Unit Test to determine problem:
1. Detach feld control wiring connections from main unit.
2. Connect the 24V and FAN from the main unit together; only the impeller fan should run. Disconnect the wires.
3. Connect the 24V and DEHU from the main unit together; the compressor and impeller fan should run.
4. If these tests work, the main unit is working properly. You should check the hygrostat and feld control wiring for
problems next.
5. Remove the hygrostat from the mounting box and detach it from the feld installed control wiring. Connect the
DEHU, 24V, and FAN terminals from the hygrostat directly to the corresponding locations on the main unit. Leave
the, FLOAT and COM terminals disconnected!
6. Turn on the fan switch; the impeller fan should run. Turn of the fan switch.
7. Turn on the humidity control; the compressor and impeller fan should run.
8. If these tests work, the problem is most likely in the feld control wiring.
Filter Change Light Illuminated (Too Frequently):
1. Change flter if dirty.
2. Hold flter change button.
3. Conditions causing rapid cycling, disable flter change light.
7.4 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.
7.5 Impeller Fan Replacement
The motorized impeller fan is a unitary assembly consisting of the motor and impeller fan. If defective, the complete
assembly must be replaced.
1. Unplug the power cord.
2. Remove the access panel, and top panel.
3. Remove the screws attaching the impeller fan support bracket to the base.
4. Disconnect the impeller fan leads inside the electric box.
5. Remove fan/bracket assembly by removing 3 screws from the bracket and inlet ring assembly.
6. Remove the defective impeller fan from the bracket and replace with it with the new impeller fan.
7. Reassemble the new impeller fan by reversing the above procedure. Note: There are two pins on the backside of the
cabinet that must align with the two holes in the impeller fan support bracket.
7.6 Compressor/Capacitor Replacement
This compressor is equipped with a two terminal external overload and a run capacitor, but no start capacitor or relay
(See Figure 4).
7.6A Checking Compressor Motor Circuits
Perform the following tests if the impeller fan runs but the compressor does not with the fan switch and ventilation timer
OFF and the humidity control ON.
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