Re: 240V feeder and HV cabinet ground question, Miss-communicated

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Gerry  Reynolds" <gerryreynolds@xxxxxxxxxxxxx>

Hi Jim,

Since you will be standing at the cabinet during operation, the cabinet 
needs to be grounded to mains safety ground.  Since your pig is in the 
cabinet, its case should be grounded to the cabinet.  If you have any 
120Vac loads in your sub panel, you will need to return the AC current into 
neutral.  Otherwise, you wont need to connect to neutral.   Neutral should 
be grounded to earth ground at the breaker box only using a connection to a 
water pipe or to a rod in the ground.   The load end of neutral should not 
be grounded a second time else galvanic corrosion could 
result.  Personally, I would add a ground cable from the cabinet to the RF 
ground rod that the secondary coil is connected to (and only during 
operation) to provide a return path directly back to the secondary just in 
case there is a strike to the TC primary.  This would be used in 
conjunction with the safety gap on the pigs HV bushings (or near the 
bushings if a filter is between the safety gap and the bushings) that would 
shunt the current from a strike to the TC primary into the pigs case and 
cabinet ground.

Gerry R.

> Original poster: "Jim Mora" <jmora@xxxxxxxxxxx>
>
> Sorry for the obvious confusion here:-)There is NO swimming pool.
> Esthetically, my wife found the green pool cabinet acceptable.
>
> [#1] The question is whether the pig case, neutral strap removed ,neutral
> unused, and the "pool" cabinet be Grounded to the Mains ground, an Isolated
> ground rod, or the RF ground (nearby). The direct burial cable to the pig
> has (2) #8awg and a ground from my dedicated sub-panel, which has a 25 foot
> 4 run of #4awg (Neutral, Hots, and Utility Ground) to the Service Entrance
> (mains) on a 60amp breaker.
>
> The neutral is NOT bonded in the sub-panel per audio grounds loops, planes,
> and stuff I still don't understand, although it is grounded to a water pipe
> nearby which still connects it to neutral indirectly which may be worse.
>
> [#2] Should I just bond the neutral screw in the sub-panel?
>
>
>
>
> -----Original Message-----
> From: Tesla list [mailto:tesla@xxxxxxxxxx]
> Sent: Friday, June 03, 2005 12:44 PM
> To: tesla@xxxxxxxxxx
> Subject: Re: 240V feeder and HV cabinet ground question
>
> 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
> <snip>