Not exactly true. GOOD boxes like Square D alternate, there are
some older units that have the left side of the box on one phase,
the right on the other. I found some #12 neutrals in a house I
bought that served two breakers next to each other in one of
those. Let's see, 2x20 amps = 40 amps to blow the breakers on a
12 ga wire. not good.

Replaced and upgraded the box promptly.

Bob Robinson wrote:

benwoodward.com wrote:

You have a house.
You have no 220v outlets easily accessible.
Yes you do.
Even if you don't.
Thank heavens for oscilloscopes.
All the 120v breakers on the left side of you breaker box are 180
degrees(or Pi radians for the less mathematically inclined) out of
phase with all the 120v breakers on the right side.
Find a room or outlet where the lights go out when you flip off a left
side breaker and plug a 25 ft grounded extension cord into it.
Find a room where the lights go out when you flip off a right side
breaker and plug a 25 foot grounded extension cord into it.
Get a voltmeter and measure hot(little slot) to hot and you will get
240v.
Totally usable up to the value of the smaller of the two breakers.
You can wire nut a third cord with a 240v receptacle into the first
two hot to hot and you will have a female 240v outlet wherever you may
go, provided there are two rooms, one on each 120v side of the breaker
box, within 50ft of each other.
I discovered this accidentally with my oscope a month ago.
So I say screw the dynasty, get the HTP invertig 200.
I'd rather spend 5 extra minutes hunting for an outlet and triple my
welding capability versus trying to get 120v to act like anything more
than a wonderful tool for hampster experiments at NIMH.


The phases alternate vertically in your breaker box, they are not split
left and right!!! Look at a 220 breaker, it is made to span two
adjacent slots on one side of the box, not two slots on opposite
sides... Not only that, there is no guarantee that any room will have
outlets of both phases present.