southwales

Hello,
I have a 7-year-old Comfort Maker heat pump. The condenser unit runs for 4-5 minutes, (fan & compressor), suction line gets cold, but then fan shuts down and compressor continues to run. The start capacitor is a dual 5/40 uF, 440V and had leaked (sprayed) oil so I replaced it but still have the same problem.
Question does the fan motor have an internal thermal overload? Is this the next logical thing to suspect or could it be something in the controller board or something eles?
Thanks in advance for any help/advice.

 

yes, the motor has an internal thermal. If you're sure the motor is wired properly,check the voltage going to the motor. If that's ok, test the motor for an open winding.

 

To daddyjohn- Thanks for the help.

Checked the AC voltage, it's OK. Before turning the unit on I checked the motor windings across the 3 leads & they look OK. Turned unit on, it ran for 4-5 minutes and fan shut down. Checked motor again, now there is continuity between red/brown leads only & open between black/brown & black/red. After 10-15 minutes unit will turn on again.
I think the problem is leading to the thermal overload in the motor. Any last items I should check before I order a replacement motor?

 

How much amperage does the motor draw compared to the rating on the nameplate? If you're sure the new capacitor is good, it sounds like you probably have a bad motor.

 

Hi daddyjohn,
I think the motor is the problem with this unit. I’ve ordered a replacement part, but I’m questioning the dual run capacitor. This came up when I removed the fan motor and noticed that the motors label calls for a 3uF capacitor.
No service has been done on this unit since it was originally installed, so the parts are “as installed”.
When a tech installs a new unit does it typically come from the factory with all parts in place, i.e. the run capacitor, or would he install it in the field? The reason why I ask is the values on the capacitor. The original cap that was installed is rated 5/40uF, 440V, but the condenser fan motor, which is an Emerson 1086598 (model K55HXHDD8562) calls for a 3uF, 370V. Normally I would think the voltage isn’t that critical, increasing from 370V to 440V is OK just overrating, but what about the value? Could using a 5uF instead of the recommended 3uF affect the operation or shorten the life of the motor? Am I worrying about nothing? I have located a supplier for a 3/40uF, 440V dual capacitor.

 

Run capacitors can be + or _ 10% on the mfd rating and + or > on the vac rating. Replacements are usually made up in the field from truck stock. I remember once I had to replace a 2.8 uf capacitor [chinese made motor]. My choices were two 5 mfd's wired in parallel for 2.5 mfd. or one 5 mfd and one 7.5 mfd wired in series for 3 mfd. I did the series choice.

These came out a few years ago. Pricey but great for service trucks.

AmRad Engineering, Inc.