View Full Version : Voltage monitoring

15-07-2014, 03:48 PM
Hi All,

We are currently looking for some voltage monitoring/control equipment.
We are having issues with single phase systems tripping off/not starting etc when the voltage drops/spikes normally because the system is in a poor supply area.

Apparently OMRON do a NO/NC relay which will monitor the voltage on a adjustable +/ % and switch accordingly, with an adjustable timer before the relay makes.

So voltage drops by 10% relay opens unit turns off
Voltage recovers, relay waits 2 mins
Relay makes, unit turns on

Anybody have any ideas of where we can get hold of these?

The Viking
15-07-2014, 05:04 PM
You mean something like THIS (http://uk.rs-online.com/web/p/monitoring-relays/3611619)?

That would be RS components then.


18-07-2014, 09:31 PM
hi, I use a model of Tele-Hasse, http://www.tele-online.com/en/, I use a model with control of overvoltage, undervoltage, delay to switch-off, and, eventually, phase failure and sequence. And you can select which function to use (under, window, window + seq).

21-07-2014, 02:17 AM
Have you considered using a UPS system?

If the brown outs and total failures are causing nuisance then this is what you need to be looking at as an improvement.

21-07-2014, 06:37 AM
Hi Jdunc.
I have used hi and low voltage protection, but not reset function that would be dangerous. perhaps power factor correction balance would smooth spikes at primary source input to site, add a UPS on control system.

21-07-2014, 01:26 PM
It will switching low voltage, not option for UPS domestic property. The unit only suffers maybe once or twice a year, normally just a power cut, never over voltage.

Some fuddy duddy house in the middle of a forest park

21-07-2014, 02:12 PM
UPS systems are generally used on low voltage, I have built an offline one for my uncles farm out of some old boat/marine batteries, and LC bridge network, some old re conned alternators driven from a water spring.

Also there is a an old repaired cycle convertor with a flywheel and we are considering setting in up on a load sharing circuit. Its a Heath Robinson to say the least, but it works and was cheaper than buying a taylored made fully online one that come with a 10 kva generator that some specialist said he would need as a bare minimum.

Is the building occupied, and does the unit need to auto reset?

He also suffers the same problems with brown and black outs, keeps his central heating, lights, and enough left over for a few socket outlets offering a low load.