Ecnerwal wrote:
In ,
wrote:

I Googled but didn't find anything that would
work quickly.

Who makes an inexpensive tester that I can plug
into 208 V 3 phase L14-30 outlets to determine
phase rotation?

I'm aware of this circuit but I want something
I can buy at the Borg and leave at a worksite:
http://www.opamp-electronics.com/tut...on_2_10_03.htm

--Winston

I don't know that they have ever been all that cheap - the volume market
isn't really there to bring the price down. 3-phase implies industrial
implies prices tend to be rather stiff. I used to put them in as part of
our vacuum pump controls (wired in, not a plug in unit), but they were
special-ordered and several hundred bucks when several hundred bucks
went a bit further than these days.

I see one for $23 that you'd have to wire the plug to (phase indicator,
google shopping, not hard to find) - can't be left plugged in (1 hour
limit at 200V, 4 minutes at 480 - I guess they use cheap resistors to
make a cheap meter)

Step up to ~$80 and you can get a perhaps somewhat better built extech
480400 meter (you'll still need to wire in your plug.) It does not
mention any time limit for being connected, so you might not have to buy
a replacement meter after one gets left and fries...

Yup. I saw the 10 W resistors in some designs, so
the temptation to 'cheap out' would be great.

Thanks!

--Winston