"robobass" wrote in message
...
I have a Sheppach table saw which constantly blows the fuse on startup. On
the motor it says 14.5 amps at 230 volts, which I interpret to be about 4
1/2 horsepower. I share my power with a bathroom fixtures supplier, and they
have the keys to the fuse box. Daytimes it's no problem. They are friendly
enough about switching my power back on. But, if they aren't there and the
power goes off, then I'm stuck for the day. People have suggested UPS's, but
I don't see any fit for my application. Any way to simply limit the current
spike for this motor on startup?

while not "simple", here's one method

http://www.baldor.com/pdf/manuals/834-602.pdf

On Mon, 3 Feb 2014 02:19:01 -0800 (PST), robobass
wrote:



A LOT of Euro and Asian gear goes 200-208. US tends to be 208-220, and

only the newer stuff runs 230-240.

Most Euro power is 230v with 16 amp breakers.

He certainly needs at minimum a 20 amp breaker no matter what.



TWO. One for the heaters, one for the saw.

Two would be nice, three better. One for heating, a second for the saw, and a third for everything else.

WHAT? You're running an entire flat and shop on a single breaker?


I've discovered that 3 phase is actually common in Germany, but it's different. Since each leg is 230v to neutral, then I presume that between legs it is around 460v. So, normally you don't have any two legs coming anywhere near each other. In a private house you might be able to access 3 ph. but not in a building, unless you want to pay for some expensive electrical work.

In my case, I'm running power from a secondary box in the courtyard behind the main building. That's almost certainly only 1 ph. I can add a couple circuits from there, but I wonder if the box itself can handle the draw. The idea of a cutout relay on the heaters now looks worth exploring.

Well, 100A circuit breaker boxes with 20 spaces, including 5 breakers,
go for $52 here in the USA. Double it for Germany, I guess. 200A
30-space boxes with 5 breakers go for $99.97 at HomeDepot. If you run
the wiring and install the box, then let the electrician verify it's
up to code and connect it, it'll save you $500 or so.


As things stand, it's only the combination of the saw and heaters which is creating problems. With the heaters running, I can still run the lathe, lights, and small machines without trouble, so at the moment there's no need to load up a trebuchet with stacks of Euro notes to attack this inconvenience!

Inconveniences like that can end up causing fires, so it's good that
you're going to do something to prevent it. The current sensing relay
is probably your cheapest, safest, best bet.

--
I have the consolation of having added nothing to my private fortune during
my public service, and of retiring with hands clean as they are empty.
-- Thomas Jefferson, letter to Count Diodati, 1807

Too bad -none- of the current CONgresscritters are willing to do that. -LJ

On 2/3/2014 6:21 AM, Rick wrote:
while not "simple", here's one method

http://www.baldor.com/pdf/manuals/834-602.pdf

It is simple from a user's standpoint: 2 wires in, 2 wires out. Easy
peasy. As to cost ...
Bob

"Bob Engelhardt" wrote in message
...
On 2/3/2014 6:21 AM, Rick wrote:
while not "simple", here's one method

http://www.baldor.com/pdf/manuals/834-602.pdf

It is simple from a user's standpoint: 2 wires in, 2 wires out. Easy
peasy. As to cost ...
Bob


The schematic is there for the adventurous....

Well, 100A circuit breaker boxes with 20 spaces, including 5 breakers,

go for $52 here in the USA. ...


Well, it's not the cost of the box and breakers. It's how much juice is coming to it which is at issue. If I can get away with running an extra line or two from the courtyard box, I'm in good shape. If I need to run more wire from the main building, then I'm looking at bonfires of money.

On Mon, 3 Feb 2014 09:54:38 -0800 (PST),
wrote:



Well, 100A circuit breaker boxes with 20 spaces, including 5 breakers,

go for $52 here in the USA. ...


Well, it's not the cost of the box and breakers. It's how much juice is coming to it which is at issue. If I can get away with running an extra line or two from the courtyard box, I'm in good shape. If I need to run more wire from the main building, then I'm looking at bonfires of money.

Hopefully, you have the capacity at the courtyard. G'luck.

--
The most powerful factors in the world are clear
ideas in the minds of energetic men of good will.
-- J. Arthur Thomson

robobass wrote:

Two would be nice, three better. One for heating, a second for the saw, and a third for everything else.

I've discovered that 3 phase is actually common in Germany, but it's different. Since each leg is 230v to neutral, then I presume that between legs it is around 460v.


Closer to 400 volts between phases.

On Wed, 05 Feb 2014 17:01:53 -0500, "Michael A. Terrell"
wrote:


robobass wrote:

Two would be nice, three better. One for heating, a second for the saw, and a third for everything else.

I've discovered that 3 phase is actually common in Germany, but it's different. Since each leg is 230v to neutral, then I presume that between legs it is around 460v.


Closer to 400 volts between phases.

Yup - just under - 398.7 +/-

wrote:

On Wed, 05 Feb 2014 17:01:53 -0500, "Michael A. Terrell"
wrote:


robobass wrote:

Two would be nice, three better. One for heating, a second for the saw, and a third for everything else.

I've discovered that 3 phase is actually common in Germany, but it's different. Since each leg is 230v to neutral, then I presume that between legs it is around 460v.


Closer to 400 volts between phases.

Yup - just under - 398.7 +/-


I know. I rounded it before posting. Anyway, what's 1.3V (.326%)
among friends? ;-)

Closer to 400 volts between phases.

That makes sense. I've never learned the maths on this, but sort of understand.

Many stoves and instantaneous water heaters here run on 1 ph. 400v. So it would appear that as long as you have 3 ph. going into the building, then it's easy enough to run two wires to the local box and get your 400v. As I said, most older buildings don't have this option, so either there's only one phase running into the building, or the construction electricians didn't foresee the usefulness (or they did, but saw $$$ in the future by not doing it then!). In 1965 there were no blow dryers or microwave ovens, and in our flat there's not even central hot water to the kitchen! There was a stupid useless little 5 liter pressureless boiler under the sink when we moved in.. I fixed that by running copper pipe from the bathroom, but I'm not sure that was even legal... Well, Germans lived pretty low to the ground in those days compared to the suburban house I grew up in in Ohio, but at least our houses and buildings don't burn down easily!

My shop troubles aside, I live in a 1965 five story apartment building where juice is also tight. I've got 4 16a/230v breakers to run my 1000 sq.ft. flat. When I gut renovated the kitchen (where the power comes into the unit), I had to be somewhat creative about how to partition things so that no breaker was overloaded. The box and meter are across the common hallway, so running additional wires/circuits is cost prohibitive. We don't typically have metal conduit in this kind of housing. The wiring is just tacked up to the base layer, and plastered over. It's pretty primitive, but we mostly get away with it. Since it's 230v, no wire has to carry the amps that North American wires do.