Again, I think we need clarification about what country this is in. In
the US, white should NEVER be hot. In some situations, it is done, but
at the very least it should be marked as such with tape. The standard
is definitely white=3Dneutral, black=3Dhot, green=3Dground. There are
several more allowed hot colors.

See: http://www.allaboutcircuits.com/vol_5/chpt_2/2.html

The above link indicates that in the UK, black is sometimes used as
neutral, which I can see could be easily confused with the US
black=3Dhot.

Sean


On Wed, Dec 9, 2009 at 5:17 PM, Philip Pemberton <piclist@philpem.me.uk> wr=
ote:
> PICdude wrote:
>> I recently picked up a used reflow oven (APS GF-12) and it does not
>> have a plug -- just 3 bare wires (12ga white, green and black). =A0The
>> prev owner said it was hardwired and thinks it was 3-phase, but IIRC
>> 3-phase requires 4 wires... or not???
>
> I doubt it's three-phase.
>
> I'd probably go with single-phase AC. Green being the ground, white
> being phase, and black being neutral. You should be able to (at least)
> figure out which one is ground by doing a continuity check between the
> case (assuming it's metal) and the ground wire.
>
>> I have 2 options for outlets here at the office...
>> (1) a Nema L6-30 ( http://www.ezdiyelectricity.com/?p=3D238 )
>> (2) Another similar outlet, but the prongs are in a smaller circle.
>> It says "Hubbell twist-lock 20A 250V plug".
> =A0> - Are both of these outlets single phase?
>
> Looks like two-phase to me (is that even possible?). 250V between the
> two phases, plus one ground.
>
>> - Is this oven a single-phase oven? (APS only made these as 220V
>> single-phase or 220V 3-phase).
>
> Looks like it to me.
>
>> - Is there a standard for the colors on the plug wires?
>
> Pass. I'd put money on green being the ground wire, though.
>
>> - Is there any way to check the oven =A0for the correct phase
>> requirements (resistance tests, etc) before I damage the oven?
>
> See above -- if there's metalwork (or the case is metal) then you should
> be able to do a continuity check between the metalwork and the wires to
> figure out which one is ground.
>
>> =A0and APS won't speak to
>> me unless I give them $2000 first.
>
> Ah, the good old "support contract"...
>
> --
> Phil.
> piclist@philpem.me.uk
> http://www.philpem.me.uk/
> --
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