Fridge Monitoring

[sparkman]

Hi all,

After recently hooking up zwave devices to monitor power consumption on my appliances and monitor on/off status, I thought I could do more than that, especially with our fridges. I had thought about hooking up door sensors to them and temperature sensors inside so that I could be alerted if there were problems. However, I realized that the power usage patterns are also good indicators of how the fridge is doing. I started with one fridge and determined it had the following power usage:

idle: 0-15 Watt
door open: 60 Watt (due to light bulb being on)
compressor running during cooling cycle: 140-160 Watt
defrost cycle: 360-400 Watt

If one or both of the doors are open during the cooling or defrost cycles, then the power draw increases by an equivalent amount. Our other fridge has a similar pattern, but with different values.

Common problems with fridges are doors being left open, being stuck in the defrost cycle, the defrost cycle not coming on at all, the compressor running continuously due to a refrigerant leak, or the compressor not running at all. All these can be detected by monitoring the power usage and then triggering alerts if the power usage becomes abnormal.

I created 3 virtual devices for each fridge, one called Status (on/off), one called Mode (idle/cooling/defrost), and one called Door (closed/open) along with a parent device which I used to group them:






I then used a script that was called when the fridge's power consumption changed. Three parameters, separated by commas, need to be passed to it: the Door Device, the Mode Device and the device with the power usage. The script updates the virtual devices as needed. The Status device is directly updated by events. I used a similar script for the other fridge because the ranges were different.

Sub Main(ByVal Parms As String)

	Dim logName As String = "Fridge Status"		'set log type for HS log
	Dim Debug As Boolean = False				'set to True if the script give you errors and it will provide additional info in the HS3 log to help troubleshoot
	Dim ParmArray() as String
	ParmArray = Parms.tostring.split(",")
	dim DoorDev as Double = CDbl(ParmArray(0))		'reference ID of the Door device
	dim ModeDev as Double = CDbl(ParmArray(1))		'reference ID of the Mode device
	dim PowerDev as Double = CDbl(ParmArray(2))		'reference ID of the Power device
	Dim Power As Double = hs.DeviceValueEx(PowerDev)
	If Debug Then hs.writelog(logName,CStr(Power))
	Select Case Power
		Case 0 To 49.9999999
			If hs.DeviceValue(DoorDev) = 100 Then hs.SetDeviceValueByRef(DoorDev,0,True)
			If hs.DeviceValue(ModeDev) <> 1 Then hs.SetDeviceValueByRef(ModeDev,1,True)
		Case 50 To 124.9999999
			If hs.DeviceValue(DoorDev) = 0 Then hs.SetDeviceValueByRef(DoorDev,100,True)
			If hs.DeviceValue(ModeDev) <> 1 Then hs.SetDeviceValueByRef(ModeDev,1,True)
		Case 125 To 189.999999
			If hs.DeviceValue(DoorDev) = 100 Then hs.SetDeviceValueByRef(DoorDev,0,True)
			If hs.DeviceValue(ModeDev) <> 2 Then hs.SetDeviceValueByRef(ModeDev,2,True)
		Case 190 To 274.999999
			If hs.DeviceValue(DoorDev) = 0 Then hs.SetDeviceValueByRef(DoorDev,100,True)
			If hs.DeviceValue(ModeDev) <> 2 Then hs.SetDeviceValueByRef(ModeDev,2,True)
		Case 275 To 424.999999
			If hs.DeviceValue(DoorDev) = 100 Then hs.SetDeviceValueByRef(DoorDev,0,True)
			If hs.DeviceValue(ModeDev) <> 3 Then hs.SetDeviceValueByRef(ModeDev,3,True)
		Case 425 To 599.999999
			If hs.DeviceValue(DoorDev) = 0 Then hs.SetDeviceValueByRef(DoorDev,100,True)
			If hs.DeviceValue(ModeDev) <> 3 Then hs.SetDeviceValueByRef(ModeDev,3,True)
	End Select

End Sub

Other events are used to monitor the devices and will send alerts as needed. See the next post for details.

Cheers
Al

[sparkman]

Here are the events that maintain the Status device. A timer is used to keep track of the run time:




Here are events that maintain a counter to determine if the defrost cycle is coming on:



Here are the events that generate the alerts (using the Pushover plugin):

[sparkman]

Here are the screenshots of the devices' status-graphics tabs:

Door Device


Mode Device


Status Device


zip file with the icons is attached.

[TomTom]

Wow! Nice Al. This is very useful. I like how you approached this problem, and your solution to this. I'm saving this page. Someday I'll get to this [emoji849]


Sent from my iPhone

[Steve Q]

Excellent work! The script is very nice. I never knew the Case function could encompass a range of results. This is really helpful! Your approach would also work on lots of appliances that use multiple power levels. Things like washing machine, dryer, air conditioner, etc.

Thanks for sharing.
Steve Q


Sent from my iPad using Tapatalk

[sonypoolplr]

Thank you for sharing all of this. I have been recently started thinking about monitoring usage in my house and this will be a big help.

[sparkman]

Thanks for the kind words everyone. I've updated the third post to show how the 3 devices are configured and have attached a zip with the icons.

Here's a screen shot of all of the appliances I'm monitoring so far:



Cheers
Al

[Steve Q]

Perhaps you mentioned it, I did not see it, how are you measuring the power? Is it being polled continuously? Perhaps it's not important, but can you actually detect opening and closing the refrigerator door to remove a milk carton? It takes 3-5 seconds?

Steve Q


Sent from my iPad using Tapatalk

[sparkman]

Perhaps you mentioned it, I did not see it, how are you measuring the power? Is it being polled continuously? Perhaps it's not important, but can you actually detect opening and closing the refrigerator door to remove a milk carton? It takes 3-5 seconds?

Steve Q

Hi Steve, for the fridges, I'm using a HEM with current clamps on the wires to them. I send data about once every 60 seconds, but they do send faster with changes in wattage. My intent is not to know every time a fridge is opened, only if a door is accidentally left open too long. You could have them send the data more often if you wanted to track it to that level.

For the other appliances that I'm monitoring, I used a mixture of devices, including EnerWave ZW15RM, Aeotec HEM, Aeotec ZW096 Smart Switch, Aeotec DSC06106 and Aeotec ZW078.

Cheers
Al

[Steve Q]

Thanks Al, I was thinking about an event to sound a very loud siren when the fridge door is opened after 9:00 PM! [emoji32][emoji12]

Steve Q


Sent from my iPad using Tapatalk

[sparkman]

Thanks Al, I was thinking about an event to sound a very loud siren when the fridge door is opened after 9:00 PM! [emoji32][emoji12]

Steve Q

Lol, I might have to do something like that for the beer fridge when the boys get older.

Cheers
Al

[ServiceXp]

Nice! Can your script determine:

Compressor is running, and the door is then opened?

[sparkman]

Nice! Can your script determine:

Compressor is running, and the door is then opened?

Thanks and yes, that works too:



Cheers
Al

[sparkman]

I set up a chart of the fridges' power usage using the jon00's database charting tool to validate some of my assumptions:



Everything looks ok, although sometimes the script may assume a door is opened due to the initial in-rush when the compressor starts up dpeending on how large the "surge" is. Typically these are detected as small spikes, but occasionally a larger spike is detected.

Cheers
Al

[sparkman]

Updated the original posts with additional events that monitor for the defrost cycle not working at all.