Graphing appliance power usage

[Brad Johnson]

I have a piece of equipment I suspect is tripping a breaker. Evidence is pointing to it but I can't actually catch it in the act. Is there some reasonably simple inline (plug in) way to capture and graph amp draw? I'd like to plug in the equipment, wait until the breaker trips, and be able to conclusively point at the equipment with either a "amp draw spiked and tripped the breaker" or "there was no spike in amp draw and the problem must be somewhere else".

Kill-A-Watt will give me live readings but it doesn't do anything time-based. Is there something else out there?

Brad

[dogmush]

Something like this is probably your best bet.

https://www.amazon.com/Multimeter-BTMETER-BT-570C-APP-Resistance-Temperature/dp/B07CFWL3SY/ref=pd_lpo_sbs_328_t_2?_encoding=UTF8&psc=1&refRID=353ZHESN1YNX6YZ3K53F

Not strictly speaking "in line", and not super accurate at that price but it should give you the info you need.

[K Frame]

Yeah, but it would be cheaper to replace the questionable appliance.

And all the others, too.

https://www.amazon.com/Extech-380803-Analyzer-Appliance-Datalogger/dp/B000LDLHRQ

[Brad Johnson]

Thanks for the suggestions. Unfortunately, in this case the "appliance" is a couple grand worth of lab dehumidifier. I have a sneaky feeling the compressor has locked up and/or shorted internally. I may just have to stand there and watch the thing for a bit to see if I can legit say I saw the power fails just as a particular cycle came on.

Brad

[K Frame]

Ah, it's at work. And I know why I assumed it was an appliance like a fridge.

See if you can find a service that has one of the diagnostic devices.

[Brad Johnson]

Moot point now. I went down to test all the outlets for polarity/ground and the unit vented magic smoke just as I walked in the room. Kinda definitive, that.

Brad

[K Frame]

It knew it was up against the power of the hive mind.

[230RN]

Not helpful, but.

The Radio Shack Digital Voltmeter Catalog 22-1812 had an RS-232 port on it which allowed data logging of all its functions with Windows XP and was less than $100. It made very pretty publication quality graphs. It does not work with Win7 64-bit (with an RS-232 to USB adaptor) at all.  There may be an equivalent out there, but my need for data logging went away a long time ago.

There may be a User of the Arduino computer in the Arduino User Groups who has programmed their devices to do data logging.  You might check around in the Groups.

Another suggestion would be to slam that circuit breaker on and off manually a couple of times to <ahem> "wake it up" to do its duty properly.  They can get old and cranky.  (And I note you are apparently in a high-humidity situation in general.)

More helpful:
https://www.dataloggerinc.com/data-logger-applications/

Terry, 230RN

REF (Apparently it had different catalog numbers at different times, but this is what mine looks like):
https://sigrok.org/wiki/RadioShack_22-812