Therma-Stor Products Group 90H - Manual (Page 17)

16 Ultra-Aire 90H Installer’s & Owner’s Manual 17 Ultra-Aire 90H Installer’s & Owner’s Manual
Unit not providing ventilation. Ventilation timer not operating
correctly.
1. If timer is not functioning correctly reset timer and reprogram.
2. Check control wire connections (check connections at fresh
air damper also).
3. Defective fresh air damper.
4.Defective fan switch.
Unit removes some water, but not as much as expected.
1. Air temperature and/or humidity have dropped.
2. Humidity meter and or thermometer used are
out of calibration.
3. Unit has entered defrost cycle.
4. Air filter dirty.
5. Defective defrost thermostat.
6. Low refrigerant charge.
7. Air leak such as loose cover or ducting leaks.
8. Defective compressor.
9. Restrictive ducting.
10.Optional Condensate Pump Safety Switch open.
Unit Test to determine problem:
1. Detach field control wiring connections from main unit.
2. Connect the yellow and green pigtails from the main unit
together; only the fan should run. Disconnect the wires.
3. Connect the yellow and blue pigtails from the main unit
together; the compressor and fan should run.
4. If these tests work, the main unit is working properly. You
should check the control panel and field control wiring for
problems next.
5. Remove the control panel from the mounting box and detach
it from the field installed control wiring. Connect the blue,
yellow, and green wires from the control panel directly to the
corresponding colored pigtails on the main unit. Leave the
violet, white and red wires disconnected!
6. Turn on the fan switch; the fan should run. Turn off the fan
switch.
7. Turn on the humidity control; the compressor and fan should
run.
8. If these tests work, the problem is most likely in the field
control wiring.
11.3 Refrigerant Charging
If the refrigerant charge is lost due to service or a leak, a new
charge must be accurately weighed in. If any of the old charge is
left in the system, it must be recovered before weighing in the new
charge. Refer to the unit nameplate for the correct charge weight
and refrigerant type.
11.4 Compressor/Capacitor Replacement
This compressor is equipped with a two terminal external overload
and a run capacitor, but no start capacitor or relay.
CAUTION!
CAUTION-ELECTRICAL SHOCK HAZARD: Electrical power must
be present to perform some tests. These tests should be
performed by a qualified service person.
11.5 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 one 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.
11.6 Condensate Pump Kit
An optional condensate pump kit is available from the factory for
use with the UA-90H. 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 UA-90H to the blue
(#5) lead on the control panel. If the pump fails, this switch opens
the compressor control circuit and stops water production before
the reservoir overflows. The UA-90H will continue to ventilate or
circulate air as normal, but will not dehumidify until this switch
closes. See following pages for more information.
FOR HVAC INSTALLER ONLY