Circuit protection (was: RE: Latest addition : PDP 11/70)

From: Lance Costanzo <lance_at_costanzo.net>
Date: Thu Aug 2 08:54:02 2001

At 01:19 PM 8/1/01 -0700, you wrote:
>> From what I understand, every conductor must be capable of carrying a
>> current greater than the breaker that protects it. Otherwise, the cord
>would
>> be the first thing thing to fail in a overcurrent situation. This would
>> present a very significant fire danger.
>
>In the context of building wiring, yes. Not in the context of appliance
>wiring. 22GA zip cord, such as found on US lamps, isn't capable of
>sustaining 20A_at_115V without heating -- and you can certainly plug a
You have to look at it from the viewpoint of the load.
For a receptacle, its wiring back to the box must be capable of
handling the maximum load that can be plugged into it.
For a lamp, or anything else plugged into a receptacle,
the wiring must be capable of handling the device load.
In the case of a lamp, 100W, 150W tops.
You could get the right/wrong adapters and plug a table saw into
the lamp socket, which would probably fry the zip cord if the saw
could draw enough juice to start in the first place.
Received on Thu Aug 02 2001 - 08:54:02 BST