measuring and recording voltage 6

[Lnofeisone]

Hi everyone,
Thank you in advance for reading this. We seem to have outages in our building due to construction next door and number of people in my group run experiments overnight. Outage renders these experiments useless (if the outage is longer than 1 minute). Equipment doesn't report loss of power, it just restarts.

My simplest $10 solution was to buy an alarm clock that has no batteries. It'll blink if there is a power outage but it won't give me the duration of the outage.

I looked around online and found a bunch of voltmeters that measure voltage and log it. I just can't believe that $700 is the cheapest one around. I mean all I need is basically a voltmeter and a PIC to log the data. I'm wondering if there are cheaper solutions out there. If so, I'd appreciate the direction.

Thank you in advance,

Aleks

 

[dpc]

There are a lot of units like this that might work for you:

http://www.safehomeproducts.com/shp...zer-extra-storage/power-meters/1527/1527.aspx

 

[oldfieldguy]

Set your clock to the same time as your watch. If the power goes out and comes back on, your clock will be slower the next morning by the total time of the outage. It's a gross measurement. There are dozens of recorders that will do the job better, many of them below $500.

old field guy

 

[WhiteyWhitey]

We used to use some of the functions in a Digital 3 Phase meter to do this sort of thing.

The meters from a company here in Brisbane Aus (PM me if required) have an output relay contact that can be programmed to close on loss of volts.

Connected up to a GSM unit (Mobile network Modem) you can have the meter send you an sms message on events like this.

Its a bit of a gold plated solution to your partticular problem. However your meter may already have a loss of power alarm built in somewhere. Worth having a look.

Let me know if you want details on the equipment we used for the power monitor described above.

Thanks,
Andrew

 

[rbulsara]

Not sure how much is the load, but investing in a backup power for a few minutes would be much more beneficial than logging outages.

Rafiq Bulsara

http://www.srengineersct.com

 

[catserveng]

I use the Fluke VR101 for simple checks to start out, ebay has a couple for under $250. Easy to use, simple reports, and gets you started.

Although depending on the size of the experiments, if it really is critical as pointed out above a UPS is a good idea.

 

[itsmoked]

I'm with Rafiq. Just buy desktop UPSs for the experiments. Than you don't need to worry about the brief dropouts. If you want to spend a little more than the typical hundred dollar UPS you can get ones that log the details of any outages.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[Lnofeisone]

Thank you all for responding. Unfortunately a simple UPS won't be sufficient since the equipment draws approximately 50A worth of current and it runs on 208V. I'm gonna try the alarm clock approach first. It's cheap and quick. I'll simulate the outage . If not, $250 seems a lot better than the voltage loggers I found at $700+.

Thank you all for such timely responses!

Aleks

 

[waross]

Check the clock in the store before buying. Some clocks just flash after a power failure but many restart when the power is restored. We had a power failure early this morning and most of the clocks are flashing 1:26 indicating that the power was restored at 4:21 AM. No indication as to the length of the outage.


Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[Compositepro]

Use a clock with an analog display so the time does not reset on power failure. The kind with the synchronous motor would work well.