Ongoing problem with flickering lights

[tunes]

Hi Guys,

I have an update regarding my flashing lights. I had an engineer at my home that measured the current in both lights fixtures and wall sockets with several equipment including a digital real-time oscilloscope. He came to the conclusion that the flickering is caused by the ripple frequency the power utility sends out in the area. I also went and chatted to some street neighbours and many of them experience the same flashing. It seems the ripple frequency affects all dimmers which are sensitive and thus causing the lights to flicker. I was delighted to hear that the issues is not in my house as most of you already suspected. The question is how would I bypass or get council to assist me in this matter? I have no ripple relays in my home - I'm guessing the power utility still uses ripple signalling in the area which causes harmonics in our homes. Could anyone advise what I could do? The ripple comes through in all three phases. I glad we've found the cause but the question is how do we solve it?

[SeanM]

Hi Tunes

Thank you for the update, it is always a pleasure to hear the final outcome.I know you send that when the voltage was stepped up the lights did not flicker, so in effect the ripple goes away when the voltage is raised.

[tunes]

Hi SeamM

It seemed to go away, or at least it helped but I think they tapped it back down at some point and as some of you have said that increasing or tapping up of the transformer may cause the voltage to go too high (which was not the case - it only went up to 238V from 220V) . The ripple signalling from CityPower will still be there regardless, which is what is causing the harmonics in the network and to sensitive equipment like trailing edge dimmers.

Ive read about low pass filters etc to cancel out ripple signalling to your home but not sure if CityPower would assist me and how I would go about for them to sort this issues out? I've spent thousands on new electrical switches, new cabling, new three phase and cables, new plugs, new bulbs, new dimmers and all new plug sockets - all as suggested by CitiPower because they had always said that there is no issue on their side and it could only be in the house - yet after undergoing all these expenses to find out that their ripple signalling is the cause, its rather frustrating and disappointing! They could have at least told me that ripple signalling/frequency was the cause but either they were too incompetent to tell me or had no idea that this is the cause. Either way I'm not sure where to go from here and how CityPower will assist me to filter or avoid their ripple signalling?

[Justloadit]

Maybe install a isolating transformer for lights circuits only, this may act as a filter.

[AndyD]

Alternative to Justloadit's suggestion is fit a ferroresonant UPS just for the light circuits. It would possibly give better filtering and voltage stability with the added bonus of it being a pre-made unit off the shelf and it will give you some back-up time in the case of power fail. If you're already using LED's the load should be relatively low so you'd only need a small UPS. https://www.powerman.co.za/online.html

[tunes]

Alternative to Justloadit's suggestion is fit a ferroresonant UPS just for the light circuits. It would possibly give better filtering and voltage stability with the added bonus of it being a pre-made unit off the shelf and it will give you some back-up time in the case of power fail. If you're already using LED's the load should be relatively low so you'd only need a small UPS. https://www.powerman.co.za/online.html

Thanks guys - will revert back when I've found a solution that works. I'm first going to try to get CityPower to install ripple signal filters (i think they'll have to do multiple filters on all three phases depending on the noise) I'm assuming the filters are installed outside on my main feed box? I also think a pure sine UPS dedicated for the light circuit would do the trick.

[Andreviljoen]

Hi. Sounds very much like a ''floating neutral'' to me.

[SiyaM]

Morning Tunes
I am a bit confused here. My understanding tells me the ripple voltage exist on DC systems that originate from AC sytems.
We are are talking about the AC system single phase 230 Volts RMS thats what munic is supposed to supply you. The voltage can flactuate due to veriuos reasons such as: floating neutral which is an earth fault. Overloaded trfrs, overloaded Lv networks etc the list goes on
I have neverseen any frequency controlling divices that are are installed on Lv reticulation systems to enforce a pure sine wave. Eskom generate transmit and distribute 50Hz with no filtering in between.

Either way your problem needs to be investgated by the supplier.

[Ridge]

Hi all,

I had similar problems with Shuttle LED dimmers. A hotel were we installed shuttle dimmers does a generator test every month. After every test some Shuttle dimmers went wrong and started flickering. Initially we thought it to be the generator output voltage or shape. However after the load shedding last month we notice the same problem.

Everytime we had to go back to setup some of them.
Now it turned out that the Shuttle dimmer tend to loose its memory settings after a power disruption which causing it to go haywire. In the end I had to replace all of them with Bikkel dimmers just to be safe. The Bikkel does not have this problem and are cheaper anyway.

What is disappointing is that they must be aware of this problem at Shuttle but I do not see any announcement made by them. To proper thing to do is to recall such product. Now it is up to us electricians to sort out their crab. If I knew beforehand I would have replaced them all the first time. Now I went back the fifth time to replace them all as you can not trust them and basically you sit on a timebomb going off after the next load shedding. After the load shedding other clients were I installed Shuttle dimmers complained about the same problem. I guess I have to face this problem till all are exchanged.