NEMA 14-50 Pass-Through Meter

WonkoTheSane

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#1
Am I crazy, or shouldn't there be a pass-through device I can plug into my NEMA 14-50, then plug a device into it, to see power throughput? Clearly I have no understanding of electricity or wiring or any of that.

I don't want to replace my NEMA 14-50 with an OpenEVSE or other charger.

I understand that I can get power information from my Model 3 but I thought such a simple device would exist.
 

WonkoTheSane

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#3
Yeah, I looked at options which is why I specified "pass-through". If it is too involved I'll just rely on Tezlab or Telsafi or something like that.
 

JWardell

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#5
You could probably build your own DIY one with $75 in parts, the real question is what do you want it for?
 

Ed Woodrick

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#6
240 volts @ 40 amps is not something that Walmart tends to have on their shelves. You may find one, but it's probably not going to be a cute little display, more like something a cubic foot in size. It's not something that many people would ever use.
 
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#7
Okay, this is what I use connected to my 14-50, it's less than $20.

Voltage/Current meter

I installed my own sub panel to house the breaker dedicated to charging the Tesla, also moved 3 other breakers from the main panel to make more room there.

The meter accumulates the kilowatt used and I reset every end of month. Simple division gets you the average for the month. Check the diagram for the meter for wiring. Simple and effective.
 

Avid

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#10
This is the one I have,

DROK


I like it better than the monochrome LED display and the kwh can be reset, I reset mine once a month.
 

ATechGuy

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#12
Okay, this is what I use connected to my 14-50, it's less than $20.

Voltage/Current meter

I installed my own sub panel to house the breaker dedicated to charging the Tesla, also moved 3 other breakers from the main panel to make more room there.

The meter accumulates the kilowatt used and I reset every end of month. Simple division gets you the average for the month. Check the diagram for the meter for wiring. Simple and effective.
Amazon description says 50hz, not 60?
 

garsh

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#13
Amazon description says 50hz, not 60?
Note: this meter is only used for measure 50Hz city electricity, it will be destroyed if used to measure square wave, output of inverter and modified sine wave circuit.

I don't think that "50Hz" is the important part here. They're saying that it's only guaranteed to work with a fairly clean sine wave.

Yeah, it's just a typo. Here's their website:

Digital Tester 4in1 AC Voltmeter/Ammeter/Power Meter/Energy Meter Multifunction Monitor Panel Meter/Digital Multimeter + Current Transformer

The multimeter can only work on AC 50-60Hz pure mains supply. Do not use it to measure square wave, inverter output and the corrected sine waves circuits, otherwise the product will burn!