On 9/18/2019 8:10 PM, Unquestionably Confused wrote:
On 9/18/2019 9:02 PM, Clare Snyder wrote:
On Wed, 18 Sep 2019 17:40:16 -0700 (PDT), DerbyDad03
wrote:

On Wednesday, September 18, 2019 at 11:20:53 AM UTC-4, Bob La Londe
wrote:
On 9/18/2019 7:35 AM, Bob La Londe wrote: On 9/18/2019 7:14 AM,
Jack wrote:
Â* On 9/17/2019 11:49 AM, Bob La Londe wrote:
Â*


[SNIP]

I have turned down some pretty impressive equipment that would have
been
free except for the cost to transport it because if I ran it I'd
have to
turn off everything else in the shop.Â* LOL.

I do have some battery backup emergency LED flood lighting in the shop.
So far they have only kicked on during my routine tests, and when we
have had a general power failure.


Do you at least have the lights on their own breaker? It really sucks
when
a tool plunges the whole shop into darkness if it trips the breaker.
Â* WShen it kicks the main breaker having the lights on their own
doesn't help unless they are running on a battery - - - -

I'm not really concerend about tripping an individual breaker. The only
thing I have that might do that is the big Miller Mig Welder and I only
use it when nothing else critical is running due to fear of
electrical/RF noise causing a CNC machine to crash. I have forgotten
and used it anyway a couple times. Nothing bad happened.


That would be true if there weren't any circuits in the panel, just the
100 amp breaker.Â* If the power tool was on, say, a 60amp circuit
breaker, wouldn't the lights remain on assuming a separate 20amp circuit?


Nothing in my shop should trip its individual breaker even under peak
load except the welder listed above. I have it on a 50 amp breaker, and
the books says it should be on a 65. However, if I had say 3 2HP mills,
the 5HP mill, the 1HP mill, all hit peak load in an inside corner cut at
just the exact moment the air conditioner or the air compressor (3.7HP)
motor started up I'd be worried. Particularly if I was also taking a
heavy cut on the 3HP lathe at the same time. You might add that all up
in your head and say, "Hey that's under 70 amps," (On 230V) but that is
not accounting for the draw of all the servo and stepper motors. The
servos on one machine are setup to pull as much as 35 amps at 90VDC
each. They typically pull less than 5 amps, but in that theoretical
peak load in a poorly planned inside corner cut they could draw a lot
more. Then you have to remember that there are atleast 3 such motors on
all five CNC mills. Not all of which are that heavy, but it all adds
up. Ever one of those machines is on its own dedicated breaker sized
appropriately for the machine.

The reality is not all of those machines are running all the time even
though the goal is to have them all running when I am in the shop.
Also, the odds of everything in the shop pulling peak load or overload
at once is pretty slim. Probably infintesimal. Of course the main
breaker would not trip the instant it hit 100amps either. Like most
breakers it takes atleast a few seconds of overload or extreme overload
to trip. I could very likely run one or two more 5HP machines or 4-6
more 2HP machines if I had breakers to put them on. My 100 amp sub
panel has 2 60 amp subpanels of its own. I only have two spare breakers
in the whole building. Both are 120V. Yes I am using compact breakers.