12v Mini Split AC Suddenly pulling 40% Higher Wattage

[angrynorwegian13]

I've been running a Nekpokka 12v Mini split for the last few weeks and up until the other day it was running flawlessly - It draws about 750W while running as it's rated on the product specs. All of a sudden, it fried the fuse. I replaced the fuse, checked all connections in my electrical cabinet, and noted that it was drawing about 1100w on its own now (including the conversion from 12-24v from my converter). It seemingly runs fine but the fuse clearly cant handle the amperage (oddly enough, the manufacturer included a 60A fuse which isn't even enough for the rated 750w draw).

Obviously I'll need to add a bigger fuse regardless, but I'd still like to identify what happened seemingly overnight. Do DC step-down converters go bad or degrade? I have a 120A converter to feed my 12v fuse panel and the AC unit (yes I know there are 24v version of these available now and that would be much simpler). I'm using the wiring and fuse panel included by the manufacturer, but the wire does get hot.

I ordered a hall-effect sensor to check amperage in converter input/output wire, to see if there's something happening there. Is there anything else I can check? Has anyone had any experience like this? Chalk it up to a cheap Chinese unit?

 

[Zapper77]

I've been running a Nekpokka 12v Mini split for the last few weeks and up until the other day it was running flawlessly - It draws about 750W while running as it's rated on the product specs. All of a sudden, it fried the fuse. I replaced the fuse, checked all connections in my electrical cabinet, and noted that it was drawing about 1100w on its own now (including the conversion from 12-24v from my converter). It seemingly runs fine but the fuse clearly cant handle the amperage (oddly enough, the manufacturer included a 60A fuse which isn't even enough for the rated 750w draw).

Obviously I'll need to add a bigger fuse regardless, but I'd still like to identify what happened seemingly overnight. Do DC step-down converters go bad or degrade? I have a 120A converter to feed my 12v fuse panel and the AC unit (yes I know there are 24v version of these available now and that would be much simpler). I'm using the wiring and fuse panel included by the manufacturer, but the wire does get hot.

I ordered a hall-effect sensor to check amperage in converter input/output wire, to see if there's something happening there. Is there anything else I can check? Has anyone had any experience like this? Chalk it up to a cheap Chinese unit?

Check voltage

 

[Shimmy]

Any change in humidity or outside temperature?

 

[angrynorwegian13]

Check voltage

Voltage coming out of the converter is 12.5, drops 12.3 after the fuse.

Any change in humidity or outside temperature?

Nothing dramatic, been around 100 or so every day with typical Houston humidity.

 

[hwy17]

Voltage coming out of the converter is 12.5, drops 12.3 after the fuse.

Is that under load?

 

[angrynorwegian13]

Is that under load?

Yes

 

[JWLV]

Maybe someone sat on the remote and pushed the button for turbo or high mode?

I have a MRCOOL mini split. Normal operation in high mode uses about 600-700 watts. In turbo it uses 900+ watts.