Changeover switches reccomendations (and what do the regs say)

[jimseng]

Hello.
My electrician was questioning the regs regarding changeover switches as he has not fitted one to an inverter before. I intend to have two changeover switches, one to connect my grid DB to the load output of the inverter in the case of a long term power cut and one to connect the load DB to the grid in case of an inverter failure. I know others on here have done exactly this so I thought I would ask for recommendations as to what make/model of switch people feel is suitable. My inverter is a 10k single phase and the supply breakers will most likely be rated at 63 amp.

The electrician has always fitted large 3 position changeovers for large generator installations. His concern is whether there is a regulation that the changeover switch should have an off position, in other words a 3 position switch.

 
I was considering something that would be along the lines of the image below, din mounted in a neat box. rated at 125a. However this unit is £17 + vat which he thought sounded cheap and nasty.
It also seems to be a one or other position, not and on - off -on. Does anybody know if there is any reg or code of practice that prohibits this type of changeover for what I want to do?

Any particular units I should be looking at?

 

[JohnMo]

42 minutes ago, jimseng said:

output of the inverter

So is this an inverter that will run in Island mode, most don't 

[jimseng]

2 hours ago, JohnMo said:

So is this an inverter that will run in Island mode, most don't 

Yes. (It already is, not going to be on grid for half a year)

[Dillsue]

I've got 2 of those changeover switches, one in each of the main house consumer units. They let either of the CUs be fed from the grid or the backup output from the inverter. One is normally fed from the grid, the other normally fed from the inverter backup output.

 

I'm not aware of any regs that prevent that configuration but it's such a niche that I'm not sure those producing the regs will have detailed if and how they should be use?? 

[jimseng]

 

This Geya unit seems to be a 3 position switch. They seem very little money. Anyone got anything to say about quality or UK standards?

GYHO8 Transfer Switch 1P