Lights blink when AC compressor kicks in

[AraiHawk]

Hello all
I am new here and I have been reading threads in this forum for sometime searching for someone who has the same problem as me but couldn't find a related post.

So the problem is when the AC is turned on and the compressor kicks the lights dim for a split second ( fluorescent, and incandescent bulbs) only LEDs don't show the same effect, my neighbor is also facing the same problem and it happens on all three phases with different ACs old and new and different manufacturers, the problem also happens when I turn on the Vacuum cleaner.

one more thing, I noticed this happening only in the last three years and its been getting worse and worse to the point sometimes incandescent bulbs lose more than 50% brightness.

if anyone has any idea as to why this is happening please let me know.

a video showing what the problem is:
VIDEO-2018-06-26-19-36-42.mp4 - https://drive.google.com/open?id=1Ej1Lz6B45uA7GpU4V6AlfA_wmaamfWwP

 

[telectrix]

usually a voltage dip when loads with high start-up currents are switched on. could be a supply problem, or a poor connection at your installation source (live side of fuses/breakers).

 

[Pete999]

Voltage drop throughout the Electrical installation, added any new equipment/outlets over the years, maybe you need an electrical Power survey done to see what the loading is like, ie are the three phases equally loaded etc.

 

[Strima]

As above get your installation checked out. When was your last periodic inspection done?

As things are getting worse I would be leaning towards a loose connection on, or near, your source of supply.

 

[AraiHawk]

Thank you for all the replies,
the electrical load is balanced between all three phases and the last check was done in 2016. as I said earlier my neighbors are experiencing the same thing and I have another house in another city and it does not have this problem.

I made the electrician inspect for loose neutral wires and the three DBs I have one for each floor and a third for the outside kitchen.

at this point I am scratching my head cause I already called the electricity company and they checked the cables coming to my house from the poles for any loose connections and they were fine!!!!
I have searched the internet up and down left and right and done every single thing to fix it but with no luck I also got the capacitors in the ACs checked and they were all fine...

 

[telectrix]

if you neighbours are getting the same problem, it's deffo a supply fault. it could be that some industrial unit has recently been built/altered in the neigbourhood and is dragging the supply voltage down.

 

[Pete999]

How were the 3 phases checked load wise? you need a supply analyser fitted for a week or 2 to get the issue sorted, think you are wasting your time and money without getting a survey on your supply done first Mate.
You say the 3 phase are loaded OK how did you manage this?

 

[marconi]

Is your AC the type were the compressor and its fan are either running or off? Or is it a newer inverter type for which compressor and the fan can run over a range of speeds? If you provide me with the make and model number and can google for myself and answer the question.

 

[AraiHawk]

sorry for the really late reply


@Pete999 the three phases were divided across the rooms in the house and the halls and they were not checked with a supply analyzer.

@marconi I have both types Inverter ones and the normal ones and both have the same effect on lights upon first startup but then only normal ACs resume affecting the lighting whenever the compressor shuts off and comes back on.

 

[Pete999]

Are your A/Cs A mixture of 3 and single phase units? really does look as you either have some loose terminations somewhere, or an unbalanced poly phase installation, causing some voltage drop, it would pay you to get load readings on the system.

 

[marconi]

I concur with Pete999. Until you employ an electrician to do some inspection and testing (including measurement and observation of voltages and currents as the ACs turn on and off) and report the results, all I can offer is theorising on possible causes. If you find that your wiring and supply are both in order then there might be the possibility of introducing some 'soft-start' technology into the supplies to the 'normal' compressors' motors - I can provide a company name that makes these but they are not cheap so its best that you arrange for the initial inspection and testing to be done first.

Is it troublesome at all times of the day or only/more noticeable during peak periods of electricity consumption?

 

[AraiHawk]

Thanks for the replies guys and for following up with me on this.

@marconi @Pete999 I will get an electrician soon to check everything, it happens all the time during peak or non peak hours it still happens.
funny enough I have been to a shop that is near my house and they sell vegetables which means they have a lot of ACs and fridges running once one of the huge refrigerators kicked in the same thing happened so I am really just thinking about calling the electricity company and an independent electrician just to check everything, I am 100% sure now its a problem somewhere in the electricity lines and not in my house but there is no harm in checking my house too.


thanks for the replies guys I really appreciate all the help I got