DerbyDad03 wrote:

wrote:
On Thu, 31 Oct 2013 08:36:12 -0700 (PDT), Pavel314
wrote:

Our greenhouse heater wore out after a number of years so we bought a
replacement. It's essentially the same heater except that the new one is
a different color and the plug is a different configuration. The old one
has one round pin and two flat blades, with the blades at an angle to
each other and above the round pin. The new one also has one round pin
and two flat blades but the blades are lined up with each other, so I
have to replace the receptacle with one that matches the new plug. Not a
major project, just a minor annoyance and expense.

I've seen other 220 volt plug configurations; some have an L-shaped
blade instead of the round pin, others have four blades in a circular
pattern which lock when turned, etc. Is there any practical reason for
all these variations?

Paul


Maybe this will shed some light on it

http://upload.wikimedia.org/wikipedi...d_pins.svg.png

I could use a little more light to be shed...

Why do they use the text "Welder or Plasma Cutter" above the L6-20 and
L6-30 plugs?

Are there no other devices that use a locking 20A or 30A plug?

Tons. They just noted the common uses for some of the configurations.

To the OP, you can't just change the receptacle style randomly, you have
to ensure that the circuit is the correct voltage and Ampacity to match
the receptacle and also the device you intend to connect. Those
different styles exist to prevent people from plugging a 120V device
into a 240V circuit, or a 50A device into a 20A circuit or similar.