Macerator spur from lighting circuit???

[Ian1981]

Yep, 100% it is on a 15amp fuse, earthing of lighting circuit is satisfactory, but am unsure why I need to upgrade bonding???

You don’t necessarily need to upgrade any protective bonding conductors , just need to verify they exist if required and are satisfactory.
If extraneous conductive parts exist within the installation and do not have any protective bonding conductors Connected to the MET then your work can not proceed.

 

[ruston]

To be fair there are regs in place for additions to existing circuits , if no rcd is in place the supplementary bonding can not be excluded.

 

[Deleted member 9648]

A lighting circuit on a 15a fuse would ring alarm bells for me. Particularly as from the questions the OP is asking I doubt he has the competence to verify a safe addition to an existing circuit.

 

[westward10]

Rewireable fuse or cartridge.

 

[The Ghost]

Can you not spur from the ring/radial circuit and put it on the other side of the wall of the bathroom? But 15a lighting circuit, never seen it, must get out more.

 

[Ian1981]

Only time I see 15amp lighting circuits are older commercial properties/factory units where the lights have been wired in pyro 1.5mm or 2.5mm for banks of fluorescent lighting.
Even then they are bs 3871 devices so 16amp.

 

[pirate]

Thinking vorti is being practical here. Even if dropping circuit into bathroom, feed it out to hall/bedroom and keep CU out of the bathroom, leaving you options for cabling under floor/bath/whatever?
I say this not as an expert, but I know my spa bath has a power supply from the loft, via an RCD in the bedroom cupboard, to a switched outlet and then through the bedroom wall, under the units to the bath motor, thus no connections in the bathroom at all, apart from the final ones at the motor...and the same for the electric shower. I bow my head to those who really know about these things, naturally...