Re: electrical deaths

On 2024-11-28 04:24, Don Y wrote:

On 11/27/2024 6:33 PM, Carlos E.R. wrote:

But a tea kettle or a bread toaster or the microwave plug into 120, drawing quite some amps.

 Many electric tea kettles have the element IN the kettle.  So, there is
an EASY "mate/unmate" connection between the kettle and its base (a set
of concentric rings).  A small one (~1 liter) typically has a 1500W rating.
 A "2 slice" toaster (you can find them in 4 slice models as well) is
typically 1000W.
 Microwave ovens are 600-1000W.
 Toaster ovens are 1200 to 1800W.
 (Belgian) Waffle iron, pizzelle iron, et ilk are in the 700-1800W range.
 [Keep in mind that US homes tend to have a pair of 20A (2400W) "small
appliance" circuits to address countertop loads in the kitchen.]
 Most other "pluggable" small appliances are in the 200-600W range
(hand/stand mixers, blenders, etc.)  All kitchen pluggable appliances
tend to be sold with short power cords (18-24 inches).  As such, are
plugged and unplugged typically with each use.
 [This leads to wear and tear on the plug and receptacle, both of
which lead to increased losses IN that connection, over time.]
 Hair dryers are nominally 1000W.
 All of these are often cheap, "tinny" products -- not built very robust
(save for "better quality" microwaves and toaster ovens) -- because they
CAN be built "cheaply" (cost&quality) and consumers tend not to want to
spend much on them.

I forgot about room heaters. Here most of them are 2KW each, maybe switchable to 1KW.

 

If those connections get a bit rusty, they also get hot. And they need thick wires; thick copper is not that easy to wrap around connectors.

 A 20A branch circuit (e.g., countertop services) is fed by 12AWG conductors
(hot, neutral and earth).  Additionally, use of receptacles RATED for 20A
loads tends to lead to improves quality of that receptacle.
 OTOH, many are wired (by homeowners!) with "back stab" connections where
the ends of the individual conductors are stripped of insulation and then
then "poked" into holes in the back of the fixture where a spring-loaded
mechanism grips them.  This is typically not as robust as "completely"
(270 degree) wrapping a conductor around a screw that causes both sides
of the wrapped conductor to be in contact with the screw/terminal.
 Additionally, many folks "daisy chain" the inbound "feed" THROUGH the
fixture to the outbound (i.e., two separate connections for each conductor
on the fixture).  As the fixture (receptacle) is "exercised" by the
insertion and removal of plugs, small motions cause the stiff wires to
loosen.  If this happens at an upstream fixture, then that connection
may be passing most of the current drawn on that branch circuit
(instead of JUST the current used in that fixture).
 [A better wiring technique is to connect inbound and outbound conductors
under a wire nut (sized for the number and size of conductors) along with
a "pigtail" to feed the fixture.  In this way, the downstream loads
are firmly connected to the "feed" and only the current flowing through
the fixture (via the pigtail) is susceptible to loosening AT the fixture.
But, this is more labor intensive.]
 

Yep.
--
Cheers, Carlos.