TV Fluctuation

Connect them all to a UPS supply....

Mains filter?

As an aside 245V seems a little high.

Why is 245V high? Most distribution transformers are 433/250V.

Of course we don't know where the OP is, but, here is a list of "standard" international mains voltages:-

https://en.wikipedia.org/wiki/Mains_electricity_by_country#Table_of_mains_voltages_and_frequencies

245V is almost certainly within the acceptable tolerance wherever he is.

In the UK we started on 240V then "bent" the tolerancing to comply with the European 230V standard. Other countries started on 220V and went the other way.

250V is the voltage "at the pole" assuming that the 11000V supply is still 11000V when it gets there.

Your power is dirty.

See #1 and #2 above.

What do you mean by "fluctuation"??

What television transmission standard applies for these TVs?

I have known a cyclic change of picture proportions on cathode ray tube monitors due to magnetic field of overhead fluorescent tube lighting - no experience with LCD, but lighting tubes also project high electrostatic field. The cure was to move monitors away from under lighting

Have you tried turning all the lighting off??

Display is Flickering , I hope you understand now

OK, it is flickering. My guess is that this means you are missing complete frames of picture.

1. Are the "flickers" at exactly the same moment on all TVs?
2. Any difference between TVs on different supply phases?

I ask about TV standard because television picture frame rate used to be locked to the national mains supply frequency, which can vary significantly e.g. 48 - 52 Hz. Earlier analog TVs had significant ripple on rectified DC supplies, which could distort the scanning - a frequency difference between mains ripple and scan rate could cause a cyclic distortion at the frequency difference between mains and studio scan rate which was annoying.

However, less ripple on TV internal supplies meant studio scan rate was locked to 50.00 Hz eventually. Also, later analog TV systems had really good horizontal and vertical synchronising lock which could hold on weak, noisy signals.

If you have a digital system, a mains spike at a particular "point in wave" could periodically coincide with a critical moment in the picture at the "beat rate" between mains and frame frequency.

Since you write that mains is 245V, I do not think that break-though of ripple onto TVs DC supplies due to low voltage input to internal stabilizers is happening. Also the voltage "earth to neutral" is not significant - it is just the voltage drop in the neutral wire.

But I do not understand the point in the original post where disconnecting the input to one DB [Distribution Board??] increased neutral-earth voltage to 5.1V.

An inverter supply is probably closer to 50.00 Hz than your mains supply, it may be your problem is a significant difference between mains frequency and scan rate.

3. Do you know how much your mains frequency varies?

4. Is your flicker problem "all the time" or worse at some times of day?

It may be the inverter supply is removing/avoiding some regular interference burst on the mains supply.

5. Does the number of TVs connected make any difference?

6. Are all these TVs fed from one antenna through a distribution amplifier which could be a common factor, also moved to the inverter supply along with the TVs??

67model