Are residential electric meters usable for DC, or just AC?

showme
showme Registered Users Posts: 94 ✭✭
edited April 2022 in Solar Beginners Corner #1

As I get ready to install my power panel to my two arrays, I've bought a standard GE house type electrical meter to keep track of what the arrays are putting out. Now I'm wondering if there is a certain type for DC generation, or if the one that I have will work to monitor what's being produced. I don't have it with me (in storage for now) for information, but it's a traditional analog that's been refurbished. The idea of the incoming power to the charge controllers and inverter is DC and might need a specific meter had not occurred to me until now. I can always use it on the exit of the inverter and see what I've used, but I'd like to see the "gross" input coming into the system without all the variable resistance factors and loss encountered from the equipment after the combiner box and wire run to the MS 150's.

Thanks for educating me on these meters in advance! Lee

"Knowing is not enough, we must apply. Willing is not enough, we must do."   Goethe

2006 Trace Xantrex power panel, (3) SW5548 inverters- 2 NOS Trace's (1999) and 1 Trace/Xantrex 2006 for back up (came with power panel. et al), Xantrex DC/disconnect, Xantrex AC disconnect/bypass, (3) C40 PWM charge controllers- 2 NOS, one used. (8)Evergreen  Solar 120w (960w),  8k LG Neon 2, (25) 320w, Bergey XL.1 1.5k genny, Air X 400 genny (came with used system), 48v Interstate Workman batts (now frozen/toast), (2) Montana Solar adjustable Top of Pole 12 array racks, (2) Midnite Solar MSPV 4 combiner boxes, (2) Midnite Solar Classic 150's (one an SL), SOK LiFePo stack of 500ah and one nice Ozark hilltop to set them all on.


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Comments

  • BB.
    BB. Super Moderators, Administrators Posts: 33,634 admin
    #2
    Standard mechanical utility meters are simply an AC motor that turns (RPM/actual turns) to record the power you are using. They will not work with DC power from the panels.

    I don't know about the electronic meters--But I would not bet that it will work correctly... Most assume AC coupling (current transformers, captive coupling, etc.) and need some sort of incoming power to run the electronics.

    There are lots of DC power meters out there on Amazon (as an example) that are cheap and can work in the 100-300 VDC range (just a quick scan of items):

    https://www.amazon.com/s?k=dc+power+meter&crid=1NP3I125Z4PD6&sprefix=dc+power+meter

    I would look at one of these first. Many seem to be $30 or less.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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  • showme
    showme Registered Users Posts: 94 ✭✭
    #3
    Thanks, Bill. After doing some searching for DC meters, I'm surprised I never thought about this before (residential meters are AC, always). I did find some actual analog DC meters that are built like the standard house meter, but they're pretty high priced for a tool just to see what the arrays are producing. After checking out all the smaller DC meters, I can see how they would be better, since they record and document the array production, as opposed to just showing what's been used to a certain point. I'll just use the one I bought to show what's coming out of the inverter instead. Thanks, and sorry it took so long to reply. Lee

    "Knowing is not enough, we must apply. Willing is not enough, we must do."   Goethe

    2006 Trace Xantrex power panel, (3) SW5548 inverters- 2 NOS Trace's (1999) and 1 Trace/Xantrex 2006 for back up (came with power panel. et al), Xantrex DC/disconnect, Xantrex AC disconnect/bypass, (3) C40 PWM charge controllers- 2 NOS, one used. (8)Evergreen  Solar 120w (960w),  8k LG Neon 2, (25) 320w, Bergey XL.1 1.5k genny, Air X 400 genny (came with used system), 48v Interstate Workman batts (now frozen/toast), (2) Montana Solar adjustable Top of Pole 12 array racks, (2) Midnite Solar MSPV 4 combiner boxes, (2) Midnite Solar Classic 150's (one an SL), SOK LiFePo stack of 500ah and one nice Ozark hilltop to set them all on.


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  • BB.
    BB. Super Moderators, Administrators Posts: 33,634 admin
    #4
    No problem Lee,

    Glad to be of help!

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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