Do I need to change anything?

[Sparks]

Wonder if any experts out there could cast an eye on my electrical setup...

things I am unsure about are...

The size of the earth between the service head and the Henley block (6mm) (I cant change this, as it is obviously sealed into the head) Then the same to the split load consumer unit (again 6mm)

Does the generator setup look like it is compliant? (Especially the earthing sizes, and the SWA connected to free 32A plugs/sockets - Is that OK?)

What size earthing should be in place for bonding to the services, and where should the be connected (consumer unit, main Henley block, either?) Should the services (Water & Gas) both be connected back to the supply, or can they daisy chain with only one cable back to the supply?

Should the earth going to the transfer switch from the split CU really be taken to the Henley block?

The nutruel is tied to earth on the generator (well, in the free plug connected to the house) should this really be done in the generator?

When running from the generator, the earth (tied to the generator's neutral) is still connected to the grid provided earth (Armour of main cable) - is that OK (The transfer switch doesn't seem to have any provision to switch the earth as well as L & N)

When running from the grid, there is still an earthing rod connected to the earthing system as well as the grid provided earth - is this OK?

Thanks :-)

Sparks...

[Andy Wade]

Is it sealed? A PME earth is sealed (but wouldn't be 6 mm^2) but your picture seems to show a TN-S type supply cut-out where the earth connection is made by an external clamp onto the cable sheath.

Anyway all the earths in your diagram (except the generator cable) should be 16 mm^2, so you will have to find a way of changing it.

16 mm^2.

Several points here:

- have you consulted with the local mains supply DNO? You are supposed to "ascertain their requirements" and IME they like to approve standby generator installation arrangements. Their main concern is to avoid the risk of someone back-feeding the mains - there shouldn't be a problem in your case as you have a proper changeover switch.

- the earth from the genny frame to the electrode should be 16 mm^2 (unless protected in conduit);

- the bond between the genny's neutral and earth should be made in the generator, not at the junction box on the house wall (TN-S system). Your arrangement has a combined N & E conductor between the genny and the junction box, which isn't allowed. To be clear you should be bonding one end of the genny winding and its frame to earth at the genny. This defines the neutral point for your independent TN-S system. It may require some modification of the genny's internal wiring as portable gennies (like the picture) often have floating or centre-tapped-to-earth outputs;

- you should make your genny installation permanent by fixing the genset to a floor slab (or whatever) and get rid of the 32 A plug and socket arrangement. Failing that the 100 mA RCD in the transfer switch will need to be changed for a 30 mA type (see reg. 551-04-06, re. gensets that are "not permanently fixed");

- the 6 mm^2 cabling between genny and house is too small. You have a long run (26 m) and voltage drop would be excessive on 6 mm^2. I'd recommend 10 mm^2 minimum and preferably 16 mm^2 for this;

- is the 7.5 kVA genny capacity adequate to supply all your load? If not you are supposed to have automatic load shedding arrangements (see reg. 551-02-03);

10 mm^2, to the main earth terminal, which in your diagram is the terminal block just to the right of the supplier's cut-out.

Either way is acceptable. If daisy-chaining it's common practice to avoid cutting the conductor at the intermediate points. Just remove a length of insulation, form a U shape with the wire and insert into the earth clamp terminal.

Absolutely yes, to avoid any confusion over which is the main earth terminal.

Yes, that's OK, the earths are in parallel but if the mains cable is completely severed your independent system still has its own earth.