Arduino Forum

Topics => Science and Measurement => Topic started by: femur on Sep 26, 2013, 05:24 pm

Title: Stray Voltage on Dairy Farms - Arduino
Post by: femur on Sep 26, 2013, 05:24 pm
Hello, i was wondering if anyone has experience of sensing stray voltage currents on farms with an Arduino,

Regards,

Femur
Title: Re: Stray Voltage on Dairy Farms - Arduino
Post by: CrossRoads on Sep 26, 2013, 07:34 pm
Stray voltage currents originating from what?
Title: Re: Stray Voltage on Dairy Farms - Arduino
Post by: AmbiLobe on Sep 27, 2013, 09:17 am
" i was wondering if anyone has experience of sensing stray voltage "

I measured an extension cord that was not plugged in. It had a voltage on a wire. Many volts AC were observed with a multimeter. It must be inductive coupling from nearby magnetic fields. Floating wires get stray voltages, low current.
Title: Re: Stray Voltage on Dairy Farms - Arduino
Post by: JChristensen on Sep 27, 2013, 01:55 pm

Stray voltage currents originating from what?


Usually from power transmission. Not an uncommon phenomenon.
http://en.wikipedia.org/wiki/Stray_voltage

Edit: Some general guidelines here: http://www.wisconsinpublicservice.com/business/farm_voltage_measuring.aspx

An Arduino should be able to take the place of the multimeter used to make measurements. Some additional input circuitry may well be required depending on the voltage level. Sounds like a good application for some data logging as well since a 24-48 hour measurement is preferred.
Title: Re: Stray Voltage on Dairy Farms - Arduino
Post by: femur on Sep 27, 2013, 05:08 pm
CrossRoads: Like they said, from power transmission. Mainly on the bailing and floors where cows are milked

Title: Re: Stray Voltage on Dairy Farms - Arduino
Post by: MarkT on Oct 03, 2013, 02:45 pm

Hello, i was wondering if anyone has experience of sensing stray voltage currents on farms with an Arduino,

Regards,

Femur


Why do you want to sense this?   And do you want to sense voltage or current?  Do
you want a device that will survive a thunderstorm (because once you start connecting
sensors to long cable runs in the outdoors you are asking for them to be zapped)?
Title: Re: Stray Voltage on Dairy Farms - Arduino
Post by: femur on Oct 06, 2013, 04:54 am
MarkT, i want to sense this because it is a major source of discomfort for the cattle, really upsets them making the life of the people working with them more difficult as a direct result.

http://milkquality.wisc.edu/wp-content/uploads/2011/09/short-duration-electrical-currents.pdf

I do want to sense voltage, the arduino is used just as a portable tester, no need to leave it on place

Title: Re: Stray Voltage on Dairy Farms - Arduino
Post by: CrossRoads on Oct 06, 2013, 05:09 am
Hmm, I don't know about sensing it.
Have you taken any steps to add grounding wires to short any stray voltages to ground?
Title: Re: Stray Voltage on Dairy Farms - Arduino
Post by: MarkT on Oct 06, 2013, 01:23 pm
Yes, the obvious issue is metal equipment that is not adequately (locally) grounded.

The cause of the voltage could be various things, but a faulty mains earthing system
is one possibility that is life-threatening so get an electrician to check that first.

Humans typically live in a dry environment and wear shoes/boots, so we wouldn't
notice a few volts between local ground and mains earth wire.

You want to eliminate the issue, not just measure it?  A multimeter on AC-volts
can measure it if you ground one probe, that's easy.

You need an closeby earthing spike driven into the ground (keep it watered in dry weather),
connect external metalwork and metal water pipes to the spikes (lookup local wiring
regulations or talk to an electrician first though).

Also avoid any equipment that isn't properly earthed.  In a harsh environment
regular electrical safety checks are obviously necessary...
Title: Re: Stray Voltage on Dairy Farms - Arduino
Post by: jremington on Oct 09, 2013, 05:32 am
I completely agree about the possible dangers associated with faulty mains grounds, once having gotten a serious shock when making a connection between two different ground wires at a water well. The problem was due to faulty ground wiring at the pole where the "service drop" comes into the house -- which in our vicinity is the responsibility of the power company. Have your wiring checked by a professional!