"John Rumm" wrote in message
...
BigWallop wrote:

If you think you're only going to run up to 6 kW running ampage, then you'll need
to
treble that amount to take the start up ampage of the motors on the machines all
running together. This will also allow for any strain on the working motors under
their normal use.

Not any expert on 3 ph setups, but I was under the impression that you
designed cable sizes for the working load and not the startup current
since it is only a short duration transient?

Cheers,

John.


Generally you would only allow for the motor start up surge but these motors will be
under strained load conditions while they work and not just start up and run at a
constant rate. Three phase gives you a motor that can keep torque even though it is
slowing under tension loading. As an example, a lift motor can reach the same load
rating while lifting a heavy bin as it does when it first starts dry. So you don't
just rate loading on three phase commercial tooling machinery as you would with a
static motor on say a ventilation system or the like.


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