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Eubank 7AA1024H-1060H & 7AA2024H-2060H I&O Manual 03/2021 Rev.1
4.3 Compressor Troubleshooting
Obtain the heat pump's model number and serial number, the compressor's model number and contact
Airxcel Commercial Group for compressor specifications.
It is important to rule out other component failures before condemning the compressor.
The following electrical tests will aid diagnosis on single phase 7AA units:
1.
Start-Up Voltage:
Measure the voltage at the compressor contactor during start-up. The voltage must
exceed the minimum shown in Table 8, section 2.2, or compressor failure is likely. A low voltage
condition must be corrected.
2.
Running Amperage:
Connect a clip-on type ammeter to the (common) lead to the compressor.
Turn on the supply voltage and energize the unit. The compressor will initially draw high amperage;
it should soon drop to the RLA value or less. If the amperage stays high, check the motor winding
resistances.
NOTE:
Feel the top of the compressor to see if it has overheated. If it is hot, the internal overload
may be open. You may have to wait several hours for it to reset.
3.
High Voltage/Insulation Test:
Test internal leakage with a megohmeter. Attach one lead to the
compressor case on a bare metal tube and to each compressor terminal to test the motor windings. A
short circuit at a high voltages indicates a motor defect. Do not do this test under vacuum.
4. On single phase models, check the capacitor by substitution.
4.4 Electric Heat Controls
Figure 10 - Typical Configuration for Single Element Heater
The electric heater assembly can have up to three individual heating elements. Each individual heating
element is protected against overheating by its own dual function thermal cut-out switch. Additionally,
a separate single function thermal cut-out switch protects the entire heater assembly.
