On 17 Feb 2008 00:35:01 GMT, "DoN. Nichols"
wrote:

On 2008-02-16, Jerry wrote:



At one time I thought the static converter was a partially useful method
of running 3 phase machines at home, on single phase. But, the more I
learn about them, the more I recognize that they are an excellant device for
most home users for running 3 phase machines.

I agree, Jerry; static converters get an undeserved bad rap. I have
three machines (mill, lathe, surface grinder) that benefit from VFDs,
but my vertical band saw, belt sander, and one bench grinder run
happily on a static converter. (And, yes, turning one of those
machines on will help start a motor that the converter would otherwise
not start.)

I do have a large rotary converter, and can easily switch between the
static and rotary, but rarely find it necessary to run the (noisy)
rotary.


That depends. If you need to "plug reverse" a motor -- say do
it to a lathe spindle motor when you are threading up to a shoulder to
avoid a crash -- a static converter is useless.


And yet it works. I ran a Bridgeport for many years on a static
converter and regularly plug reversed when power tapping. A friend who
has a commercial shop without access to 3-phase runs 4 BPs on static
converters, and has for as long as I can remember. Plug reversing
isn't a problem for him, either.

Here's what Phase-A-Matic has to say:
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Next, you must determine whether to use a Regular or Heavy Duty
Converter. Keep in mind you can always use a
Heavy Duty Converter in place of a Regular Duty model. However, there
are some applications for which you
should always recommend Heavy Duty Converters. They a

1. Frequent starting or instant reversing (more than once a minute).
2. Unattended equipment, such as air compressors.
3. Long, heavy starting cycles, such as lathes without a clutch,
flywheel driven equipment, etc.
4. If jogging is required.
5. If there is a chance of the motor being stalled during use
(woodworking equipment, etc.)

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--
Ned Simmons