Mini Split: Outdoor Fan Not Spinning

[Psyfurius]

Hi. I have a Mini Split Inverter which turns ON, cools for 2 mins and then the temperature goes up. I went outside and I noticed that the compresor was ON, but the condenser fan wasn't spinning. I took out the Main Board and checked some components and I didn't found any issues. I measured the Motor Fan Capacitor which is attached to the chasis. Its a non-polar 2.5 uF 450VAC capacitor. It measured 1.4 uF. So I bought a new one and that didn't help.

So I measured the ohms between cables to check if the windings are good... but here's the problem. I don't know if I'm testing it correctly and if so... I don't know if the readings are aceptable or not. Here's a diagram of the fan motor:



I disconnected the fan motor and here are the results when testing Ohm between cables:

Red to Black: 30 M Ohms
Red to Yellow: 2.1 k Ohms
Yellow to Black: 30 M Ohms

Should I try other combinations? are this values good or bad?

I checked for continuity on each of the 5 cables with the motor chasis and non had continuity. I also checked the resistance between the ground / earth cable with the chasis and had 000.4 ohms

While the mini split was connected to the electricity, I checked the voltages of each cable by connecting the black probe to ground and the red probe to each of the 5 cables. Don't know if that's the correct method, but here we go...

Here the results:

Yellow: 125VAC
Red: 125VAC
Black: 125VAC
Blue: 179VAC (Capacitor cable)
Brown: 125VAC (Capacitor cable)

These 5 cables are connected to another conector were brown and blue connects to the capacitor and a red, yellow and black cables connects to the Main Board. So I tested those 3 pins on the backside of the board. Again, system on stand-by, black probe to the ground chasis and red probe to each one of the pins. All 3 measured 125VAC.

So at this point I'm not sure if I'm testing this the correct way or if the winding readings are good or bad... I would like your opinion guys. I'm trying to figured out if this is a Main Board or Fan Motor issue. Some one told me that maybe there's a bad 'thermal fuse' inside the motor windings, but the motor chasis has 4 big rivets and it would be a pain to open it.

Motor: YKT-48-6-206
Main Board: KFR-51W/BP2

 

[PoorUB]

Are you saying the unit is not cooling? What is the outdoor temperature? If it is cold outside the fan in the outdoor unit might not run.

 

[Psyfurius]

Are you saying the unit is not cooling? What is the outdoor temperature? If it is cold outside the fan in the outdoor unit might not run.

Outdoor 90 to 95 Farenheit. I live in Puerto Rico. The fan should be spinning.

 

[PoorUB]

Ok, most of the USA is freezing, so just checking.

Most manufacturers have recommended methods for testing. I would trry find troubleshooting for your unit. You may have to make a phone call.

 

[Psyfurius]

Ok, most of the USA is freezing, so just checking.

Most manufacturers have recommended methods for testing. I would trry find troubleshooting for your unit. You may have to make a phone call.

Already tried that. I called yesterday and the guy told me I’m out of the warrant which is 5 years. This unit has 5 years and 3 months… so he offered to send a technician for $250 dollars to do the testing and then another $250 for the second visit to install the correct part which I also have to pay… at this time it would be better to buy a new one. The issue is that… there’s no units in the Island. Everyone is out of stock cause of covid.

 

[wyliesdiesels]

Have you tried connecting the fan motor direct to 240v to see if it spins?

 

[Psyfurius]

Have you tried connecting the fan motor direct to 240v to see if it spins?

I disconnected the brown and blue wire from the capacitor and connected to L1 and L2 which are 125VAC each. So both were on 250VAC



the motor didn’t spin.

 

[wyliesdiesels]

I disconnected the brown and blue wire from the capacitor and connected to L1 and L2 which are 125VAC each. So both were on 250VAC



the motor didn’t spin.

Huh? Why would you disconnect the capacitor and connect line voltage to the capacitor leads on the motor?

The Capacitor needs to stay connected to blue and brown on the motor.

240v Line voltage goes to red and black.

 

[Psyfurius]

Huh? Why would you disconnect the capacitor and connect line voltage to the capacitor leads on the motor?

The Capacitor needs to stay connected to blue and brown on the motor.

240v Line voltage goes to red and black.

I asked a friend who works as an electrician and told me so. Well… I should test again tomorrow with the red and black cables.

but also… I wanted to share this I just found on a service manual which indicates the right Ohms values for red - black and blue - black. I think mine are off..

 

[wyliesdiesels]

Yeah 30Mohms is too high. Forgot to mention that. Probably a broken winding

 

[Jim greengo]

Is there a contactor on the unit?
If the new capacities is good,and you're getting 240v to and from the contactor I'd say motor is bad.

 

[Psyfurius]

So I connected the red and black Fan Motor cables directly to 240VAC. It didn’t turn ON.


Weird thing is… now black and red ohms changed from 30 M ohms to 13.3 M ohms. Si did Blue and Black…

 

[wyliesdiesels]

So I connected the red and black Fan Motor cables directly to 240VAC. It didn’t turn ON.


Weird thing is… now black and red ohms changed from 30 M ohms to 13.3 M ohms. Si did Blue and Black…

was the capacitor connected to the motor when you applied 240v to it?

 

[Psyfurius]

was the capacitor connected to the motor when you applied 240v to it?

Yes. I applied 240VAC through red and black wires while brown and blue were connected to the capacitor.

 

[Terry D]

Resistance is way to high. You have a bad motor

 

[Psyfurius]

Thank you guys. So I decided to buy a new motor and now it works.

 

[wyliesdiesels]

Great. Hopefully you have a guard to protect people from those blades...

 

[Psyfurius]

Great. Hopefully you have a guard to protect people from those blades...