[sudo-discuss] Electrical stages proposed

Tue Aug 19 12:58:01 PDT 2014

Hol,
We must keep in mind that placing multiple 240V plugs on the same line is
ill advised because there is the potential for more than one plug being
utilized (with unknown Amperage requirement) at the same time thus tripping
the breaker. Its best to have dedicated breakers for these heavy loads. The
maximum number of outlets per 20A breaker is 10, so any combination of 3d
priting area, museum, Eastern wall etc is possible provided we are 10 or
less.

Although maximizing the outlets per breaker to leave room for the 240V
service is possible, that option is motivated by a limited view of our long
term needs. Yes, there would be room in the Balcony box for all our
immediate needs, however, what about our exhaust requirement when welding
(that's two more 240 circuits- one for the welder and one for the exhaust
motor). Those leads would have to come from somewhere other than the
Balcony box. I therefore propose that all 240 service be from the Above
Stage panel. That said, I don't see the benefit of running the 240 in phase
1 of this installation.

Conduit size. We certainly will have left overs of hardware, if we are
working with 3 different sized condi then we'll have 3x the leftovers. 1/2"
is about $2/10ft - 3/4 is about double that @ $4/10ft and 1" is about
$8/10ft. Conduit benders are expensive ranging from 25-50 per bender but
they can be rented from the tool lending lib or purchased from a flea mkt.
I'll keep the idea of using all 3/4" in mind.

Let's make a home depot run soon (this wkend at the latest).

-Whit

On Tue, Aug 19, 2014 at 11:35 AM, <hol at gaskill.com> wrote:

>  hey whit,
>
> I think we may as well run the 230 along with 115 over to the shop area
> and leave only the overhead work until later.  If we are going to use the
> same conduit to run all conductors, we may as well pull the 230 along with
> the 115.  to touch on the limited real estate inside the breaker box, i
> agree about having a dedicated breaker for the server farm.  with the other
> 3 slots available, you indicated that 2 would be taken up for the 230V
> since we're energizing 2 hot conductors.  with the remaining slot, would it
> be possible to power the 3d printing area, the 'museum,' and still put some
> 115V outlets on the back wall?  thanks for taking the time to do all this
> analysis of the code for us.
>
> using all 3/4" conduit (instead of 1/2" and 1" as originally shown in the
> spreadsheet) and purchasing one bender would make it easier in terms of
> getting clips etc in bulk that could be used throughout the building if we
> have leftovers.
>
> do y'all know when the fire inspection is scheduled?  the more work we can
> get in under the first round the better, if for no other reason than not
> feeling like we immediately need to do more electrical work after the fire
> inspection.  i will have alot more time to help out during the next few
> weeks, and would be glad to drive on a home depot run if we're ready to
> pick up supplies this weekend.
>
> on amperage requirements, the welder that's there now uses 7 amps at 115
> iirc, and for example a lincoln weldpak180HD uses 20 amps at 230.  from
> what i understand there is not 3-phase power coming into the building at
> all, so the best course of action would be to install 2 single phase 230
> plugs - one for a welder or plasma cutter or other heavy machine, and one
> dedicated to the robot, with the intent to use a rotary phase converter to
> provide 3-phase power.
>
> cheers,
>
> hol
>
>
>
>
>
>
>
>
>
>
> On 2014-08-19 10:50, Whitney Lawrence wrote:
>
>  Upon further consideration and based on input from our community I
> recommend we move forward in Stages.
>
> First Stage: Service the server area (dedicated 20A breaker), 3d print
> area and Museum with another 20A breaker. Thus satisfying the Fire
> inspection needs.
>
> Stage 2, phase 1: Install plugs along Eastern wall (3rd 20A breaker)
>
> Stage 2, phase 2: Install 240V service to Robot on Eastern wall. Other
> 240v needs?
>
> Stage 2, phase 3: Install overhead power (either using the 4th available
> position of the Balcony breaker or tying into the 3d printer/museum j-box)
>
> I need to know about the Robot power requirements. I looked through the
> manuals posted by Jake and have not found the amperage rating for the
> control box+robot. Im working under the assumption that she requires a 30A
> dedicated 240V supply and Jake will preform 3phase magicianary.
>
> The reason I ask is because I need to size the breaker accordingly, and we
> have limited real estate within the Balcony panel (located in the music
> room). Currently (no pun intended) there are 4 breaker positions available
> in the Balcony panel. I think that all 240V supply, be it 30A(robot?) or
> 50A(welder?) any exhaust fans, dust collection service or whatever will
> have to be supplied from, not the Balcony panel, but the sub that feeds the
> Balcony called "Above Stage" panel.
>
> I recommend having dedicated breakers for the 240V supplies. Unless we
> know exactly what will be powered, there is no way of passing the <50%
> amperage usage per plug requirement of the NEC. This is simply the best
> practice. Furthermore, this should not be an issue if we are using the
> "Above Stage" panel because according to notes on the panel, most breakers
> within are not being utilized- so there is plenty of space.
>
> I'll continue to draft the drawings based on what I have written here.
> Hopefully the package will be complete and ready for review by this Friday.
>
>
> https://docs.google.com/spreadsheets/d/1Fgw5himtlmemiXReP-fG6rP-I2RoXsSP_MAZxcNUUm0/edit#gid=1250155659
>
> Thanks,
> Whit
>
>
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