You can split a 400 amp run but each pair of conductors should be sized to handle 400 amp fault current. The conductor needs to match the fuse or breaker that feeds it.
Your sub panel is 200 amps so after that it only needs to be sized for 200 amps.

Rich & DJ <rdj@...> wrote:
I have a question if I am legal by code rules. I bought this place 4 years ago and here is how it was wired. , I have my own 400 amp transformer on a utility pole in the yard, at the bottom of the pole there is a 3 phase 400amp disconnect with only two lines in use and fused. There is no 400A 240V disconnect standard so a 3 phase box was used, From there I have one run to the work shed and a 200 amp breaker box and another run to the home and a 200 amp breaker box. I have wondered about the splitting of the 400A run.
The shed has my work shop and my radio room. In the shed I have a welder, air compressor, saws and future amp set up. I don’t want to rewire more than I have to, to be safe. Right the 240v for the welder and air compressor is a 3 wire setup. All original wiring in the shed was done in conduit.
The radio room has the breaker box in it so it will not be hard to rewire for an amp. I built a universal (variable voltage) power supply for the amp and it has a 3 wire cord from a range now.
This place is out in the sticks with the hicks and the ticks so wiring was not inspected after it was first run.

Rich, kd0zz:

Outside Feeder Tap of Unlimited Length Rule [240.21(B)(5)
Outside feeder tap conductors can be of unlimited length without
overcurrent protection at the point they receive their supply, but
they must be installed in accordance with the following requirements:
Figure 3
(1) The tap conductors shall be suitably protected from physical
damage.
(2) The tap conductors shall terminate at a single circuit breaker or
a single set of fuses that limit the load to the ampacity of the
conductors. This single overcurrent device shall be permitted to
supply any number of additional overcurrent devices on its load side.
(3) The overcurrent device for the tap conductors is an integral part
of a disconnecting means or shall be located immediately adjacent
thereto.
(4) The disconnect is located at a readily accessible location either
outside the building or structure, or nearest the point of entry of
the service conductors.
--
Eddie, WB4MLE

My new GE stove the fourth wire goes to case ground N goes inside. No 120 volt outlet. A stove always used the neutral to pass current in low heat settings.

R L Measures wrote:

开云体育

Jim,

Do you think there is any difference in the voltage capacity of fixed or
variable vacuums caps by Jennings specified for the same DC voltage?

73
Peter


________________________________

From: ham_amplifiers@... [mailto:ham_amplifiers@...]
On Behalf Of pentalab

RICH SEZ... A 15kV - tested Tune-C would do the job - provided that
the DC blocker cap was ahead of the Tune-C. With a 7000V anode
supply, and a g-g triode, the AC anode potential would be c. +/-
6700V-peak. Since the RF rating of a vacuumis 60% of it's DC
rating, or 9000V in this case, a 15kV cap would do the job. -
note - The "Plywood Box" amplifier used a 15kV tested Tune-C and a
9000V NL anode supply. The Tune C did not arc.

### Rich, when are u gonna read the posts more carefully ???????
We are talking about using a FIXED vac cap.... AS A PLATE
BLOCKER !!!!!!!!!!

--- In ham_amplifiers@..., R L Measures <r@...> wrote:

### This applies to any HV supply/linear amp as well. The
neutral if used.... is fed to it's own separate buss
bar/termination in the HV supply/amp...... and the neutral is
NEVER bonded to the chassis. If u did... u would have any and
all devices operating on 120 vac...having their return current
flowing back to sub panel via GRND. And since the sub panel has
isolated grnd/neutral buss's..... this 120 vac current would
continue back to MAIN panel ..VIA the grnd wire tying the sub and
main panel together.

### IE: The grnd wire[s] only are designed to carry FAULT
current.... and NEVER normal operating current.

### When Rich or anybody else advocates bonding the Neutral to
the chassis in any HV amp/RF deck/anything else... BEWARE... you
are violating the electrical code in all 50 states, and all of
Canada.

RICH SEZ....Beware of what? -- certainly not electric shock.

### I give up !

### Why don't u take some of that 4 wire home depot 8 awg...
and parallel em into 2 pairs.... eq ga is then 5ga. Then u
will have all 4 wires carrying current... and can run ur 8171.

Jim

I have a question if I am legal by code rules. I bought this place 4
years ago and here is how it was wired. , I have my own 400 amp
transformer on a utility pole in the yard, at the bottom of the pole
there is a 3 phase 400amp disconnect with only two lines in use and
fused. There is no 400A 240V disconnect standard so a 3 phase box was
used, From there I have one run to the work shed and a 200 amp breaker
box and another run to the home and a 200 amp breaker box. I have
wondered about the splitting of the 400A run.
The shed has my work shop and my radio room. In the shed I have a
welder, air compressor, saws and future amp set up. I don't want to
rewire more than I have to, to be safe. Right the 240v for the welder
and air compressor is a 3 wire setup. All original wiring in the shed
was done in conduit.
The radio room has the breaker box in it so it will not be hard to
rewire for an amp. I built a universal (variable voltage) power supply
for the amp and it has a 3 wire cord from a range now.
This place is out in the sticks with the hicks and the ticks so wiring
was not inspected after it was first run.

Rich, kd0zz:

--- In ham_amplifiers@..., R L Measures <r@...> wrote:

On Nov 18, 2006, at 1:42 AM, pentalab wrote:

### Jenning's told me, IF you are going to use.. say
a FIXED vac cap... as a PLATE BLOCK CAP [don't laff... LOADS of
11m QRO amps use fixed ceramic/glass vac caps as plate
blockers... mounted vertical... connected with a special clamp,

to

the center anode typ .82" solid pin] that the vac cap has to be
DE-RATED by 60% for V. IE: For an amp with say 7 kv no load
HV supply.... use a min of a 20 kv test rated vac cap.

RICH SEZ... A 15kV - tested Tune-C would do the job - provided that
the DC blocker cap was ahead of the Tune-C. With a 7000V anode
supply, and a g-g triode, the AC anode potential would be c. +/–
6700V-peak. Since the RF rating of a vacuumis 60% of it's DC
rating, or 9000V in this case, a 15kV cap would do the job. -
note - The "Plywood Box" amplifier used a 15kV tested Tune-C and a
9000V NL anode supply. The Tune C did not arc.

### Rich, when are u gonna read the posts more carefully ???????
We are talking about using a FIXED vac cap.... AS A PLATE
BLOCKER !!!!!!!!!!

Jim

On Nov 18, 2006, at 6:47 AM, pentalab wrote:

--- In ham_amplifiers@..., R L Measures <r@...> wrote:

The issue is not what the latest NEC requirements happen to be,
it's questions like: Does it make electrical sense that to

be "safe" we need 4 wires for a 240v circuit, where 2 of the 4
wires carry zero- current? Recently when I was at Home Depot, I saw
a reel of 4- conductor #8 Cu. At first it struck me as odd, but
then it dawned on me that this was the NEC's latest rule for
wiring electric ovens and dryers.

### Rich... u still don't "get it".

Correctomundo, Jim

On any stove made in the
last 45 yrs... they all have a 120 vac outlet..sometimes two.

My GE has no outlets, but it does have a 40w, 120v lamp.

Most still have a row of glass fuses inside the top cover. A
stove would have to have a neutral just to run the 120 v stuff.
The built in light runs on 120 v. I'm not quite sure.... but
think the small burners on top run on 120 v.. may be wrong.

Semi-correct. 120v on low heat. 240v on high heat.

I
think they ran 2 x burners from one hot leg.... and the other 2
burners from the other hot leg.

Not on my GE.

## To recap.... 3 of the wires carry current. The 4th is to
save ur skin.

In someone's theory, yes, in reality, if no 4th wire were used, with a dead short from one L to N at the stove, there would be c. 50V on the enclosure for <2-seconds.

later... Jim VE7RF

R L Measures, AG6K, 805.386.3734
r@..., rlm@..., www.somis.org

dialco makes a nice plug in neon lamp. Theis standard socket takes leds from 5 to 28 VDC (with built in resistor for each voltage)?or a neon. Very nice stuff. We use them on front panels of our test equipment.

craxd wrote:

Gents

My buddy was recycling his old sand filled fuses... by soldering
a single strand of 26 ga wire across the 5" long fuse. Fine
so far.

Amp was running fine the other night... the next day... BOTH HV
fuses were blown open..... and amp was off from the previous
night !

A real mystery. He then decided to solder TWO 26 ga wires
across each of the old HV fuses. Next step was adding a small
resistor to one hot leg of 250 cfm fan.. to slow it down a bit.
[cools the glitch..... which diss 450 w with a dead cxr... 100 w
on ssb]

At that point all hell breaks loose. The paralleled 100 ohm 225
watt wire wound glitch R's looked like u hit both of em with a
propane torch for 30 mins each.... charcoal !! We know a HV
to chassis fault occured... may have been a faulty RFC bypass cap.

The point here is.... by oversizing the HV fuse.... the load is
then transfered to the 100 A breaker in the 240 v main 200 A
panel.... which of course didn't blow open...... instead the
glitch R's fried themselves... !

You need well over 100 A to open a 100 A panel breaker.

Over sizing a HV fuse is bad enough.... and you guys want to
operate with NO hv fuse at all ?? nuts.

BTW... that Dahl A-540 hypersil C core 253 lb plate xfmr I
have... has a .01 ohm primary.... and a 6.06 ohm sec [5200 v
tap] You got any idea how much current you can suck from one of
these things ..... LOADS... as my buddy with the same 253 lb xfmr
just found out. 253 lb xfmr with a core good for 20 KVA
CCS with a 100 A slo breaker... vs lowly glitch R [wound with
nichrome wire no less] .... no contest.... glitch loses every
time........ unless a correct sized HV fuse is used !

later... Jim VE7RF

I uploaded a small pic of a neon panel lamp assembly to the photos
section to see if anyone knows who manufactures these? They are the
same press in neon lamp lens that Heathkit, B&K, and several others
used for indicator lamps on their equipment. They press in a 5/16"
round hole, and a Tinnerman nut is pressed over the lens from the
rear to hold it. The outer lens you see is about 3/8" OD, and tapers
outward about 1/4" long. The total length is about 7/8" to 1". The NE-
2 type neon lamp is then slid in the rear opening of the lens and
it's leads soldered to the circuit. They are made of a translucent
plastic either clear, red, amber, or green if I recall. I'd like to
buy several hundred of these lens if I can find the manufacturer.

Mouser has a similar smaller version, but they're not translucent,
and are really made to use an LED with. I have some of these too, but
don't like them. I'm needing the larger ones like Heathkit used in
Amber, red, or clear color. These wre used as the power indicator
lamp on a Heathkit IM-5228 and IM-18 bracket mount VTVM.

pic;




Thanks,

Will

On Nov 18, 2006, at 1:42 AM, pentalab wrote:

--- In ham_amplifiers@..., "craxd" <craxd@...> wrote:

For checking vacuum caps, you really need HV DC to test them with
since that's really what they'll be blocking. I'm not familiar

with

that brand Hipot, but that sounds like the control is for

capacitive

reactance compensation. I'm not sure that will be that accurate
testing those with an AC current. You might look for a manual on

the

net you can download and see how to use that with the control in
mention.

Best,

Will

### Will... re-read his post. He used a JENNINGS brand HI-POT
tester... not brand .."X" I remember reading in the old
Jennings engineering application section... that it was strongly
suggested to only use AC hi-pot test devices. Apparently... when
HV DC is applied to any vac cap... the cap will grow whisker's
from the soft OFC copper stator/rotor plates. plus bellows on
variable caps. Jenning's told me, IF you are going to use.. say
a FIXED vac cap... as a plate block cap [don't laff... LOADS of
11m QRO amps use fixed ceramic/glass vac caps as plate
blockers... mounted vertical... connected with a special clamp, to
the center anode typ .82" solid pin] that the vac cap has to be
DE-RATED by 60% for V. IE: For an amp with say 7 kv no load
HV supply.... use a min of a 20 kv test rated vac cap.

A 15kV - tested Tune-C would do the job - provided that the DC
blocker cap was ahead of the Tune-C. With a 7000V anode supply, and
a g-g triode, the AC anode potential would be c. +/– 6700V-peak.
Since the RF rating of a vacuumis 60% of it's DC rating, or 9000V in
this case, a 15kV cap would do the job. - note - The "Plywood Box"
amplifier used a 15kV tested Tune-C and a 9000V NL anode supply. The
Tune C did not arc.

### One would think for a brief Hi-Pot test.. that DC HV hi-pot
tester would be ok... it's not.

Page 6, Jennings Vacuum and Gas Capacitors catalog:
"DC: Vacuum capacitors should not be operated in DC applications
above the peak RF working voltage."

I'll try and dig out my
Jenning's notes to find out why.
I think the DC HV types can be
used...

Vacuum capacitors don't come in DC and in AC types.

but certain conditions were applicable in their usage. ...

R L Measures, AG6K, 805.386.3734
r@..., rlm@..., www.somis.org

--- In ham_amplifiers@..., R L Measures <r@...> wrote:

The issue is not what the latest NEC requirements happen to be,
it's questions like: Does it make electrical sense that to

be "safe" we need 4 wires for a 240v circuit, where 2 of the 4
wires carry zero- current? Recently when I was at Home Depot, I saw
a reel of 4- conductor #8 Cu. At first it struck me as odd, but
then it dawned on me that this was the NEC's latest rule for
wiring electric ovens and dryers.

### Rich... u still don't "get it". On any stove made in the
last 45 yrs... they all have a 120 vac outlet..sometimes two.
Most still have a row of glass fuses inside the top cover. A
stove would have to have a neutral just to run the 120 v stuff.
The built in light runs on 120 v. I'm not quite sure.... but
think the small burners on top run on 120 v.. may be wrong. I
think they ran 2 x burners from one hot leg.... and the other 2
burners from the other hot leg.

## To recap.... 3 of the wires carry current. The 4th is to
save ur skin.

later... Jim VE7RF

Jim,

I'm familiar about the whisker problem, but by what I've read from
several places, that happens over time and not instantly. By that,
Jennings would be saying that these whiskers grow instantly since a
Hipot test doesn't take but a minute. I don't know if Comet or any
other vacuum cap manufacturers give a Hipot warning beside Jennings.

I'm not familiar with the Jennings Hipot, I did see that. However, I
own an Associated Research DC Hipot, and in their manuals they give
the testing of fixed vacuum caps using a DC Hipot. Variable ones
wouldn't see any DC of course being used as Tune and Load C if a DC
blocking cap is placed before the tank circuit. I'll look through the
A.R. manual again, but I never seen a warning about it.

Does Jennings make the cup plates with the same soft copper as the
bellows? One would think they would use a harder copper for the
plates and bond the soft copper bellows to them.

Best,

Will

--- In ham_amplifiers@..., "pentalab" <jim.thomson@...>
wrote:

--- In ham_amplifiers@..., "craxd" <craxd@> wrote:

For checking vacuum caps, you really need HV DC to test them with
since that's really what they'll be blocking. I'm not familiar

with

that brand Hipot, but that sounds like the control is for

capacitive

reactance compensation. I'm not sure that will be that accurate
testing those with an AC current. You might look for a manual on

the

net you can download and see how to use that with the control in
mention.

Best,

Will

### Will... re-read his post. He used a JENNINGS brand HI-POT
tester... not brand .."X" I remember reading in the old
Jennings engineering application section... that it was

strongly

suggested to only use AC hi-pot test devices. Apparently... when
HV DC is applied to any vac cap... the cap will grow whisker's
from the soft OFC copper stator/rotor plates. plus bellows on
variable caps. Jenning's told me, IF you are going to use..

say

a FIXED vac cap... as a plate block cap [don't laff... LOADS of
11m QRO amps use fixed ceramic/glass vac caps as plate
blockers... mounted vertical... connected with a special clamp, to
the center anode typ .82" solid pin] that the vac cap has to be
DE-RATED by 60% for V. IE: For an amp with say 7 kv no load
HV supply.... use a min of a 20 kv test rated vac cap.

### One would think for a brief Hi-Pot test.. that DC HV hi-

pot

tester would be ok... it's not. I'll try and dig out my
Jenning's notes to find out why. I think the DC HV types can

be

used... but certain conditions were applicable in their usage.

### The best thing GUILLERMO can do... is to e-mail Jenning's
directly for a manual... or if not available... at least ask them
what the XC compensation is for. Perhaps a google search using
the model number may bear results.

## I believe it was to compensate for the XC of the vac cap
itself, under test. I believe.. for different values of fixed
capacitance.... the XC compensation had to be correctly dialed
in...1st. And on vac VARIABLES... when hi pot testing at min

+

max C... the XC compensation also had to be tweaked for a

specific

C value. The C of the cap had to be measured 1st on any variable
cap.

### As far as I know... Jenning's still makes their hi pot
tester.... which was designed specifically for their vac
products..... including vac relays. It was very expensive... if I
recall. As I recall... it could also be used on HEC ceramic
doorknob caps... and also Centralab [now ITT/Jennings]

### I'm sure Jenning's would be able to help him out asap... then
we can find out what the XC compensation is for. IMO... he's
got the ultimate hi-pot tester. The AC test freq was always
60 /50 hz. The Xc at that low a freq would be sky high... on a
low C cap... and a little lower on a high C cap.

Later... Jim VE7RF

--- In ham_amplifiers@..., GGLL <nagato@> wrote:

Past days I was able to try a Jennings HiPot tester with

On Nov 17, 2006, at 4:09 PM, pentalab wrote:

--- In ham_amplifiers@..., "Phil Clements" <philc@...>
wrote:

I looked. In our breaker box, all the ground wires and all the
Neutral wire connecct in one bus bar. How would it be different

if

there were two bus bars that are connected by a bus-wire?

No electrical difference here; but if the breaker box is to be

used as

a sub-panel, you need seperate bus bars for the neutrals and

grounds

with a removable shorting strap between the two. Only in the main
service entrance panel do the neutrals and grounds all strap

together.

I guess a few bucks are saved by leaving out the strap and

insulation

for the two bus bars if one has no intention of ever changing a

main

panel over to a sub-panel.

### This is correct. Only SUB-panel's are wired for separate
grnd/neutral buss's.... via the shorting strap. I installed a 100
A sub panel... and such is the case. The reason is... they want
any fault current to flow through the GRND buss bar... back to
main panel.... and NOT the neutral.

I'm talking about a hot to chassis short only... inside the HV
supply/amp/ anything else. This requires by the electrical
code... to have a separate GRND wire from sub panel to HV
supply/amp CHASSIS. Of course their is also a grnd wire tying
the main and sub panel together.

### any short from hot to neutral... in the HV
supply/amp/anything else including sub panel itself... and fault
current will flow back through the neutral.... back to main panel.

### This applies to any HV supply/linear amp as well. The
neutral if used.... is fed to it's own separate buss
bar/termination in the HV supply/amp...... and the neutral is
NEVER bonded to the chassis. If u did... u would have any and
all devices operating on 120 vac...having their return current
flowing back to sub panel via GRND. And since the sub panel has
isolated grnd/neutral buss's..... this 120 vac current would
continue back to MAIN panel ..VIA the grnd wire tying the sub and
main panel together.

### IE: The grnd wire[s] only are designed to carry FAULT
current.... and NEVER normal operating current.

### When Rich or anybody else advocates bonding the Neutral to
the chassis in any HV amp/RF deck/anything else... BEWARE... you
are violating the electrical code in all 50 states, and all of
Canada.

Beware of what? -- certainly not electric shock.

### The shorting strap used in main panel is heavy ga copper
bar... and never wire. .... used to bond neutral buss and grnd
buss's together.

In my breaker box, the neutral wires and the ground wires go into the same bus strip. When there's a fault, the breaker trips.

...

R L Measures, AG6K, 805.386.3734
r@..., rlm@..., www.somis.org

The issue is not what the latest NEC requirements happen to be, it's questions like: Does it make electrical sense that to be "safe" we need 4 wires for a 240v circuit, where 2 of the 4 wires carry zero- current? Recently when I was at Home Depot, I saw a reel of 4- conductor #8 Cu. At first it struck me as odd, but then it dawned on me that this was the NEC's latest rule for wiring electric ovens and dryers.

cheers, Jason.

On Nov 17, 2006, at 9:24 PM, Jason Buchanan wrote:

I think by all of us comparing notes and adding to each other's

knowledge

base and laying it out here maybe only 13 Hams/CBers will blow

their asses

off wiring amplifiers in their mobile homes this year.

I'm so glad we could be of assistance to the general population

like this.

Somebody should give us a medal or something.

See link below for more details regarding new 2007 NEC wiring amendments:



--
73 Jason N1SU...

R L Measures, AG6K, 805.386.3734
r@..., rlm@..., www.somis.org

Has anyone mentioned the possibility of hum that could be present with no
neutral?

-John, N9RF