Thread: RCDs in series
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John Rumm John Rumm is offline
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Default RCDs in series

Doctor Drivel wrote:


Better fault tolerance,

= less safer.


No, it means it is less likely to pose a shock or fire risk in the
presence of the most common faults.


Nonsense.


I have already given you concrete technical reasons why shock and fire
risks are reduced for a number of common circuit faults; plus you have
had presented to you details of why our circuit designs result in fewer
trip and fall injuries. Hence you will need to counter with
significantly more effort and reasoning in your reply than that.

Average kitchen: Washing Machine, Dish Washer, Toaster, Kettle,
Microwave etc. That alone could be pushing 11kW. Now what was the
nonsense you spouted again?


On a radial, Washing Machine & Dish Washer will have their own MCB at
the CU - safer.


Explain why you think this is safer?

Over current and fault current protection accurately matching the
needs of the connected appliances and the circuit.

You what?


Overcurrent protection for each and every appliance selected at a
level appropriate for the appliance and not the circuit that feeds it.
One ogf the great benefits of fused plugs.


if the fuse is the correct rating, which few are.


All the fuses in my house are correctly sized for the appliance. Are
things different in yours?

Furthermore the fuse will be installed by the manufacturer, and is
highly unlikely to ever be replaced. Therefore your assertion that "few
are" the correct rating is obviously grossly inaccurate.

Fault protection can be provided independently of appliance protection
(and with discrimination), and can be designed so as to be appropriate
for the circuit.

Better discrimination on appliance overcurrent.

Nonsense.


If your appliance develops a fault and draws excessive current, it
will blow its plug fuse. Hence perfect discrimination. With a 16A
radial and no plug fuse you are relying on the circuit protection to
operate; even on a 500W appliance.


On radials many appliances have their own fuses, not relying on home
owners to select the correct rating.


Appliances frequently have their own fusing anyway - in addition to that
provided in the plug. The fuse in the plug providing primary protection
to the appliance flex. Another reason for the kludgy engineering that
requires appliance flexes in euro land to be sized to take full circuit
current rather than appliance current.


--
Cheers,

John.

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