Could you please help me identify this IC from an outdoor air condition unit. It doesn't have any markings on it.

 

Appears to be a ECM motor controller according to the pin labeling (U,V,W).
Max.

 

Appears to be a ECM motor controller according to the pin labeling (U,V,W).
Max.

Thanks Max, I'm wondering if there is any way of trouble shooting the IC.

 

Without getting some kind of specs on it, pretty much in the dark!
Why do you suspect it?
Max.

 

The unit's compressor doesn't turn on. The error code I get asks me to check the DC voltage between P(+) and N(-) pins of the IC. The manual points towards faulty a power supply. I just wanted to check whether the IC works (general enquiry ).
I've attached a screenshot of the error code.
Another thing I'm a bit freaked out is the copper-ish colour plate on the chip. I'm afraid that its something toxic like beryllium-oxide. The plate is not damaged but I'd rather not handle it if turns out to be something like that. Do you have any idea what that could be.
Thanks so much

 

Another thing I'm a bit freaked out is the copper-ish colour plate on the chip. I'm afraid that its something toxic like beryllium-oxide. The plate is not damaged but I'd rather not handle it if turns out to be something like that. Do you have any idea what that could be.
Thanks so much

Suspect it is just a heat-sink/ heat-dissipation for the IC.
I would have thought the compressor was just a typical induction motor, variable speed etc is not usually required for a compressor?
So what does P & N measure?
Max.

 

If you want the markings of the chip you will have to remove it as they are on the other side. Its a variable freq drive chip for the compressor, in inverter type aircons now the compressor & fans are variable speed to conserve power usage. If theres no DC voltage then it will need to be sorted first.

 

The error code I get asks me to check the DC voltage between P(+) and N(-) pins of the IC.

Well, what you you see for a voltage between P(+) and N(-)?

 

I can see a ECM motor for a fan, but cannot see why you would need it for a compressor?
Where is @#12 when you need him!
Max.

 

Voltage between the pins is 0V so yeah there is an issue with with the power supply. The unit got busted when some one accidentally jammed in a metal rod into the unit while it was running. It caused the fan to jam stop and also it tripped the main breaker - the unit ran afterwards but we noticed that the compressor was not turning on.

 

So it could be the ECM fan motor.
Max.

 

Please post a picture of the full board -- or if you know the model number and/or where a manual might be available online, that would be helpful. If you have 0 volts across the IC power input pins, it's likely a problem -before- that IC.

 

Beryllium oxide is a white ceramic. That is almost certainly just a pure copper slug with the actual IC (or multiple chips) mounted on the underside of it. It will be intended to be mounted to a heatskink. If there was no heatsink then it is a clear indication it was used for some very light load.

Beryllium oxide is a rarity in power semiconductors these days, though it is probably still used in some things like isolated stud mount rectifiers and some high power RF transistors. It is safe as a solid, but the dust can be extremely hazardous.

Note that J167 to the lower left of the IC is broken. It actually looks like it has been melted at the end.

 

That copper looking piece is copper. The heat sink that should be attached is missing. And if there is no supply voltage then there is a problem with the supply. AND yes, the compressor may be a 3-phase brushless motor because the required power does vary, depending on the heat load. But don't bother removing the IC because a replacement is not available. The intention os that you must replace the circuit board to fix it. One more concern is that if a steel rod was jammed through the fan, it may also have damaged the condenser core, causing a leak. If the freon has all leaked out then the low-pressure protection switch has opened and the compressor will not be able to run. Thus there are several things to check before digging in to the control circuit board, some of them more obvious and others not so obvious.

 

Note that J167 to the lower left of the IC is broken. It actually looks like it has been melted at the end.

Yep the jumper snapped off while I was cleaning the board. I have replaced the jumper

Please post a picture of the full board -- or if you know the model number and/or where a manual might be available online, that would be helpful. If you have 0 volts across the IC power input pins, it's likely a problem -before- that IC.

I couldn't find a schematic online - sure I'll post a picture of the full board.

 

The compressor unit outside is a standalone unit, I would check to see the low voltage wires coming to the condensing unit is getting power first. If you are getting the power at the condensing unit then you know the problem is in the condensing unit.

The reason for the above is that any damage to the condensing unit has no impact on the furnace (the board inside the furnace). In other words the furnace has no way of knowing if the outdoor unit is working or not, the only thing it does is sends a low voltage to the condensing unit.

 

Before going any farther with a detailed checking it would be worth while to verify that both of the pressure switches are still enabling the compressor. If there was an impact to the condenser it could have created a leak, at which point the low pressure cutoff would keep the compressor from running..
Also, with the circuit board, if one jumper came off wjile you were cleaning the board, there may be other poor connections causing problems. So I suggest a very close inspection with a magnifier and a bright light.Poor connections are cheap to fix and a sneaky source of problems.Also, check the circuit associated with the fan that w as stopped. Something may have failed in that area, possibly a fuse. Again, a simple and cheap thing to fix if it has failed.

 

A bit of update, we were able to borrow another board from a working unit to see whether everything else works,and it does work. Have been running it for sometime now

 

Glad to hear that the rest of the system is OK, since repairing a freon leak can be expensive. Now, since the power supply voltage was missing on the failed board, a good picture would help us locate the failed part, which may be a fuse, or have acted as a fuse. So please post an in-focus picture.

 

The part Number, if it is on the chip is probably under the copper heat spreader, otherwis on the "belly" of the chip if there at all,