We have moved at community.getvera.com

Author Topic: Voltmeter ? (grid Voltage)  (Read 5292 times)

Offline nullx8

  • Hero Member
  • *****
  • Posts: 870
  • Karma: +9/-3
  • Trouble !
Voltmeter ? (grid Voltage)
« on: May 20, 2014, 08:41:41 am »
does anyone have maybe a recomentation for a VoltMeter (30-250 Volts)
z-wave based or something else the vera can read ?
« Last Edit: May 21, 2014, 11:19:16 pm by nullx8 »
1 VeraLite, 2 RaspberryPI, Harmony Remote, openLuup, 85 Devices, 34Nodes, 63 Triggers, 49 Scenes

Offline garrettwp

  • Master Member
  • *******
  • Posts: 6371
  • Karma: +227/-128
  • Vera 3, Lite, ISY994
Re: Voltmeter ?
« Reply #1 on: May 20, 2014, 11:17:18 am »
You may have to look into the arduino route as I'm not aware of such a device for zwave.

- Garrett


Offline hek

  • Beta Testers
  • Hero Member
  • *****
  • Posts: 714
  • Karma: +60/-1

Offline garrettwp

  • Master Member
  • *******
  • Posts: 6371
  • Karma: +227/-128
  • Vera 3, Lite, ISY994
Re: Voltmeter ?
« Reply #3 on: May 20, 2014, 12:57:30 pm »
Good start, but that only supports up to 25 volts.

- Garrett


Offline akbooer

  • Beta Testers
  • Master Member
  • *****
  • Posts: 6387
  • Karma: +292/-70
  • "Less is more"
Re: Voltmeter ?
« Reply #4 on: May 20, 2014, 01:11:31 pm »
Good start, but that only supports up to 25 volts.

...can't help thinking that a simple resistor ladder would sort that?
3x Vera Lite-UI5/Edge-UI7, 25x Fibaro, 23x TKB, 9x MiniMote, 2x NorthQ Power, 2x Netatmo, 1x Foscam FI9831P, 9x Philips Hue,
Razberry, MySensors Arduino, HomeWave, AltUI, AltHue, DataYours, Grafana, openLuup, ZWay, ZeroBrane Studio.

Offline hek

  • Beta Testers
  • Hero Member
  • *****
  • Posts: 714
  • Karma: +60/-1
Re: Voltmeter ?
« Reply #5 on: May 20, 2014, 01:46:01 pm »
Good start, but that only supports up to 25 volts.

- Garrett

Opps, you shouldn't connect that to 250V!

Offline nullx8

  • Hero Member
  • *****
  • Posts: 870
  • Karma: +9/-3
  • Trouble !
Re: Voltmeter ?
« Reply #6 on: May 21, 2014, 12:02:07 am »
i want to messure the Grid-voltage even if the main breaker disconnected.
to have a way to know when the grid is back "solid" after a failure.

so the vera could make the switch back from emergency to grid power

audrino may be a way to do it, but out of experience, audrino's its not exactly very reliable if powered on instable sources.
 
1 VeraLite, 2 RaspberryPI, Harmony Remote, openLuup, 85 Devices, 34Nodes, 63 Triggers, 49 Scenes

Offline BulldogLowell

  • Hero Member
  • *****
  • Posts: 1576
  • Karma: +191/-85
Re: Voltmeter ?
« Reply #7 on: May 21, 2014, 09:28:28 am »
i want to messure the Grid-voltage even if the main breaker disconnected.
to have a way to know when the grid is back "solid" after a failure.

so the vera could make the switch back from emergency to grid power

audrino may be a way to do it, but out of experience, audrino's its not exactly very reliable if powered on instable sources.

putting the sensor upstream of the breaker, you are now in the electrical territory of the meter, no?  Is there a flashing LED or a spinning dial that you can 'sense'.

Isn't one way (and safer) to just put your vera/modem/router/switch onto a UPS and wait out the service interruption?  Besides, what can you control if there is no mains power?

Offline futzle

  • Beta Testers
  • Master Member
  • *****
  • Posts: 3260
  • Karma: +192/-9
Re: Voltmeter ?
« Reply #8 on: May 21, 2014, 06:48:00 pm »
Besides, what can you control if there is no mains power?

I get the feeling that nullx8 has a generator or batteries that kick in when the grid power is off.  nullx8, care to elaborate?  Don't be afraid to write a lot of text.

Perhaps another approach is in order.  How do you currently tell that grid power is back?  Does your backup power source know?  Can you get Vera to monitor the backup power source instead?  (I'm trying to hedge my words in more general terms than BulldogLowell but we're sort of talking about the same thing.)

Offline nullx8

  • Hero Member
  • *****
  • Posts: 870
  • Karma: +9/-3
  • Trouble !
Re: Voltmeter ?
« Reply #9 on: May 21, 2014, 08:32:55 pm »
sorry for the confusion..

i have all my routers, switches accesspoints vera and whatnot connected to power via a Computer power suply, which is served via a 500watt UPS .. so the vera stays on if the power is out.

on the Generator i installed a 1/4" Magnetic solenoid valve on the gasoline line which is also controlled by the same power source. the Rasperry PiFace board relais does control the Solenoid ... (small pyton app make sure the vera knows the status and can control it (i do control the same type solenoids (just larger ones) to water the plants outside in the same fashion .. so this is pretty much failsafe)

i also use a 220 Volt Relais to actually start the Generator (integrated the same way as the solenoids)

the generator output is hardwired to the Breaker box .. i put a large Industry Relais (120 Amps) before the Main Breaker (of course there is another "main" before that now)
which simply switch between the Grid and the Generator Power ..
the large relais is powered by the power coming from the generator .. so if everything is in idle .. the relais has no power and the Grid serves everything. very straight forward.

all this works great so far. (its not really rocket sience) ;)

the problem is that i have no way on "automatically" start the generator,
the vera does right now open the gasoline valve and actually start the generator .. (so i can do this while sitting on the sofa)
since the switching is hardwired there is no room for misstakes.

but i have to trigger it by myself.

How do you currently tell that grid power is back?  ...

i dont ! and that is the problem !

on daytime: what i do now is connect a Digital voltmeter .. to see the power is back up (since many times the grid voltage remains at 80 volts or so for hours)
in the night i just check the house across the street which is served by the same phase .. if the TV running there .. i switch back.

so there is currently NO way to safely assume the power has been restored, and i would really like to have this more automated, as i just can't expect my wife or the in-laws to do this kind of verifications.

with the vera controlling the gasoline pipe and the Starting of the generator itself .. my wife can just start the backup power process via the touchscreen on the wall ...
but there is just no way for anyone other than than me to get the grid back online.

while doing this aproach, having the right parts in place, automating this completly is just a few little steps away.

by simply monitor the Grid Voltage and make the values avaiable to the vera.
so a simple scene could start the generator (or at least send me a message that the power is out)
and if the grid voltage is stable for some given time the vera could just shut down the generator and everything would get back to normal.

well thats the idea so far ;)
1 VeraLite, 2 RaspberryPI, Harmony Remote, openLuup, 85 Devices, 34Nodes, 63 Triggers, 49 Scenes

Offline BulldogLowell

  • Hero Member
  • *****
  • Posts: 1576
  • Karma: +191/-85
Re: Voltmeter ?
« Reply #10 on: May 21, 2014, 09:10:18 pm »
hmmm...  Our whole home generator (propane fired) has an automatic transfer switch.

Power out? generator on.  Power back? generator off.

I can't remember but it seems like that part cost just a few hundred dollars.  If service power is lost, it equates to a short interruption (just a few seconds) for those circuits that are serviced by it, and there is nothing to be done manually.

One thing I cannot understand is why you would need to have a valve on the fuel supply.  Doesn't the generator have an integral fuel pump?

Because of its reliability (I am actually dealing with that at the moment) I worry having Vera even control my lawn sprinklers.

Gasoline valves, generators, wives and Vera would most certainly be a dubious mixture in my home. ;)

Offline futzle

  • Beta Testers
  • Master Member
  • *****
  • Posts: 3260
  • Karma: +192/-9
Re: Voltmeter ?
« Reply #11 on: May 21, 2014, 09:41:20 pm »
Thanks nullx8 for the extra detail.  Here's a couple of ideas for you to consider.

Z-Wave voltmeters are rare, but current meters are plentiful. Aeon Labs makes one that uses a clamp around the active line of your power supply. It's a bit inaccurate but it might be sufficient for your needs. You just need to have it sufficiently upstream that it can't be powered by your generator. Perhaps just a 10 W light bulb or something as the load.

Or you could have the grid supply power to a Wi-Fi router that broadcasts a signal while there is grid power. You could then use something like the Ping Sensor plugin to tell when the signal is "home".

The trick is to make sure that the generator cannot push current back upstream onto the grid. You need special hardware for that. Contrast with my home where I have solar panels and I _want_ to push power back onto the grid because I am paid for it.

Offline SteveZ

  • Sr. Member
  • ****
  • Posts: 328
  • Karma: +4/-1
Re: Voltmeter ?
« Reply #12 on: May 21, 2014, 09:50:34 pm »
How about something like this, then just hook the contacts up to a z wave door window sensor.

Offline nullx8

  • Hero Member
  • *****
  • Posts: 870
  • Karma: +9/-3
  • Trouble !
Re: Voltmeter ?
« Reply #13 on: May 21, 2014, 11:09:39 pm »
pushing back to the grid is technically impossible, as the "switch" is made by a large Industry Relais .. directly powered by the Generator itself.
it has NC and NO Contacts ... where NC is the Grid and NO is the Generator.

so there is physically no way generated power gets in to the grid. its either grid or gasoline ...

the Magnetic valve thing has 2 reasons.
1. its a 400USD generator with a well soso-engine .. to prevent the gasoline getting out and providing some extra security i did install this.
also i (can) use this valve to Shut down the motor as well. planning on upgrading to a diesel Engine where i can't just turn off the ignition.
also it makes me feel safer and the magnetic valve itself just costs 4USD ;)

currently the ignition and the valve are on the same relais .. so if the ignition is on the valve is open ..
its just double security.

mainly just to make me feel better, since the generator is "technically" inside the house

some small room acessable only from the outside of the house for gardentools and I will not swear ...
there is the generator installed (perfect location since the vera is just 1 meter away on the inside and all cables for gardening, and the outdoor sensors go trough this room anyway)
i just made a small hole and a cover for the exorst trough the wall, and installed a window-fan on the access door .. to deliver Air faster ...
works on operation temperature even if it has to run 24 hours ..


« Last Edit: May 21, 2014, 11:27:51 pm by nullx8 »
1 VeraLite, 2 RaspberryPI, Harmony Remote, openLuup, 85 Devices, 34Nodes, 63 Triggers, 49 Scenes

Offline nullx8

  • Hero Member
  • *****
  • Posts: 870
  • Karma: +9/-3
  • Trouble !
Re: Voltmeter ?
« Reply #14 on: May 21, 2014, 11:13:44 pm »
How about something like this, then just hook the contacts up to a z wave door window sensor.

that is actually a great idea .. and alot more solid and it is self operating.
thats exactly what i need, a Door sensor will create a contact-less bridge to the z-wave network .. and all is set !

1 VeraLite, 2 RaspberryPI, Harmony Remote, openLuup, 85 Devices, 34Nodes, 63 Triggers, 49 Scenes