[SML] L21-30 power supply

[Richard Niederberg]

Dear Frank,
We do not want an overloaded neutral or weird harmonics to be present
ANYWHERE in the system. Two out of three legs maxed out can cause problems
elsewhere in the installation, especially if the Delta-to-Wye transformer
was being fed by a service with a 'wild' leg.
/s/ Richard
_________

On Sat, Feb 28, 2015 at 11:22 AM, e-mail frank.wood95 <
frank.wood95 at ntlworld.com> wrote:

> Richard.
>
> Why do you think this? Dimmer packs are essentially single phase
> devices, the total load being spread across three phases for reasons
> of load balancing. If your breakers work on strict trades union
> principles (One out: all out) tripping one breaker will lose you the
> whole works, and tou've lost the whole show. With two phases left, you
> can usuallyy cobble up enough lights to keep going.
>
> I've had to dothis once when the isolator developed a mechanical fault.
>
> Three-phase machinery is a different question. Motors get awfully
> confused if they lose one phase, so it is right for them.
>
> On 28 February 2015 at 15:11, Richard Niederberg via Stagecraft
> <stagecraft at theatrical.net> wrote:
> > Dear Tim,
> > For Dimmer Packs, you should plug straight in to the breaker panel, so
> all
> > the 'hots' trip together, if the breakers are mechanically interlocked,
> > which they should be for maximum safety.
> > /s/ Richard
> >
> > On Sat, Feb 28, 2015 at 7:00 AM, Tim Nielsen via Stagecraft
> > <stagecraft at theatrical.net> wrote:
> >>
> >> Hey list,
> >>
> >> I have a L21-30 power supply mounted to the side of a breaker panel in
> my
> >> shop for a chain motor.  I've never used it, but lately on shows I've
> found
> >> myself in need for more power available on stage.
> >>
> >> I know Lex makes their "Bento Box"
> >> (
> http://www.lexproducts.com/products/entertainment/powerhouse-portable-distribution-boxes/20-30-amp-portable-distribution-boxes/30-amp-bento-box-with-tail-input-to-nema-receptacles
> )
> >>
> >> This looks like exactly the product I need, unless I'm overlooking
> >> something.  Does anyone know about any other products I could use?  I've
> >> seen a few adapter cables, but they all seem to output at 208v, which
> isn't
> >> useful to me.
> >>
> >> My plan would be to use it for power for bands on stage, occasional
> extra
> >> dimmer packs, running a couple of circular saws on stage, etc., not
> constant
> >> use.
> >>
> >> Thanks!
> >>
> >> -Tim
> >>
> >> --
> >> Timothy Nielsen
> >> Episcopal High School
> >> Technical Director
> >> Office:  (703) 933-4172
> >> Email:  TDN at episcopalhighschool.org
> >>
> >> ____________________________________________________________
> >> For list information see <http://stagecraft.theprices.net/>
> >> Stagecraft mailing list
> >> Stagecraft at theatrical.net
> >> http://theatrical.net/mailman/listinfo/stagecraft_theatrical.net
> >
> >
> >
> >
> > --
> > /s/ Richard
> > _________
> >
> > ____________________________________________________________
> > For list information see <http://stagecraft.theprices.net/>
> > Stagecraft mailing list
> > Stagecraft at theatrical.net
> > http://theatrical.net/mailman/listinfo/stagecraft_theatrical.net
>
>
>
> --
> Frank Wood
>



-- 
/s/ Richard
_________
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