Using power profile for diagnostics


#1

Although this might not be the right forum I was thinking that the ability to look at the power profile of my kitchen fridge made me think of a few things.

It would seem that these profiles could be used as diagnostic data to determine if there is something wrong with a device. What made me think of this is the profile of my current kitchen fridge. It’s a GE 26.6 ft^2 side by side fridge. It seems that the compressor is running unusually long but I have no profile to compare it to. It’s even running long when it’s not regularly opened.

Granted, there are a lot of factors that can affect the power profile of a device, esp one like a fridge. Ambient temperature, thermostat set point, how often it’s opened and even what’s in it. But I would imagine that there is still a bounded profile that the power profile should follow before being considered problematic.

So, back to my original issue. Anyone have a fridge similar to this that can post a power profile so I can do a comparison?


#2

I’ve got the exact same fridge, not sure if the same vintage as mine is about 20 years old. But it is the same GE side-by-side and same size. The profile looks almost identical. I think you are asking Sense to do something it is not capable of. Since Sense does not actually measure the wattage of the device I believe (someone correct me if I am wrong) it can only determine if the device is on or off and can’t really tell you slight changes in its draw. It would seem to me that if it did the horizontal lines would not be perfect and would show variations. As to knowing how long the fridge runs for that might be something they could implement and have something like an IFTTT to alert you if it runs more than a predetermined time to warn you that perhaps the door was left open and it is running non-stop. Here is a graph from the last 12 hours or so of my unit.


#3

BTW I think newer fridges run for much shorter times but pull a lot more power when they run. I recall seeing others post some pictures showing theirs pulling something like 1200 watts but only running for like 3-5 minutes at a time.


#4

Your cycle times seem much more appropriate from what I’ve seen on another fridge we have. In my profile we have compressor cycle times ranging from 30 mins to over 90 mins.Those seem really long. Not sure if that’s a device malfunction or it’s doing what it’s supposed to. Moreover, some of those long cycle times come when our house is at it’s coolest which would lead me to believe it would cycle less.

I periodically clean the coils and it’s not like I have it set super cold.


#5

Perhaps you could be correct, but I have at times seen long cycle times like those in the red boxes too. I am not sure if they are real or not. I have seen with a few devices that I have manually shut off Sense thinks they are still on and while total power drops Sense still shows bubbles with usage for the device. Thus, each of the red boxes might actually be two shorter runs with a gap and Sense just missed the going off in between. Or, it could be a long run. I would be interested in hearing from someone @SENSE support commenting on this.


#6

I’m certain this is one of the original intended functions of Sense. When we bought our house, we had a succession of things fail - ac motor, fridge,… Something else too, but we’re waiting on our hot water heater now. I’d been writing how helpful it would have been to know that before we bought. That should be apparent in the nature of the curves and their frequency. As more data is collected on specific devices, more data will become available on what they look like when they begin to fail.


#7

Here’s our new Samsung rf23… Negligible consumption (that 210w is everything/always on, the bumps from the fridge represent 20w-ish), although every couple hours it has a separate plateau of 50w or so.


#8

Are their any parts you need to clean to ensure that the unit works correctly? My fridge needs to have some parts vacuumed to ensure they are working at their best. This can affect the run times of the appliance.


#9

Yes. Often referred to as “the coils” your refrigeration has condenser coils that are typically located either along the back or the bottom of it. Access can sometimes be tricky - especially for coils that run under the refrigerator. They make a verity of brushes and attachments to clean condenser coils:


#10

Wait…this is confusing. Are you saying that your fridge compressor is running 24x7 at 210w? That’s a lot.


#11

No - my always on is 200ish (baseline there), the fridge only uses about
20w briefly with occasional plateaus up to 50w or so :slight_smile: I’m still trying
to get things working so I don’t have my fridge parsed out like you guys
yet.


#12

Ahhh, I understand now. Sorry I was being a bit slow on the uptake.


#13

My fridge freezer is still a mystery to me. I have one device that was identified as a fridge and for the first 8 days it spiked to 768w or 626w for a second and then settled to 116w for usually 30-60 minutes.

Then the plateaus disappeared for about a day and a new 1052w spike started appearing. From late on October 6th 2016 I’ve been seeing this pattern consistently. It uses either 1,116w, 734w, 513w, right up until January 6, 2017. Since midnight on that date I’ve seen absolutely no usage on the fridge device (and Sense is reporting for everything else).

It appears that Sense was seeing this learned fridge device with one type of load for about a week and then it was replaced with a different load for months, and now that has just disappeared altogether. This is news to me, and it looks like I have another device learning problem to report.


#14

I had a similar thing for my 1stt floor frige. It was identified months ago and then at some point it identified another device that turned out to be the same fridge. Sometimes usage would show on one and then usage would sometimes show on the other. Then it started showing on both at once at times. Now those devices seem to come on when the fridge is in fact not running (as proven by my Kill-A-Watt) but show usage that is roughly double what the fridge actually draws. I have no clue what these devices represent anymore as I don’t have any other motors like this in the house. I thought maybe it had them representing my two hvac systems but proved that to be false yesterday. At a total loss as to what is going on now.


#15

“My fridge freezer is still a mystery to me. I have one device that was identified as a fridge and for the first 8 days it spiked to 768w or 626w for a second and then settled to 116w for usually 30-60 minutes.”

The initial spike is pretty typical as this is the starter capacitor draw and then should almost immediately settle down to the compressor only load.


#16

These are my two units. The Kelvinator 12.5cuft standing Freezer runs more on a pattern, the Samsung rf197 17.8cuft 3 door fridge is more sporadic(maybe from the constant opening and closing). Both are less than 5 yrs old.


#17

Hmmm…I’m thinking if you zoom in to the second one it would be closer to my profile. It just seems that compressor run times of >1h 30m seems excessive.


#18

The run profile might be down to design. I’m sure I’ve read longer refrigerator compressor run time is the way newer energy star appliances are designed. I’ll post a link if I can dig it up.

My Kelvinator freezer is a manual defrost; The Samsung is frost free(was energy star rated when purchased)

Average run time shows 18mins(276 starts) vs 44mins(107 starts) for the Samsung. The Kelvinator has been detected for 16 days and the Samsung 14 days ago.

Here is a close up on the Samsung.


#19

Yea - mine is still almost 50% longer compressor run times with a higher draw (200w avg). I seem to have two profiles for that fridge with similar cycle run times - one at a 100w avg and one at a 200w avg. Both of those draw seems to have times when they are pulling that for almost 90 minutes.


#20

Two average watts sounds like your refrigerator has dual evaporators. Samsung calls it Twin cooling. GE has it too. A little technical but basically these are the common ones.

  • Single compressor / single evaporator
  • Single compressor / dual evaporator
  • Dual compressor / dual evaporator

Single/single are the older generation refrigerators and current single compartment freezers.

Dual/dual are mostly high ends refrigerators. One pair for the fridge portion the other for the freezer portion…I think Sense should identify these as two unique devices.

Single/dual should have two averages. The evaporator going to the fridge porton can be 1 ton and the evaporator going to the freezer can be 2 ton affecting the watts. There will be a valve switching the refrigerant between the two evaporators depending on which section of the refrigerator is calling for cooling.