What do you think this is?

This is an AC motor used in the indoor unit of Air con, the motor is the blower.
In the fourth picture you can see the motor winding connection
Even though there is 4 terminals, there are only 3 connection to the driver.
Which make me thinks that the driver is a inverter, underneath the PCB, there are hall sensors.
Any Idea what could be the blown components.

 

It seems a 3phase speed control.
Find the data sheet/application notes for that IC; it should show typical application with recommended component values.
They could be low value resistors for current limiting/sensing.

 

Yup!. Exactly what I though, but I cannot get any specs on the driver.
It's a fairchild chip no. is FTBVP5SH50.
My theory is one low value R and capacitor.
Now I can assume the resistance but still have no idea what the capacitance may be?
Just though there might be some one who has seen one of these.
Which can make my job a bit easier.
but alas...no such luck.

 

It could also be a "Brushless DC" motor; the're actually working on three phase power.

Since it looks like it says Panasonic on the label, see if you can find a Panasonic datasheet for a brushless DC motor driver in the range of your motor's current rating that matches.

Those burned resistors are likely current sense resistors. Something probably went wrong with the driver module, and it let too much current go through the sense resistors. You'll have to figure out what values to use once you can find the datasheet.

 

OK, so it's a Fairchild part.

Found a reference document on Fairchild's site regarding a design/process change that your IC was listed on, dated March 2006. So, it's not that old, but several parts on that list don't show up in searching their site. I suspect that your controller IC is one made to Panasonic's specifications, and you will likely have a hard time finding documentation for the IC.

You could write to Fairchild Semiconductor and ask them for a datasheet.

 

the way I see it only two components are gone to heaven.
They are connected to red wire VDC.

 

I have emailed to Fairchild's Singapore for the specs

 

it's a 3 phase 4 wire, rated at 280VDC to 320VDC 30W motor.
The circuit is an Inverter. that's all I found. The resistor is the Rsense of one of the phase winding. I found the value but now the capacitor is the main problem. It's a SMD cap rated at 400VDC but I donno what the uF is?