Can someone please help me identify this resistor?

[mitsu2k]

This is out of a Pridiom mini split unit. It is the power board. This component is completely charred however I was able to get a photo from a good board.
I know it is .015 ohms and 1% tolerance but that’s about it.

Thank you!!

[truclacicr]

https://www.google.com/search?imgtyp...Cisz%3Am&udm=2

DALE WSR-5, 5 watt, 1%

https://www.vishay.com/docs/31059/wsrhighpower.pdf (datasheet)

http://www.vishay.com/doc?30327 (markings, see page 2, top right)

[mitsu2k]

Thank you @truclacicr
I was able to find that info. Just having trouble finding the part number to order on Mouser

[mitsu2k]

Yay I think I found it. Part# WSR5R0150FEA

[truclacicr]

WSR5R0150Fxx, where xx = EA, EK, TA or BA

[lotas]

This powerful current resistor does not just burn out, check the three-phase power module for powering the compressor, there should be no short circuit or low resistance on these terminals.

[lotas]

Since you don't have a resistor now, check it like this.

[mitsu2k]

Thank you Lotas, I did check as you mentioned. I did not find any short circuit or low resistance across those terminals. However there are a bunch of bloated caps. I will be replacing them.


Edit: sorry, I take that back. There is a short between the “P” and “N” see last photo terminals. Any ideas?

[mitsu2k]

I cannot find any other shorts on the top side of the board. There is a large chip on the bottom side however. I have no idea what it is or how to test it. See photo.

[lotas]

Check between the three common terminals (-) and (+) bypassing the resistor, if there is a short, replace the module or look for a donor (the board itself), since the module can take the control processor with it...

[mitsu2k]

Ok I checked between (+ P) and the 3 common terminals and there was no short or low resistance between them. I also did the same between the (-N) and there also was no short or low resistance.

the only short seems to be between the +P and the -N.
is this normal?

hold on. I think I did it wrong. There is a short from P to one side of the resistor pad and also a short between the N and the same resistor pad

[mitsu2k]

Also I noticed on the processor one of the legs must have gotten really hot. There is some solder that looks to have melted out of the through hole and onto the leg. See photos

[lotas]

That's strange, then check this metal film capacitor, unsolder it.

[lotas]

Measure here again, this leg is +300v and the resistor that burned out passes through it -300v and this power supplies this IGBT module.

[mitsu2k]

I would love to unsolder the metal film cap however the pins are directly underneath the processor chip. I would have to remove that first and it looks like it would be a nightmare

[mitsu2k]

Ok measured between the pins you specified on the IGBT module and there is no short. I am reading exactly 135ohms between the one leg and to each of the 3 others

[lotas]

I would love to unsolder the metal film cap however the pins are directly underneath the processor chip. I would have to remove that first and it looks like it would be a nightmare

This is not a processor, but a power IGBT module, and this processor, which controls this module, when this module breaks down, it sometimes kills this processor, then that’s it, only the replacement of the entire board.

[lotas]

Ok measured between the pins you specified on the IGBT module and there is no short. I am reading exactly 135ohms between the one leg and to each of the 3 others

This shouldn't happen, which means the module is faulty.

[mitsu2k]

This shouldn't happen, which means the module is faulty.

What should I expect to see between them under normal conditions?

[mitsu2k]

This is not a processor, but a power IGBT module, and this processor, which controls this module, when this module breaks down, it sometimes kills this processor, then that’s it, only the replacement of the entire board.

I think I’m understanding now. So likely the IGBT module shorted, causing the current sense resistor to burn. Also this IGBT shorting also may have possibly caused the processor to go out.