction line filter/drier.
7. Evacuate the system with a good vacuum pump and accurate
vacuum gauge. Leave the pump on the system for at least an
hour.
8. Operate the system for a short period of time, monitoring the
suction pressure to determine that the suction filter is not
becoming plugged. Replace the suction filter/drier if pressure
drop occurs. If a severe running burn out has occurred, several
filter/driers may have to be replaced to remove all of the acid
and moisture.
NOTE: NEVER use the compressor to evacuate the system or any
part of it.
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 UA-150H 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 UA-150H 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 UA-150H. Check the
connections between the UA-150H, 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 dial set
point. It opens when the RH drops 4 to 6% below the set point. If the
UA-150H does not run, try turning the humidity control clockwise
until it reaches the stop and the knob pointer points at “Max Dry”
(see back of control panel cover). ). If it still does not run, remove the
stop screw from the panel and turn the knob farther. If it then runs,
the humidity control is out of calibration or the RH is below 40%.
The UA-150H is equipped with an automatic defrost mechanism.
If the UA-150H operates in conditions that develop frost on the
evaporator, it will sense the frost build-up and automatically defrost
the evaporator. The UA-150H may not appear to be operating
correctly during the defrost sequence, but once the defrost sequence
is completed, the UA-150H will resume dehumidifying.
7.7B Programmable Ventilation Timer
The ventilation timer controls the impeller fan and the motorized
fresh air damper. When the ventilation timer is activated, the UA-
150H 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 UA-150H 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 UA-150H
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 4.5 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 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 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.
FOR HVAC INSTALLER ONLY
18 Ultra-Aire 150H Installer’s & Owner’s Manual