The GE Zenith GTX (sounds like an oil) uses a changeover switch. It eliminates two switching mechanisms (2 contactors) & replaces these with one switching mechanism. Of course, the switching mechanism would need to be rated to handle the "normal" supply characteristics.

My only concern is that the installation will still be connected to the "normal" supply until the generator is up to speed. If the "normal" supply should suffer any extreme variations while the generator is coming up to speed, the load will experience the variation/problem.

I think that disconnecting the load upon recognition of a problem (loss of phase, voltage variation, frequency variation etc) is paramount. I don't like the idea of a "changeover" switch being used.

The GE Zenith GTX (sounds like an oil) uses a changeover switch. It eliminates two switching mechanisms (2 contactors) & replaces these with one switching mechanism. Of course, the switching mechanism would need to be rated to handle the "normal" supply characteristics.

My only concern is that the installation will still be connected to the "normal" supply until the generator is up to speed. If the "normal" supply should suffer any extreme variations while the generator is coming up to speed, the load will experience the variation/problem.

I think that disconnecting the load upon recognition of a problem (loss of phase, voltage variation, frequency variation etc) is paramount. I don't like the idea of a "changeover" switch being used.

Hear, hear..! my electronic controllers will always drop out the mains contactor immediately upon phase failure or voltage/frequency variations (outside of parameters), very first action. With a classic ATS panel, I route the supply for the Mains contactor coil, through a normally open contact on the phase failure relay which has the same effect.

The GE Zenith GTX looks like a neat little package and I like the fact that these type of transfer switches can be manually operated as Crossy mentioned, but I'm not over the moon with the fact that it's not possible to completely break the connection to both supplies.