Re: 240V feeder and HV cabinet ground question

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Yurtle Turtle <yurtle_t@xxxxxxxxx>

I forget what your project is, but if you are planning
on running near a pool, there is something you may not
be aware of. NEC requires all metal in and around a
pool to be bonded. This means that if you are running
a coil and someone touches anything metal, such as
supports for a diving board, ladder, slide,
pump/motor, etc, they "may" get a shock, depending on
how you wired and grounded your device. Bonding
connects all metal parts together, but generally
doesn't include a ground rod. Instead, a fairly large
conductor goes back to the house panelboard (breaker
box). That way, your pool pump/motor, lights, etc. are
all connected to the same house ground. My concern is
if you have someone in contact with the house ground,
by sitting on a diving board, depending on how your
control panel is wired up, there could be a hazard.

Adam

--- Tesla list <tesla@xxxxxxxxxx> wrote:

> Original poster: "Jim Mora" <jmora@xxxxxxxxxxx>
>
> Hello all,
>
> I am planning to put my 14400/5KVA along with my HV
> DC components in a
> gutted Swimming Pool cabinet. The cabinet will be
> bolted to a preexisting
> concrete slab. It is about 50 feet from my dedicated
> 60 amp Pump safety
> switch. Witch is well grounded to the mains (#4)20
> feet away and a copper
> water pipe. That is probably a neutral no-no but it
> is close. This is where
> my control rack will be rolled.
>
> The ongoing saga of ground questions:
>
> 1. The HV cabinet is at nearest 8 feet from one of
> three RF ground rods
> (maybe not connect this one to the coil?).
>
> 2. I have 70 feet of AWG# 8 direct burial w/ground,
> 18" ground cover, a
> minimum 16 feet parallel to the TC planed location.
>
> 3.IMPORTANT: shall the HV cabinet thoroughly
> grounded with the mains along
> with the case lug of the Pig (no neutral
> connection). HV out will be floated
> on both sides via 50KVDC cable 10 to 12 feet long.
>
> Note: current limiting will be entirely attempted by
> break rate and a large
> variac for voltage ramp up. And yes I have a breaker
> box adjoining the
> safety switch with 30, 40, and 50 amp main breakers
> at hand. The control
> cabinet has a large contactor in it and will be
> energized by a remote fiber
> momentary dead man switch.
>
> Any help on question #3 will be greatly appreciated
> as I view it as a safety
> issue.
>
> Thanks
> Jim Mora
> Ojai Ca.
>
>
>



		
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