开云体育

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

--- 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

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


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

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

vacuum

capacitors (all 250 pF, 30 KV; some were Jennings, China made, with

ceramic

bodies, others of another USA brand which I do not recall and the

more

"traditional" glass envelope). This tester feeds an AC voltage upto

60 KV

peak; it has a control called "XC compensation". There was no

manual so all

was a try and guess. The effect I observed was to modify uAmmeter

reading.

Which is the main purpose of that control?.

Best regards
Guillermo - LU8EYW.

Jason,

I hate to even write this as some joker working with the NEC might
take it to heart and have it done, LOL! Anyhow, I have seen times
when I did wish a cable did have two bare grounds in it, and it was
permissable to use. The reason being is that when you bring the cable
into an outlet box, junction box, etc, the bare ground has to be
connected to the box and the outlet or switch. The ground wire from
the cable then needs two 6 inch pieces of bare wire attached to its
end using a pigtail splice with a wire nut. That's three wires
twisted together under the nut. Then one 6" wire goes to the green
screw on the outlet or switch, and the other 6" wire is applied to
the box with a ground clip, or under a ground screw head. All this
then gets stuffed inside the box. By having the extra ground, that
splice then dissapears and there's more room in the box. One ground
wire to the outlet, and one to the box. When your wiring junction
boxes from a wall switch for a lamp, then you have two cables coming
in, with all the grounds needing to be spliced together (four bare
under a wire nut). This can be kind of hard to stuff all that in a
box.

The more wire in a box, the fire hazard increases. After a certain
number of wires in a box, the box has to be re-sized larger to pass
code. I can't remember though if they count the spliced on wires as
being counted each, or they count them all as one. If as one, it
would make more room I would think, but the extra ground wire might
make it go over the box limit, I'm not sure. It would get one out of
that splice with a large wire nut which takes up a good bit of room.
The problem then arises making the cable stiffer and harder to pull!

Anyhow, that was just a thought I've had when installing switches,
etc and curssing over trying to stuff all that in a small box (10
pounds of shit in a 5 pound bag).

In the photo, I wonder why the one bare ground is stranded? I guess
that's the extra-extra ground that would cover a spec for either
stranded or solid... Hi Hi!!

Best,

Will



--- In ham_amplifiers@..., "Jason Buchanan" <jsb@...>
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

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

I enjoyed reading all through this one to see what all the little comments
were.

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.

:-) BOB DD

Past days I was able to try a Jennings HiPot tester with some vacuum capacitors (all 250 pF, 30 KV; some were Jennings, China made, with ceramic bodies, others of another USA brand which I do not recall and the more "traditional" glass envelope). This tester feeds an AC voltage upto 60 KV peak; it has a control called "XC compensation". There was no manual so all was a try and guess. The effect I observed was to modify uAmmeter reading.
Which is the main purpose of that control?.

Best regards
Guillermo - LU8EYW.

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

--- In ham_amplifiers@..., "Robert B. Bonner"
<rbonner@> wrote:

Jim,

I know several years ago a friend sent me some copies of the

posts

on AMPS

when I wasn't a member. There were comments rather heated

regarding POWER

SERVICES and AC wiring to amps.

### yes.. that was cheap entertainment... happens every 4 yrs
on 'AMPS'.

I will end that quickly here as I won't tolerate incorrect info

to

pass me

by. You are a smart guy, very knowledgeable and have some good

experiences

but let's define power services / wiring correctly to avoid any

errors.

You and I are saying the same things but differently. Separated

by a common

language.

### agreed.

I worked three years as an electrician... Knew my business.

### I'm not.. but gotta work with em, and power engineers once
in a while... sometimes major projects.

Standard 220V residential circuits are two wire, the third wire

is

a GROUND

(Green) not a neutral.

### partially agreed . In Canada... ALL 220 v appliances

EXCEPT

a hot water tank, are 4 wire.

Most dryers are 2 wires plus ground here.

### Our dryers are all 4 wire. The motor is always 120 v..
separately internally fused from one of the hot legs. Dunno why..
seems silly a 220 v motor isn't used.



You wire your Ameritron its two

wires plus a ground.

### agreed... ditto with RL drake amps. No neutral needed. They
do it that way for one reason.... to sell em in EU/VK/ZL, etc...
where all they have is 220 V, 2 x hots + grnd. NO neutral in
the normal sense. In the UK... one side of the 220 V IS
grnded.... so look at that as one hot 220 v leg.. and one grnded
neutral leg.

If you have a 4 wire 220 circuit including Power Cord and a 4

conductor

plug... Two blacks a white and a green. You have 220 plus

neutral. This

will give you 220V via two 120 circuits and a ground. This is a

direct

extension of your panel service.

## agreed.

Most residential 220V items don't use 4 wire.

## see above.

Not to be confused with 3 Phase which is all different colors /

uses.

### agreed. With 3 phase.. u gotta worry about cw or ccw
rotation as well.... esp with interfacing with gen sets. 208 V
is popular... simply cuz any phase to neutral is 120 v. We

also

use 480 V 3 phase... but NO neutral.

In residential services in the states we tie the NEUTRALS and the

GROUND

Buss together in the main panels, however that NEVER by

definition

makes

them "the same thing". Neutral is Neutral and Ground is always

Ground.

### agreed.... but only main panels.... not sub panels. [strap
removed between gnd and neutral buss on all sub panels.]

Try switching them in a ground fault circuit and the breaker will

blow.

The green wire should NEVER conduct current. SO if you are

utilizing a 120

volt transformer somewhere in your homebrew for a control circuit

or

filament you should also be utilizing either a 220-120V step down
transformer in your construction OR a 4 wire 220 circuit to meet

code...

### yes... all of my 120 v blowers, fil xfmrs, etc... utilize the
4 wire cicuit. Each of the 120 v devices is individually

fused.

That meets code.

This is why large commercial HF power generators like the Henrys

(even the

8K) have 220-120 step down transformers inside them.

Others use 220V filament transformers not 120 to meet the

electrical code...

Why don't they use all 220 transformers? New regs requiring both

legs to

blow when one goes. They put gangbared main breakers on the

gear,

but

utilize 120 volt fuses for all the other small circuits to save

money. The

220-120 step down is cheaper to fuse than dual breakers on all

circuits.

Now will it work your way? That is 120V circuits wired to one

side of the

line? YES... Does it meet code? No...

### sure it does. You even said so a few paragraphs above...
as long as a 4 wire circuit is used... and individually sub
fused for the 120 v stuff.

### Any 220 v stuff HAS to use a tie bar between poles of
breaker. Having to open BOTH sides of a 220 v circuit just
killed any notion of using separate fuses per leg.... or
breakers without the ganged tie-bar. Dunno about my concept of
using BOTH a ganged 2 x pole breaker AND high speed fuses...

one

fuse per hot leg... downstream of ganged 2 x pole breaker. IF
just ONE fuse popped open.. the other fuse would remain intact...
and the slower 2 x pole ganged breaker would remain intact....
the result being.. only one leg is opened off. Meanwhile, ur

Dahl

plate xfmr loses power on primary..... until Joe ham... thinking
the power is OFF... gets in there...inside... grnds out one leg

of

xfmr.... and ends up with 120 V fed to the 240 v primary...
resulting in 1/2 normal plate V, etc. With one hot leg

still

intact [say it was 30-100A]... joe ham could still manage to
either electrocute himself... or melt stuff.

That being the case... and not being able to install fast fuses

per

leg..... to protect a HV supply.... the only real option is a

HV

fuse + glitch R. The best I can see for a 240 v primary... is
using "controlled magnetic hydraulic" breakers... with the 2 x
poles ganged together. Most of em come in different trip curve
ratings... so u want the FASTEST one possible.

I still can't find a half decent 100-A FAST magnetic

breaker....

in any catalog.... haven't looked at all of em though.

FYI The base Alpha 77 wasn't UL approved. It had a hot ground

wire. There

was a higher cost version that had a step down transformer in it

if you

REQUIRED a two wire circuit. That's mentioned right in their

manual.

### amazing. IF one is going to the trbl of installing a new
240 V line to schack.... you may as well do it right the 1st
time... and install a 4 wire curcuit.

You are correct on all the other points. The separate CB's

wouldn't fly

today without a tied together gangbar to kill both sides of the

AC

line.

A Grandfathered in system does not make it a good system. :-(

That's what I was referring to as CHEATING The System. Breaking

the

Electrical Code.

Since we are basically saying the same thing differently... We

have no

argument.

## agreed. I should obtain a copy of the latest code... since
mine is dated... I knew of SOME of the updates ... but not all....
like the new code sez all new homes must have arc detectors for
all bedrooms etc.

### In a lot of cases... if one is doing major updates on an
older home... they will want EXISTING... other stuff brought up
to new code standards.

### I dunno if AL conductor's are even allowed in homes
anymore. One home I had in the 80's had 12 ga AL wire...instead
of the usual 14 ga CU. I'm sure it was eventually banned. I
can see why. My son's bedroom duplex outlet ended up like

charcoal

one day. The AL conductor's... doesn't matter how tight u crank
the screws.... always ends up going slack.. then u get a
resistance joint, etc. Pwr co's use exclusively AL conductor's
in the field... cuz of weight... and cost.

They done away with aluminum romex cable, too many trailer and house
fires over it. The trailer (mobile home) industry used it the most.
Heavy aluminum cable has to be installed with an anti-corrosive on
the bare aluminum after it's stripped. The stuff we used came in a
plastic squirt bottle like ketchup is in at a restaurant. It was a
black greasy like stuff. You applied it to the bare aluminum wire
before it's placed in the terminal hole and the set screw tightened
down on it. It'll not pass an inspection if that's not applied to
aluminum wire anymore. They still use the large aluminum cable for
electric furnaces - heat pumps in homes.

later.... Jim VE7RF

BOB DD

Best,


Will

When I worked as an industrial electrician for several years after I
moved up here, we had them several places within the plant. However,
they were all on circuits that had several motors running. The push-
in jig at ACF Industries has about 16 hydraulic units on it, each
with about a 5 HP, 3 phase motor. That was where one large cap was
mounted overhead. I used to have to check it once a month on P.M. as
it had PCB's in the oil. We had to check it for leaks. There was a
few others, one in the power house where some M-G units were that
made the DC for some overhead cranes. That's about the only ones I've
been around besides some that were in plants where I was working in
engineering, and didn't have to fool with them anymore. I've never
seen any used with a transformers secondary. The reactance created by
motors can drop the power factor down a good bit. They were only
recommended to be used at a PF of under 0.80. Then, you spec them by
kVAr instead of capacitance. You find the recatance of the circuit in
question to calculate them, but they are sized and bought really by
specing a kVAr rating. What the kVAr rating is compared to
capacitance, I don't know. One might look into a catalog for them to
see. Then you also have to worry about harmonics too. They make these
up as PF corrector-harmonic filters also. They attach to each of the
three line legs of the 3 phase circuit. Some use a power monitor to
kick in and out the bank of caps when needed.

I think it would end up costing more, and placing more of a load on a
transformer by connection a cap across the secondary. It would be
similar to connecting a resistance of some amount in parallel with
the winding acting like a leak raising the current.

Best,

Will



--- In ham_amplifiers@..., "Robert B.
Bonner" <rbonner@...> wrote:

Guys,

My first job out of my undergrad program was with a building

automation

(energy) company. We installed PFC caps on buildings all over the

place.

At that time I wasn't the engineer doing this, but I was around it

enough.

There's formulas for balancing the act.. How much capacitance to

add etc

depending on the current PF and how many HP of motor load...

PFC is used because Electric motors exhibit a HELACIOUS Inductive

load on

the mains while converting to work.

In an inductive circuit the voltage leads the current by 90

degrees. This

inductive load tosses the power company out of SYNC. They are busy

trying

to match things up at the power plant.

They generate 3 phases of power. The load on the generators'

phases needs

to be balanced. A way off power factor screws the system. If

everybody

allowed the PF to get away from them you'd have a real mess... The

idea is

to make the current flow run in sync with the AC sign wave.

Commercial power is sold with a base rate for so many KWH, the

demand (how

fast you use it) and a premium penalty for power factor varying

from 100%.

I worked with an injection molding plastics factory. The big

injection

machines had very large motors and that place's PF was way the heck

out

there.

Instead of correcting the building.. We installed smaller

correction banks

on each machine (about 40 of them at that time) as you can have

too many

caps installed and shift the PF the other way.

We generally don't measure PF in residential as there isn't a huge

supply of

big motors throwing things off. Some areas with demand limiting of

energy

conservation do-do demand metering and control. None I've seen

here do PF

measuring at the residential level.

For the Super Big guns that are running 100 AMP primarys with three

phase

power supplies doing PFC will just make the power to the primary

smoother

and your power company happier. I don't think it is worth the

expense for

correction caps. Either way I would install them on the amplifier

not the

building.

BOB DD

-----Original Message-----
From: ham_amplifiers@...

[mailto:ham_amplifiers@...]

On Behalf Of craxd
Sent: Friday, November 17, 2006 6:22 PM
To: ham_amplifiers@...
Subject: [ham_amplifiers] Power factor correction for transformers

I looked through about every book I have on transformers and power
supplies, and never found anything about using a cap for power

factor

correction. There's plenty about using a cap with an AC motor, but
nothing about transformers. The Standard Handbook For Electrical
Engineers only show adding them to motor circuits or circuits

feeding

motor loads. Nothing under the transformer section.

The only power supplies to use a power factor correction cap was a
few switching power supplies. It was used after the rectifier and
before the choke though. It was never placed in the AC line. I did
see some series regulated supplies in transceivers that had a cap
across the secondary in a bridge rectifier supply, but it was for a
filter. Their values ran from 0.001 uF to 0.01 uF. Nothing of any
size.

The only way to cut back on magnetizing current is to use more iron
in the core lowering its flux density. The more iron for the same
amount of turns, the current drops. I researched magnetizing

current

in C-core Hipersil (or M-6) transformers some time back, and seen
they had a good bit more magnetizing current than most EI cores

using

M-19 steel. The reason being is they run Hipersil from 15 to 17
kilogauss. M-19 and M-22 are ran from 14 to 10 kilogauss. Over 15
kilogauss in Hipersil, the current really shoots up. The way to

cure

this is to have a transformer wound with the same number of turns,
but with a larger core area in either a C-core or an EI core. One
would have to tell the winder to use a lower flux density of say 12
to 10 kilogauss using a C-core with Hipersil or M-6 for a low
magnetizing current. M-19 for an EI core may be a better choice if
available as it will be a good bit cheaper. The core loss isn't

much

greater than M-6 either.

The links below go to several webpages and a couple of PDFs on the
subject.

switch_mode_power_supplies/

power_optimizing_singlestage_power/









Best,

Will





Yahoo! Groups Links

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

Correct, even though in reality, they tie together at the main panel.
The way it used to be, all the breaker boxes used for a service main
(main panel), like a 200 amp service in residential construction,
have a common bus bar for both the neutral and ground. This bus bar
is also bonded to the cabinet. These are the same as you will buy at
Lowes and Home Depot. When you want a sub panel, you ask for and buy
a sub panel as they're two different beasts. A sub panel could be
used as a main panel, but both bus bars (ground and neutral) have to
be tied together. Most sub panels though generally have a lower
current rating like 100 amps or less. I guess you could buy them
larger, but generally in residential construction, the sub panel is
smaller than the main panel. I don't know of any houses being built
today that use less than a 200 amp main. They used to have 100 amp
mains like this house had before I changed it out. I put in a heat
pump back in 1989 and had to upgrade to a 200 amp.

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.

Correct. What Rich is saying is that since the ground and neutral tie
together at the main, they still in reality are the same wire. The
difference is that the neutral carries operating current back to the
main, and back to the C.T. of the transformer. Since the neutral
carries current, it's insulated. The ground though, being bare, is
used for safety and shouldn't have but a momentary fault current flow
in it. If a break in the hots insulation was to occur inside the
cable jacket, it should possibly (HOPEFULLY) short to the bare ground
and the fault current kick the breaker. That's why armored BX cable
is better than Romex. Since the bare ground is bonded to the steel
outlet or pull boxes, a short from the hot to a box will cause a
fault current to travel through the ground wire, back to the main,
and trip the breaker. The bare ground should be connected to the
chassis of the amp so that if a short happens between the chassis and
the hot (shorted transformer), the fault current will flow through
the ground wire, back to the main, and trip a breaker. The NEC
figures that the neutral is a current carrier and so it's insulated,
and the ground is only a temporary fault current carrier.

New TV sets throw this out the door as they all have a hot chassis
any more. The fault current goes back through the neutral if the fuse
don't blow.

Here, the C.T on a lot of transformers at the pole go to a ground rod
at the pole. The home also has a ground rod going to the ground/
neutral bus bar. Water pipes are not a good ground since most tap on
to the main water line via pvc pipe anymore, via a high pressure
fitting. Same goes for a well which uses PVC pipe. If the copper
water lines attached directly to a cast iron water main, it would be
pretty good. Most water mains here are thick wall, large ID plastic
anymore. You also would have a meter to feed through where a bond
jumper would need to be put across it. The water itself is not that
good of a conductor for a ground.

### 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.

See above. It's so you don't have operating current on a bare ground
wire.



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.

Correct!

### 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.

### 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. [it might have to handle 100+ A] I have never
seen any panel yet, without isolated neutral and gnrd buss's.
That's cuz with isolated grnd/neutral buss's..... any panel can be
used as a main OR sub panel.

Here, you used to either buy a sub panel or a main panel. My Square D
main panel has a common bus bar where a series of holes are up either
side. There's two rows of set screws up the front over the holes. In
it, you can have a ground right under a neutral. I just seen a single
bus bar main panel by Square D at Lowes the other day while I was
looking around.

Your correct on a shorting jumper. It has to be able to handle the
maximum current the box is rated at. For a main, I prefer the single
bus bar.

The proper way of running a 115/230 Vac circuit is to use either 10-3
or 8-3 etc romex. There you have a black, red, white, and bare
ground. Black and Red are the two hots, White neutral, and bare is
ground.

A 230 Vac only circuit could be ran with say 10-2 or 8-2, but the
white would have to be re-colored by tape or heat shrink to pass an
inspection. In some areas, I'm not sure whether that would be
acceptable as local building codes can differ.

If using cordage like type SO cord, I always buy like 10-2 with black
and red instead of white. It costs a little more, but to me worth it.
Ground is always green in all.

Some cordage like is being used in computer power cables though have
blue and brown or black for the power if I recall, and green as
ground.

Grey 3-wire zip type cord can be used as it has no color except the
green ground in the middle. This is similar to dryer pig tails, etc.
I've used this cable to wire 60 amp fused disconnects for 225 amp
welders (buzz boxes).

The big heavy 230 vac cable for a heat pumps, etc main current is
similar to service entry cable in a grey rubber jacket. The two hots
are black with a bare ground. The wire is aluminum. I'm not for sure
the current capacity of the stuff I have here though.

Later... Jim VE7RF

(((73)))
Phil Clements, K5PC

Best,

Will

--- In ham_amplifiers@..., "Robert B. Bonner"
<rbonner@...> wrote:

Jim,

I know several years ago a friend sent me some copies of the posts

on AMPS

when I wasn't a member. There were comments rather heated

regarding POWER

SERVICES and AC wiring to amps.

### yes.. that was cheap entertainment... happens every 4 yrs
on 'AMPS'.

I will end that quickly here as I won't tolerate incorrect info to

pass me

by. You are a smart guy, very knowledgeable and have some good

experiences

but let's define power services / wiring correctly to avoid any

errors.

You and I are saying the same things but differently. Separated

by a common

language.

### agreed.

I worked three years as an electrician... Knew my business.

### I'm not.. but gotta work with em, and power engineers once
in a while... sometimes major projects.

Standard 220V residential circuits are two wire, the third wire is

a GROUND

(Green) not a neutral.

### partially agreed . In Canada... ALL 220 v appliances EXCEPT
a hot water tank, are 4 wire.

Most dryers are 2 wires plus ground here.

### Our dryers are all 4 wire. The motor is always 120 v..
separately internally fused from one of the hot legs. Dunno why..
seems silly a 220 v motor isn't used.



You wire your Ameritron its two

wires plus a ground.

### agreed... ditto with RL drake amps. No neutral needed. They
do it that way for one reason.... to sell em in EU/VK/ZL, etc...
where all they have is 220 V, 2 x hots + grnd. NO neutral in
the normal sense. In the UK... one side of the 220 V IS
grnded.... so look at that as one hot 220 v leg.. and one grnded
neutral leg.

If you have a 4 wire 220 circuit including Power Cord and a 4

conductor

plug... Two blacks a white and a green. You have 220 plus

neutral. This

will give you 220V via two 120 circuits and a ground. This is a

direct

extension of your panel service.

## agreed.

Most residential 220V items don't use 4 wire.

## see above.

Not to be confused with 3 Phase which is all different colors /

uses.

### agreed. With 3 phase.. u gotta worry about cw or ccw
rotation as well.... esp with interfacing with gen sets. 208 V
is popular... simply cuz any phase to neutral is 120 v. We also
use 480 V 3 phase... but NO neutral.

In residential services in the states we tie the NEUTRALS and the

GROUND

Buss together in the main panels, however that NEVER by definition

makes

them "the same thing". Neutral is Neutral and Ground is always

Ground.

### agreed.... but only main panels.... not sub panels. [strap
removed between gnd and neutral buss on all sub panels.]

Try switching them in a ground fault circuit and the breaker will

blow.

The green wire should NEVER conduct current. SO if you are

utilizing a 120

volt transformer somewhere in your homebrew for a control circuit

or

filament you should also be utilizing either a 220-120V step down
transformer in your construction OR a 4 wire 220 circuit to meet

code...

### yes... all of my 120 v blowers, fil xfmrs, etc... utilize the
4 wire cicuit. Each of the 120 v devices is individually fused.
That meets code.

This is why large commercial HF power generators like the Henrys

(even the

8K) have 220-120 step down transformers inside them.

Others use 220V filament transformers not 120 to meet the

electrical code...

Why don't they use all 220 transformers? New regs requiring both

legs to

blow when one goes. They put gangbared main breakers on the gear,

but

utilize 120 volt fuses for all the other small circuits to save

money. The

220-120 step down is cheaper to fuse than dual breakers on all

circuits.

Now will it work your way? That is 120V circuits wired to one

side of the

line? YES... Does it meet code? No...

### sure it does. You even said so a few paragraphs above...
as long as a 4 wire circuit is used... and individually sub
fused for the 120 v stuff.

### Any 220 v stuff HAS to use a tie bar between poles of
breaker. Having to open BOTH sides of a 220 v circuit just
killed any notion of using separate fuses per leg.... or
breakers without the ganged tie-bar. Dunno about my concept of
using BOTH a ganged 2 x pole breaker AND high speed fuses... one
fuse per hot leg... downstream of ganged 2 x pole breaker. IF
just ONE fuse popped open.. the other fuse would remain intact...
and the slower 2 x pole ganged breaker would remain intact....
the result being.. only one leg is opened off. Meanwhile, ur Dahl
plate xfmr loses power on primary..... until Joe ham... thinking
the power is OFF... gets in there...inside... grnds out one leg of
xfmr.... and ends up with 120 V fed to the 240 v primary...
resulting in 1/2 normal plate V, etc. With one hot leg still
intact [say it was 30-100A]... joe ham could still manage to
either electrocute himself... or melt stuff.

That being the case... and not being able to install fast fuses per
leg..... to protect a HV supply.... the only real option is a HV
fuse + glitch R. The best I can see for a 240 v primary... is
using "controlled magnetic hydraulic" breakers... with the 2 x
poles ganged together. Most of em come in different trip curve
ratings... so u want the FASTEST one possible.

I still can't find a half decent 100-A FAST magnetic breaker....
in any catalog.... haven't looked at all of em though.

FYI The base Alpha 77 wasn't UL approved. It had a hot ground

wire. There

was a higher cost version that had a step down transformer in it

if you

REQUIRED a two wire circuit. That's mentioned right in their

manual.

### amazing. IF one is going to the trbl of installing a new
240 V line to schack.... you may as well do it right the 1st
time... and install a 4 wire curcuit.

You are correct on all the other points. The separate CB's

wouldn't fly

today without a tied together gangbar to kill both sides of the AC

line.

A Grandfathered in system does not make it a good system. :-(

That's what I was referring to as CHEATING The System. Breaking

the

Electrical Code.

Since we are basically saying the same thing differently... We

have no

argument.

## agreed. I should obtain a copy of the latest code... since
mine is dated... I knew of SOME of the updates ... but not all....
like the new code sez all new homes must have arc detectors for
all bedrooms etc.

### In a lot of cases... if one is doing major updates on an
older home... they will want EXISTING... other stuff brought up
to new code standards.

### I dunno if AL conductor's are even allowed in homes
anymore. One home I had in the 80's had 12 ga AL wire...instead
of the usual 14 ga CU. I'm sure it was eventually banned. I
can see why. My son's bedroom duplex outlet ended up like charcoal
one day. The AL conductor's... doesn't matter how tight u crank
the screws.... always ends up going slack.. then u get a
resistance joint, etc. Pwr co's use exclusively AL conductor's
in the field... cuz of weight... and cost.

later.... Jim VE7RF

BOB DD