On Fri, 28 Dec 2007 14:54:13 -0800 (PST), willray
wrote:

On Dec 28, 2:20?am, wrote:
On Fri, 28 Dec 2007 13:27:12 -0800 (PST), willray
snip
Any thoughts on preventing the
phase-converter electronics from _trying_ to start, unless the
idler is spun up? Not like it's a huge problem if it just blows the
breaker on start up if some idiot (most likely me) hits the start
button
without spinning the idler up with the pony motor, but the purist in
me thinks that using that as a safety is inelegant.

Can't use a potential relay to cut over, since it won't reliably
generate
much until L1 and L2 are provided.

If you use a single phase pony motor to spin up the idler to
near full speed, the centrifugal switch drop out on the pony
motor will signal when it's safe to power up the idler.

Jerry Fosters' comments are also valid. If you go this
route it pays use a good sized, switched in, idler start
capacitor. This is a double win - it both increases the starting
torque and reduces the peak starting current. The increased
starting torque reduces the time duration of the surge and this
makes it less likely to trip the breaker.

Jim