Remote, wireless, mains voltage measurement/monitoring ?

Heater.

I need to measure the mains voltage arriving some equipment at the top of a tall pole/mast.

Turns out we cannot get access during the times when we want do the measurement.

So I though there must be some gizmo we can put on the line, at the top of the pole, to measure the mains voltage and transmit it to the ground wirelessly. WIFI range would do.

Ideally it would be something that could be put in place and used to log the voltage for a few days/weeks then be removed and used elsewhere.

So far, googling around, I have only come up with the CircuitSpy http://www.redbusbar.com/CircuitSpy.html

Anyone know of alternatives or have experience of such things?

Sapphire

How tall? How much load at the top? What wire size?

Why couldn't you run a separate pair back down and measure it there?

Heater.

Not terribly tall. A cheery picker can get a man up there.

Our load is only 20 watts or so. But power line is basically a drop from a circuit that powers a ton of LED lighting.

Not sure of the wire size. Not much bigger than domestic mains wiring.

Cannot run a drop down from there due to safety concerns, regulations, bureaucracy, da, da, da. It's almost impossible to get permission to do anything on that site.

I'd like to determine the stability or otherwise of that supply.

What I'd I really like to be able to measure is how much junk interference gets into that line from all that LED lighting.

pmrobert

The members at http://www.eng-tips.com/threadcategory.cfm?lev2=11 would likely have a device suggestion for you. There's one subforum in there that has decent threads on switching power supply and VFD harmonics, etc., on the line and suggestions on how to monitor it w/ logging device suggestions.

Heater.

pmroberts,

Thanks. Interesting, never heard of eng-tips before.

Do you have a direct link to such a forum. I'm not fining one yet.

pmrobert

Heater, eng-tips.com/ should get you to the home page. A site-wide search on "power data logger" returns 20 or so results with links to other threads. Combinations of "SMPS", "LED", "analyzer logger" also return a fair amount of recommendations (some chaff, of course). There are a lot of forums there but being engineers, it is well organized but easily drilled down (at least for me). You may need to make a login to use the search function, I don't recall as it was some years ago that I first started using that site. Their only restrictions to posting requests are basically no student questions and present your case as fully as possible when making a request. I'm thinking that if you posted your original request on "Electric power & transmission & distribution" under "Electrical / Electronic Engineers Area" you'd get some good info. They would likely want to know the voltage, Hz, other connected loads, current, # of LED lighting units and what kind, etc. I'm sure such a device you're searching for exists.

Heater.

OK. I'll give it a go.

jmg

Heater. wrote: »

What I'd I really like to be able to measure is how much junk interference gets into that line from all that LED lighting.

To what frequency ? You might want to change title, as it sounds like a simple Voltmeter is not quite what you want.

Heater. wrote: »

Cannot run a drop down from there due to safety concerns, regulations, bureaucracy, da, da, da. It's almost impossible to get permission to do anything on that site.

Not even a low voltage, isolated line ? ( eg I can see Photovoltaic Isolators, that can do 5300v RMS isolation ?)


On the wireless front, one low cost 'analog' wireless solution, would be to use the AC to drive a FM transmitter. You then receive that with a FM receiver, and process the spectrum to see 'how much junk interference' is there ?

Heater.

jmg,

Whilst I can arrange for a guy to go up in a cherry picker briefly and attach some measurement gadget, anything else, especially running any kind of cable will require negotiation, permitting etc. Could take months.

Frequency? No idea. I wish I could get up there myself with a scope and see for myself. Problem is I'm on the wrong side of the planet! I can't get a guy up there to do that because no access is allowed during the hours when the problem arises. Basically when all those LED lights come on, as far as I can tell from the data I am receiving/not receiving here from the device in question every day.

It's infuriating.

frank freedman

Heater, you don't give the voltages required, but with an appropriate divider etc, perhaps putting a Digilent Analog Discovery 2 and a small windows or Linux tablet up there with WiFi may be a possible way to do this. If you can power the setup from this same line, it could rem a in up as long as you need it to be. The AD2 can be used with its own waveforms software, or you could use the API and roll your own solution. Just an alternative idea.
There are also PowerLine monitoring systems we have used for years in the medical imaging field to chase down noise problems. Can't imagine there are no compact versions of these with some form of wireless communication and pretty deep logging including events and waveforms.

FF

Tim-M

Heater,

This is a good wireless off-the-shelf and reasonably priced option, with modules to measure all sorts of things...

https://www.monnit.com/

Tim

Heater.

@Frank,

Sorry, I should have said, it's good'ol American 110v mains. I'd love to put together a monitoring system as you describe. I don't have the time to do it. Shipping the thing there and explaining to anyone how to use it would also be a hassle. Hence my search for a plug'n'play solution.

@Tim-M,

Thanks for the monnit tip. This looks like it may be the thing: https://www.monnit.com/Product/MNS2-9-W1-VM-500

Tim-M

You're welcome Heater, lots of good options there.