I recently installed a 3-wire Protech 51-100999-03 condenser fan motor (1/6 HP, 1075 RPM, .73 A, CCW rotation) and a 24" dual blade, 28 degree pitch, CCW fan blade. New motor has same specs as old motor (TradePro TP-C16-1SP2 6-wire motor) except old motor was rated at 1.2 A.
In addition, I installed a Protech 50 + 3 μF dual run capacitor and a Protactor single-pole contactor.
To wire the circuit, I wired:
- line voltage wire (white) on L1
- line voltage wire (black) on L2
- 24v wire (yellow) on coil of contactor
- 24v wire (black) on other coil of contactor
- red wire from compressor on T1
- black wire from compressor on T2
- orange jumper wire on T1 (and on Com terminal of capacitor)
- purple compressor wire on Herm terminal of capacitor
- ground wire attached to ground strip on condenser assembly
- orange jumper wire on T1 and on Com terminal of capacitor
- orange wire from condenser fan motor on Com terminal of capacitor
- black wire from condenser fan motor on T2
- brown wire from condenser fan motor on Fan terminal of capacitor
The condenser fan motor will run for perhaps 30 minutes and then it noticeably overheats (burning hot) and stops.
I tested the capacitor using Fluke DMM. Herm-Com tested at 50.2 μF and Fan-Com tested at 3.2 μF. The old wiring configuration used two capacitors: one for the condenser fan motor and another for the compressor. I decided just to use a dual run capacitor.
I warped the old fan blade while removing it from old condenser fan motor. I had it on the new motor for an hour or two. It was moving air, but I could see a slightly wobble at the shaft. Not extreme, but noticeable. So, after the condenser fan motor overheated the first time, I turned the power off at sub-panel. I bought a new blade yesterday (24" dual blade, CCW rotation, 28 deg. pitch). The same overheating problem occurs before and after the fan blade replacement.
While it ran with the new blade, it was pushing a good amount of air out the top of the assembly. No air coming out from the sides, so I suspect the blade is located properly on the shaft.
I disassembled the entire cage for the condenser to paint it. While I had it diassembled, I cleaned the coils. The overheating problem occurred before and after I cleaned the coils.
Now, I have no idea what could be causing the overheating except for a faulty motor. Any other ideas?