Three Phase Change over switches any negative effects?

If we add 3 Phase Rotory Switches (3 nos) to change Phases ... Is there any adverse effects.

If we have a loose neutral or if neutral gets disconnect for some reason between the mains and having unbalanced load on phases will we have the chance for overvolting in any phase (440volts).

Will this happen only if i have the rotory phase shifting manual changer overs or will i be on the safer side if there is no change overs ?

Please help.....

What exactly is your problem? I presume your load is single phase and you have three phases at your disposal. With a rotary switch you can choose the best phase and connect your load to it.
Improper neutral is a problem in many places. If your load is single phase you MUST need good neutral.
If you are distributing your single phase loads on three phases perfect balancing is impossible. So, again you need good neautral other wise severe voltage imbalance may occur. Many people make a good earth connection and connect the neutral to this earth but it has its own problems.

I wonder why you chose this site for technical queries !

There is already a thread covering these devices. See Similar Threads in right hand column.

These things may be an Indian specialty.

Compared to UK, the only other country I have lived in, it is certainly an Indian speciality. three-phase cables run in the street, but single phases only are run to domestic properties. We never meet more than 240V in our homes, and even that can be nasty!
Given that it is a part of living in India, it is useful. I don't think that it is possible to get 440v on one phase, because each rotary switch selects which phase a given set of circuits draws from, and not which circuits are fed by a particular phase.

Thus, you can connect more than one circuit to a phase but not more than one phase to a circuit.

That is my ignorant and naive understand. If an electrical engineer can explain it in simple terms, then I hope they do. Especially if I'm wrong!

One risk that I do know about is overloading a single phase. EG: a house has three powerful AC machines, each of which is connected to a different phase; two phases fail, and all three AC machines are connected to the remaining phase. This could burning out of fuses, or even of supply cables (especially if the voltage is low).

I have wondered if this is a danger of automatic phase switchers?

Yes running all the gadgets on one phase in a house where wiring has been done assuming loads distributed on three phases poses danger. The neutral cable gets overheated along with the phase cable.

I assume OP has three-phase to house and three rotary switches to switch each in-house load ('phase') to one of three incoming phases. (Check other threads I've posted stuff about this before) - - - my engineer told me "they are illegal - you must have one".
In the few months since we finally got 3-phase we have either had 3 phases or none, but it's early days.
Will you unbalance the load fro the transformer? - yes; and if all your neighbours do it - YES; Will it increase the chance of everything dropping out? Yes
Do you care .....

AndyD 8-)#

During bouts of unreliable supply we quite often loose one or two phases for a while. We switch the three loads to the working phase[s]. But we discipline ourselves as to how much we use. I would not dream of turning three AC machines on one phase: if our supply cable burns out, it is a major expense and nuisance to us (Been there, got the tee shirt).

I'd like to have an auto phase switcher but if it turned everything to one phase when I was roasting a chicken with three ACs on, a load in the washing machine, the water pump on, the shower pressure pump running, something in the microwave, then the toast would not be the only thing burning