Date: Fri, 16 May 2014 18:18:39 -0600
Reply-To: Gnarlodious <gnarlodious@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Gnarlodious <gnarlodious@GMAIL.COM>
Subject: Re: Off topic Friday question on switches...
In-Reply-To: <5376998d.0da8e00a.6423.5cdf@mx.google.com>
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So its called "split phase", that would make more sense for a home
workshop. If the motor has a low-torque startup delay in the broken switch
then he needs a special switch or risk motor damage and causing voltage
dropouts in the neighborhood
If the motor has a shaded-pole type delay built into the motor, he can use
a regular two phase switch. Or rather, a dual contact switch for 2-wire.
I would just say that using the plug as an on-off switch is a bad idea as
you can get arcing burns on your plug and socket and end up replacing them
later. Until then, burned contacts can generate heat and be a fire hazard.
I actually had this problem in my Vanagon with my old Iota battery
charger. When I plugged in the van capacitors (inductive load) inside the
charger would pull so much power the brass contacts would spark. After a
while I figured out plugs and sockets were burning up and sizzling causing
a hazard. And the problem was contagious, when you plug in a good extension
to one that has been burned it starts to burn the good wire, so after a
while all your wires are trashed at the ends. So a few months ago I
installed a new modern charger that doesn't spark when plugged in, problem
solved.
So a plug is not meant to be a switch for inductive loads, due to the high
inrush current.
-- Gnarlie
On Fri, May 16, 2014 at 5:04 PM, David Beierl <dbeierl@attglobal.net> wrote:
> At 06:43 PM 5/16/2014, Gnarlodious wrote:
>
>> Modern homes have 2-phase service to run resistive loads like clothes
>> dryers or water heaters, which use a special huge socket. The service box
>> is 2-phase but wired for single-phase loads. Except for the dryer and
>> oven,
>> which tap across 2 phases. You won't find any large inductive loads in
>> residential homes
>>
>
> Ok, we're talking about the same thing but disagreeing about what to call
> it. I really don't see how it's legitimate to call the output of a single
> transformer winding "two-phase" if you're not using the center tap, as you
> are not when you hook up 220V loads in US domestic service. Suppose that
> instead of grounding the neutral wire you grounded one of the hot wires.
> Now it would stay at earth potential and you'd have a 110V hot from the
> center tap and a 220V hot from the other end of the winding -- both exactly
> in phase. But leaving aside the practicalities of safety making this
> arrangement undesirable, you haven't actually changed anything.
>
> I think "split-phase" is a useful way to describe how we wire houses in
> the US, and "two phase" is not; especially when there are actual two-phase
> systems still in use in this country.
>
> Yours,
> David
>
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