[PLUG-TALK] Emporia VUE - Capability and Goals

[Keith Lofstrom]

I am slowly learning about the Emporia VUE 3 measurement
capabilities.  Mostly, the 44 byte data packets that the
VUE transmits to Emporia, so that I can intercept, store,
and interpret those packets on my own server, and optimize
my generator use during a power outage.  I'd rather not
reflash and possibly brick the VUE.

I mentioned 50KW in the MEASUREMENT context.  That is NOT
what I need for a generator; it is the MAXIMUM RANGE OF
THE DATA that the Emporia measures (as integers) and
stuffs into that 44 byte packet. 

A decent description of those packets here:
https://flaviutamas.com/2021/reversing-emporia-vue-2

The VUE current sensors for incoming power are 200 amps.
The mains voltage might range as high as 125-0-125 volts.
So, 250 center-tapped volts (which is what the Emporia
measures) times 200 amps (maximum for the mains sensors)
is 50 kW ... which I hope to NEVER measure and cannot
afford to pay for long term.

However, the current measurement INTEGERS in the data packet
are scaled to 200 amps, while my PEAK usage on ONE leg while
PGE-powered may be only 6KW at 120V, or 50 amps.  25% of the
range of the sensor, 25 percent of the maximum integer the
VUE emits to describe that, 4 times the relative digitization
noise.

(Decades ago, I designed 10 bit 100 megasample-per-second
digitizers, and helped write IEEE standards about such)

I won't energize most branches in an emergency; my desktop
machines and printers will go dark, just some laptops
connected to the internet through the Ziply fiber ONT.

My world-facing servers are Linux virtual machines located at
the Rimuhosting data center in Dallas Texas (with fail-over
to servers in Brisbane Australia).  In an extended emergency,
I can exchange emails directly through those servers. 

When I rewired the house before moving in, I added a sub-panel
in the garage and moved the "emergency" circuits to that.  
A physical lockout switch arrangement in the garage, so that
the generator and PGE cannot connect to the emergency circuits
at the same time.  All inspected in detail by a professional
electrician, and inspected too-briefly by the county inspector. 

I may repeat those $$$$ inspections when the VUE installation
is complete, the VUE wiring is neater and wrapped in plenum-
grade zip ties, and the "generator shed" is built.  

That may also be a good time to deploy a quarter acre of PV
in back; not very useful in winter, but better than mowing
a quarter acre of grass in summer.

-----

This house will have more owners after me.  I will also
"internet archive" the online "house manual" so that owner
N+3 can access it, long after my wife and I are pushing up
daisies, and idiot owner N+2 discarded the paper manual.  
When we sell and move to assisted living, I will make sure
that owner N+1 is NOT an idiot, and price accordingly.

My "engineer forebears" planned for the far future; when
they built Winchester cathedral, they planted the oaks that
would furnish the beams to repair it 500 years later. 
My "retirement day job" is writing about provisioning for
life on Earth 200 million years into the future, and Out
There for vastly longer.  I cannot predict future
technology, but math and physical law will always apply.

Preparing a 65 year old house for another 65 years of
owners and improvements is baby steps compared to that.
Sadly, many spendthrifts don't think beyond their next
paycheck, and how quickly they can spend it on junk.
Those clowns won't deserve a home like this will be.

Keith L.

-- 
Keith Lofstrom          keithl at keithl.com


-- 
Keith Lofstrom          keithl at keithl.com