Looking for simple way to switch which loads go through power meter

[scottsmithline]

Hello, I am building a simple small backyard solar system to power a small fridge, one or two small fountain pumps and some led lighting. I am starting the system as follows:
295 watt REC solar panel
100 Ah LiFePO
Victron Smart Solar charge controller (100/30 sized for expansion)
Victron Smart Shunt
Blue Sea fuse block
wiring, fuses, breakers etc. as necessary

I will be including my children in this build and one of the things that seems to interest them is being able to see real time indications of power usage. I am therefore planning to install a couple simple power meters after the fuse block to display the real time power consumption of the the various loads. Given the additional complexity and clutter on the power board, I was hoping to install only 2 meters and then be able to switch which loads are running through the meters at any given time.

Is there a simple way to wire this up? Any suggestions appreciated.

Thanks!

 

[scottsmithline]

Any suggestions would be appreciated.

Thanks.

 

[mmame]

So you want to run all that stuff in parallel but dynamically select which of the sinks are being metered, right?

 

[scottsmithline]

So you want to run all that stuff in parallel but dynamically select which of the sinks are being metered, right?

yes. correct.

 

[12VoltInstalls]

There’s a couple ways I can think to do that. Don’t know if there’s a retailed device to do that. But considering the cheapo inductive ‘monitors’ are so little money, I think a little operations monitoring center wouldn’t be that obtrusive

 

[scottsmithline]

There’s a couple ways I can think to do that. Don’t know if there’s a retailed device to do that. But considering the cheapo inductive ‘monitors’ are so little money, I think a little operations monitoring center wouldn’t be that obtrusive

Thanks. I am not sure exactly what you are suggesting. Is the operations monitoring center you are referring to a simple power meter for each load wired in parallel? I was hoping to avoid that in place of having one or maybe two, and be able to switch which loads are being monitored with a switch of some sort.

 

[12VoltInstalls]

You can do the switch thing, sure. But exactly what device will you utilize to measure the loads? You’ll have one readout/monitor meter, a bunch of momentary switches, and a dozen or so inductive pickups that the single monitor is compatible with?
bayite AC 80-260V 100A Digital Current Power https://www.amazon.com/dp/B00YY1KOH...abc_NKSA55N1VRZN28WBAN6C?_encoding=UTF8&psc=1

 

[scottsmithline]

I guess I was thinking of using a shunt based monitor. But it seems like all the circuits would need two (switchable) paths, one through the shunt and one that bypasses the shunt. If that is the case, perhaps it is just too complicated.

 

[Supervstech]

Side note here...
You say 100Ah battery. I am assuming 12V
The 100/30 charge controller is pretty maxed out at 300W... it doesn't leave much room for future expansion...

 

[scottsmithline]

Side note here...
You say 100Ah battery. I am assuming 12V
The 100/30 charge controller is pretty maxed out at 300W... it doesn't leave much room for future expansion...

Perhaps I am still not clear on the ratings. My REC 295w panels are rated at 39v and 10a. I thought I could add a second panel, either in series or parallel, and still be within the parameters of the SCC. Do I have this wrong?

 

[Supervstech]

SCC amperage is output amps, not input… so if you are feeding 295W solar input, and outputting 12volts to the battery, you are close to 30Amp limit of the solar charge controller.
If you up the voltage to 24V battery, you halve the amp load on the controller.

 

[scottsmithline]

SCC amperage is output amps, not input… so if you are feeding 295W solar input, and outputting 12volts to the battery, you are close to 30Amp limit of the solar charge controller.
If you up the voltage to 24V battery, you halve the amp load on the controller.

Da. Thanks. That totally makes sense. It is so easy to get ahead of yourself with this stuff. Thanks.

 

[mmame]

You could also use some split coil hall current sensors and just select the consumer(s) wire(s) you want to monitor. I.e. as seen here for AC applications: https://learn.openenergymonitor.org...ensors/interface-with-arduino?redirected=true

To further improve precision, the Voltage could be measured, too (which is obviously the same for all consumers).

 

[-sgt-]

Try to look up for smart switch with Sonoff POW R2 or Sonoff Dual R3, maybe my suggestion suits your need...