What should a Macerator be directly connected to , a Fused-Spur or the Consumer Unit ?

When working on a Macerator, do I disconnect at the Appliance or isolate at the Consumer Unit to ensure I am working safely ?

What should an instantaneous Hot Water Shower be directly connected to, a Fused Spur or the Consumer Unit ?

Appliances larger than the 30 amp Ring Main should be connected directly to the Consumer Unit.

See:
http://www.diydata.com/planning/ring_main/ring_main.php

Isn't the reason for requiring a disconnect at the appliance to ensure the safety of service personnel? A distant disconnect can be tagged and locked, but in addition anybody messing with one in sight can be thwacked up the side of the head with a large spanner.

Labman, look at the High Power Circuit paragraph, each appliance connected to the Consumer unit will be using it's own socket, which will serve as the service disconnect.

This "Ring Main" system is used in the UK and possibly other European countries, and is relatively new concept. Pretty interesting system.