Install new consumer unit with conduit as earth for power circuits

[j s i]

Hi all,
I need to install a new consumer unit where the power circuit is using steel conduit as the cpc.
The conduit is bushed and terminated correctly at the socket back boxes and into the Mantel unit for the fuseboard.
Zs readings are all good at socket outlets.
There are no earth fly leads from the back boxes to the socket outlets, but 1 screw lug in each back box is fixed and 1 screw lug is adjustable.

As I haven't installed/altered the ring final circuits is it ok to connect the new consumer unit to existing circuits.

Thanks in advance.

 

[Engineer54]

Yes, all your doing is replacing/upgrading the installations circuits protection...

The conduit is fixed to the recessed Mantel box, you i take it, are fitting a replacement Skeleton dual RCD unit to replace the old Wylex 3036 unit, so you won't in essence be altering anything on the final circuit side of things....

 

[Deleted member 26818]

I would not be happy relying on the one fixed lug as a means of providing an earth connection to the socket-outlet.
Any accessory connected to the socket-outlet will be using the one fixed lug and screw as it's earth connection.
To my mind this scenario is one where a fly lead is required.
If you connect the CU without installing fly leads, you should make a note of the lack of fly leads under 'comments on the existing installation'.

 

[telectrix]

i'm with spin on this one. fit fly leads.

 

[j s i]

Thanks for the advice guys,

I will fit the fly leads as a good practice, seems the sensible thing to do.

 

[Engineer54]

Thanks for the advice guys,

I will fit the fly leads as a good practice, seems the sensible thing to do.

It is!! lol!!
While your at these boxes fitting the fly leads, give the conduit brass male bushes a turn to check the tightness too, only takes a minute or so...