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Posted By Topic: Voltage & Current Data Logger

John W
Apr 10 2013 19:46

Ive a case, where occasionally, the VSD will trip off on Overload, but as its in a rarely visited Plant Room and parallel plant will take up the lost load, I need some sort of Current recording with a time stamp to see whats gong on.
No one knows what causing the O/load, it happens in the evening, when things are starting to wind down. So its a bit of a mystery on the cause.
We dont know what form the overload is, slowly increasing load or sudden increase of load.
As the motor draws 60amp per leg, its not the sort of thing you can simply replace with a bigger unit.

So, has anyone out there recorded current over time on a data logger and what sort of gear did you use?

Thank

   

Brian W
Apr 10 2013 21:05

Check out Tech Rentals (google it) for what you need. Truckloads cheaper than buying something you'll only use twice a year.
   

Query
Apr 11 2013 17:20

There are a range of clamp meters on Trade Me for $2-300 which have a min/max hold function, here's 2 examples.

http://www.trademe.co.nz/building-renovation/tools/hand-tools/measuring/auction-580066072.htm

http://www.trademe.co.nz/business-farming-industry/industrial/electrical-equipment/gauges-meters/auction-580644089.htm

You just need to review the Specs and ensure that you can leave it in the min/max mode for say 24hrs without it going to a battery save sleep mode.

I assume they tell you the time it has dropped out, so you don't need to know the precise time, just the max reading.

If you suspect different circuits you could buy 2-3 of them, put them on the suspect circuits then re-sell them for $50 less when the problem is solved..

I have a 3 phase, 11 channel data logging system, logs in 10msec cycles, but costs around $2,000
   

Query
Apr 11 2013 17:34

Sorry, didn't realise you needed a time stamp...

Check out some of the house type energy meters. I had one from Jaycar that you could put 3 sensors for 3 phase, only limitation was that it updated in 10-20sec intervals, but I think it did update with the max per phase figure.

You can download the data to a PC but some are slightly tricky and may need a USB to serial convertor lead..

http://www.trademe.co.nz/electronics-photography/other-electronics/other/auction-580562676.htm

   

Query
Apr 11 2013 17:37

This is the Jaycar type,

http://www.jaycar.co.nz/productView.asp?ID=MS6165&keywords=watt+meter&form=KEYWORD

You'll need 2 extra sensors... $70 each..?

Part number MS6165 from their home page if the link above doesn't work...

I can send you 2 sensors to loan for nothing for up to a month if you want....
   

Query
Apr 11 2013 17:44

Heck the pack of 2 extra sensors for 3 phase is only $38 for 2...

Cheap as chips..

Part number Jaycar MS6166
   

JohnB
Apr 12 2013 11:22

You want to simultaneously measure 3ph voltage and current.
Agree with Brian, Tech Rentals is your best bet. PM30 or PM40 power analysers are good.
They can be set up to trigger on an event and will show pre and post trip conditions.