Initial Review - WattNode Advanced

[AndrewF]

As suggested in a previous thread, I am posting up my initial review of the WattNode I bought for monitoring my home power usage.

I bought the Advanced Wattnode Pulse (http://www.ccontrolsys.com/products/pulse_output.html) to monitor my 200 amp 240vac service. I picked this solution as it would scale with two additional current transformers for when we upgrade to 400 amp service. It also can monitor reverse power should I ever decide to put a solar array or wind generator up.

I had the unit setup for outputting pulses at a higher than normal rate. (5333 pulses per KW/hr) (80HZ) as well as the default 20Hz rate. This would enable me to graph and log smaller changes in power usage, such as the turning on of a 100 watt bulb in the past minute.

I currently have a 1-wire DS2423 chip monitoring the pulses at both output scales.

I have a perl script gathering the pulse count every 60 seconds and inserting a new record into mysql of the current counter reading. This has been working well for about 4 days so far.

I am still trying to figure out how to interpret the data as I only input the raw data, not the count change. If anyone has some mysql logic/scripts for processing the counts of a DS2423 chip and is willing to share them with me, I would appreciate it.

Once I have the frontend graph functions figured out, I'll try to post up additional information on how the system has been working out.

 

[politics123]

Do you know how to use triggers?

Create a reference table that stores just the high-value (eg: the last recorded count)

Create a trigger on your log table that compares the current count with the other table, and then records the delta in your log table. Also, update the high-value in your reference table.

 

[AndrewF]

Do you know how to use triggers?

Create a reference table that stores just the high-value (eg: the last recorded count)

Create a trigger on your log table that compares the current count with the other table, and then records the delta in your log table. Also, update the high-value in your reference table.

I don't, but now that you mention it, I will learn. Off to google

What I didnt want to do is a bunch of logic on the insert script or the PHP page, so it looks like triggers will work better as it keeps the processing on the server and would scale very well, regardless of the number of visitors to the page.

Thanks for the pointer.

I'll report back as I make progress.

 

[AndrewF]

Update on the WattNode.

So once I got the MySql triggers and scripts worked out (thanks for the pointers) I noticed I was not getting consistent readings from the Wattnode when Paired with a DS2423 counter board from hobby-boards.

The WattNode would consistently report higher usage than what the electric meter reported. (actual usage 9 KWHR vs Wattnode 19.6 KWHR)

I contacted Steve at ControlSys(wattnode) and we double checked my formulas and everything checked out. He suggested I run some tests on the cabling and make sure I had the polarity setup properly with the DS2423. That piece of information found the problem.

On the DS2423 board, there are three terminals. (A, B and 5+ )
On the Wattnode, there are 4 terminals (COM, P1, P2, P3)
I have my WattNode set to give out 80 HZ pulses on P1 and 20 HZ pulses on P3. (P2 gives out pulses for reverse energy..ie netmetering with wind/solar power)

On the DS2423 the A/B ports are (negative) or less voltage than what would be on the 5+ pin.
On the Wattnode the P1/P2/P3 ports are (positive) or more voltage than on the COM port.

I had the COM from the Wattnode hookd to the 5+ port on the DS2423 and P1 to A and P3 to B.

Once I wired the Wattnode (com) to the DS2423 (A) and the Wattnode (p1) to the DS2423(5+) the counter was dead on.

Looking at the raw data now, I can clearly see there was a problem before.

Below is a snapshot of one of my php pages that shows me in realtime the power used per day...with the current day being updated every 60 seconds.

The other two charts are just of the raw data...so I can see that the steady state of my house (no hvac) is .84 Kw/hr or $2.12/day.

 

[BraveSirRobbin]

Andrew, this is all great info, thanks for taking the time to post your results with the WattNode.