Just a few abstract thoughts here. It makes sense to me,
but then I've been known to over look the obvious on
occasion. ;-)

I have a solenoid coil that actuates a large 3-pole
contactor. A short pulse to pull up on a lever that
will toggle it from on position to another, and back.

Making measurements of the solenoid coil, although
potted in epoxy, yields a few measurements and a
couple of guesses.

http://www.pronine.ca/multind.htm

Coil form 1" diameter, 1-3/8" width and 1.5" depth.
Going backwards on a solenoid coil java script, yields
a matching 125 mH inductance (as measured) and 95 ohm
DCR (as measured) for 2500 turns of #30 AWG which will
fill the bobbin.

This a 480 VAC actuator.

Am I headed in the right direction if I assume the key
factor here is ampere turns?

Not allowing for the added inductance by a movable core,
this has an impedance of roughly 100 ohms. So that works
out to 4.8 amps or 12,000 ampere turns.

Substituting 2000 turns of #28 AWG yields 80 mH, and 42
Ohms. And subsequently roughly 12,000 ampere turns at
240 VAC.

Putting 240 VAC across the 480 VAC coil yields only 6,000
ampere turns and obviously is NOT enough to actuate the
contactor transfer mechanism.

The reason I'm curious is that ASCO seems to think that
the replacement coil for this is worth $585, although
they will sell it as the "sale price" of only $421.80.

Jeff-1.0
The other other one

--
"Everything from Crackers to Coffins"

Jeffrey Angus wrote:

Just a few abstract thoughts here. It makes sense to me,
but then I've been known to over look the obvious on
occasion. ;-)

I have a solenoid coil that actuates a large 3-pole
contactor. A short pulse to pull up on a lever that
will toggle it from on position to another, and back.

Making measurements of the solenoid coil, although
potted in epoxy, yields a few measurements and a
couple of guesses.

http://www.pronine.ca/multind.htm

Coil form 1" diameter, 1-3/8" width and 1.5" depth.
Going backwards on a solenoid coil java script, yields
a matching 125 mH inductance (as measured) and 95 ohm
DCR (as measured) for 2500 turns of #30 AWG which will
fill the bobbin.

This a 480 VAC actuator.

Am I headed in the right direction if I assume the key
factor here is ampere turns?

Not allowing for the added inductance by a movable core,
this has an impedance of roughly 100 ohms. So that works
out to 4.8 amps or 12,000 ampere turns.

Substituting 2000 turns of #28 AWG yields 80 mH, and 42
Ohms. And subsequently roughly 12,000 ampere turns at
240 VAC.

Putting 240 VAC across the 480 VAC coil yields only 6,000
ampere turns and obviously is NOT enough to actuate the
contactor transfer mechanism.

The reason I'm curious is that ASCO seems to think that
the replacement coil for this is worth $585, although
they will sell it as the "sale price" of only $421.80.

Jeff-1.0
The other other one

Beware that some coils are dual coils with diodes potted in them.

WHen a diode fails in one of these, they tend to generate some noise
when energized. This is because one coil is pushing both directions
against the other that isn't.

Basically what this means is, the coil is designed to operate in a
DC state.

What we have done in the past if we suspected a shorted diode in one
of these types is to put a bridge rectifier in front of it.

But I can tell you this, if the construction of core around this coil
in the device that is using it has a laminated type layers, chances are,
you have a simple coil and there is some form of shading device near the
contact point where the accouter makes contact with it.

What is this thing? A ratcheting three position device? being ASCO, it
sounds like some kind of valve.

Jamie

On Sun, 16 Oct 2011 15:48:07 -0500, Jeffrey Angus
wrote:

This a 480 VAC actuator.

Make, model, and photograph?

Is there a copper D-ring on the top end of the solenoid?

If the coil it dead, try disolving the epoxy.
http://www.esslinger.com/attack.aspx
It will also make a useful coil form.

If you know the core dimensions and the wire guage, you can estimate
the number of turns.

The reason I'm curious is that ASCO seems to think that
the replacement coil for this is worth $585, although
they will sell it as the "sale price" of only $421.80.

Check eBay?


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On 10/16/2011 4:33 PM, Jamie wrote:
Beware that some coils are dual coils with diodes potted in them.

WHen a diode fails in one of these, they tend to generate some noise
when energized. This is because one coil is pushing both directions
against the other that isn't.

Basically what this means is, the coil is designed to operate in a
DC state.

What we have done in the past if we suspected a shorted diode in one
of these types is to put a bridge rectifier in front of it.

But I can tell you this, if the construction of core around this coil
in the device that is using it has a laminated type layers, chances are,
you have a simple coil and there is some form of shading device near the
contact point where the accouter makes contact with it.

What is this thing? A ratcheting three position device? being ASCO, it
sounds like some kind of valve.

This is a simple multi-layer solenoid.
It is fed with 480 VAC via an external bridge rectifier.

It is a pull up actuated 100 amp 3-pole contactor.

It is physically identical to this one, with the excption of
being 3-poles rather than 2.

http://www.ebay.com/itm/130520617745

The solenoid is at the top left of the contactor with the bridge
rectifier on the side.

Jeff-1.0



--
"Everything from Crackers to Coffins"

On 10/16/2011 5:14 PM, Jeff Liebermann wrote:
On Sun, 16 Oct 2011 15:48:07 -0500, Jeffrey
wrote:

This a 480 VAC actuator.

Make, model, and photograph?


A similar model. 2-pole 120 VAC rather than 3-pole 480 VAC.
http://www.ebay.com/itm/130520617745

This is the coil itself from ASCO.
http://www.ascoparts.com/343500-063.html

Is there a copper D-ring on the top end of the solenoid?

Nope.

If the coil it dead, try disolving the epoxy.
http://www.esslinger.com/attack.aspx
It will also make a useful coil form.

Coil works perfectly with 480 VAC applied to the bridge
recitfier. My task is to wind a new coil that will work
at 240 VAC.

If you know the core dimensions and the wire gauge, you
can estimate the number of turns.

I did that, see the initial posting. Using DC resistance,
physical size and measured inductance.

The reason I'm curious is that ASCO seems to think that
the replacement coil for this is worth $585, although
they will sell it as the "sale price" of only $421.80.

Check eBay?

They have the contactors available from $750 and up, and
complete units for $1500 and up.

No solenoids only.

Jeff-1.0



--
"Everything from Crackers to Coffins"

On Oct 16, 1:48*pm, Jeffrey Angus wrote:
Just a few abstract thoughts here. It makes sense to me,
but then I've been known to over look the obvious on
occasion. ;-)

I have a solenoid coil that actuates a large 3-pole
contactor. A short pulse to pull up on a lever that
will toggle it from on position to another, and back.

Making measurements of the solenoid coil, although
potted in epoxy, yields a few measurements and a
couple of guesses.

http://www.pronine.ca/multind.htm

Coil form 1" diameter, 1-3/8" width and 1.5" depth.
Going backwards on a solenoid coil java script, yields
a matching 125 mH inductance (as measured) and 95 ohm
DCR (as measured) for 2500 turns of #30 AWG which will
fill the bobbin.

This a 480 VAC actuator.

Am I headed in the right direction if I assume the key
factor here is ampere turns?

Not allowing for the added inductance by a movable core,
this has an impedance of roughly 100 ohms. So that works
out to 4.8 amps or 12,000 ampere turns.

Substituting 2000 turns of #28 AWG yields 80 mH, and 42
Ohms. And subsequently roughly 12,000 ampere turns at
240 VAC.

Putting 240 VAC across the 480 VAC coil yields only 6,000
ampere turns and obviously is NOT enough to actuate the
contactor transfer mechanism.

The reason I'm curious is that ASCO seems to think that
the replacement coil for this is worth $585, although
they will sell it as the "sale price" of only $421.80.

do you see the part number on this list? Seems considerably cheaper:

http://www.valvestore.com/products.asp?dept=1448

Jamie wrote:

Jamie wrote:

Jeffrey Angus wrote:

On 10/16/2011 5:14 PM, Jeff Liebermann wrote:

On Sun, 16 Oct 2011 15:48:07 -0500, Jeffrey
wrote:

This a 480 VAC actuator.



Make, model, and photograph?




A similar model. 2-pole 120 VAC rather than 3-pole 480 VAC.
http://www.ebay.com/itm/130520617745

This is the coil itself from ASCO.
http://www.ascoparts.com/343500-063.html

Is there a copper D-ring on the top end of the solenoid?



Nope.

If the coil it dead, try disolving the epoxy.
http://www.esslinger.com/attack.aspx
It will also make a useful coil form.



Coil works perfectly with 480 VAC applied to the bridge
recitfier. My task is to wind a new coil that will work
at 240 VAC.

If you know the core dimensions and the wire gauge, you
can estimate the number of turns.



I did that, see the initial posting. Using DC resistance,
physical size and measured inductance.

The reason I'm curious is that ASCO seems to think that
the replacement coil for this is worth $585, although
they will sell it as the "sale price" of only $421.80.



Check eBay?



They have the contactors available from $750 and up, and
complete units for $1500 and up.

No solenoids only.

Jeff-1.0



Why don't you use a simple step up transformer for the coil?
you won't need a large one.

JAmie


To add to that, a 1:1 control transformer of a very small size can
be wired as a buck boost to operate that coil.


Tell him something he DOESN'T already know.


--
You can't have a sense of humor, if you have no sense.

Jeffrey Angus wrote:

On 10/16/2011 5:14 PM, Jeff Liebermann wrote:

On Sun, 16 Oct 2011 15:48:07 -0500, Jeffrey
wrote:

This a 480 VAC actuator.


Make, model, and photograph?



A similar model. 2-pole 120 VAC rather than 3-pole 480 VAC.
http://www.ebay.com/itm/130520617745

This is the coil itself from ASCO.
http://www.ascoparts.com/343500-063.html

Is there a copper D-ring on the top end of the solenoid?


Nope.

If the coil it dead, try disolving the epoxy.
http://www.esslinger.com/attack.aspx
It will also make a useful coil form.


Coil works perfectly with 480 VAC applied to the bridge
recitfier. My task is to wind a new coil that will work
at 240 VAC.

If you know the core dimensions and the wire gauge, you
can estimate the number of turns.


I did that, see the initial posting. Using DC resistance,
physical size and measured inductance.

The reason I'm curious is that ASCO seems to think that
the replacement coil for this is worth $585, although
they will sell it as the "sale price" of only $421.80.


Check eBay?


They have the contactors available from $750 and up, and
complete units for $1500 and up.

No solenoids only.

Jeff-1.0



Why don't you use a simple step up transformer for the coil?
you won't need a large one.

JAmie

Jamie wrote:

Jeffrey Angus wrote:

On 10/16/2011 5:14 PM, Jeff Liebermann wrote:

On Sun, 16 Oct 2011 15:48:07 -0500, Jeffrey
wrote:

This a 480 VAC actuator.



Make, model, and photograph?




A similar model. 2-pole 120 VAC rather than 3-pole 480 VAC.
http://www.ebay.com/itm/130520617745

This is the coil itself from ASCO.
http://www.ascoparts.com/343500-063.html

Is there a copper D-ring on the top end of the solenoid?



Nope.

If the coil it dead, try disolving the epoxy.
http://www.esslinger.com/attack.aspx
It will also make a useful coil form.



Coil works perfectly with 480 VAC applied to the bridge
recitfier. My task is to wind a new coil that will work
at 240 VAC.

If you know the core dimensions and the wire gauge, you
can estimate the number of turns.



I did that, see the initial posting. Using DC resistance,
physical size and measured inductance.

The reason I'm curious is that ASCO seems to think that
the replacement coil for this is worth $585, although
they will sell it as the "sale price" of only $421.80.



Check eBay?



They have the contactors available from $750 and up, and
complete units for $1500 and up.

No solenoids only.

Jeff-1.0



Why don't you use a simple step up transformer for the coil?
you won't need a large one.

JAmie


To add to that, a 1:1 control transformer of a very small size can
be wired as a buck boost to operate that coil.

Jamie

On 10/16/2011 8:05 PM, Jamie wrote:
Why don't you use a simple step up transformer for the coil?
you won't need a large one.

Um, however briefly, the transformer needs to supply
5.2 amps at 480 volts to successfully energize the coil.

That's 2500 VA Even a 500 VA control transformer that I have
sags too much to properly actuate the transfer switch.

Jeff-1.0

--
"Everything from Crackers to Coffins"

On 10/16/2011 8:12 PM, Jamie wrote:
To add to that, a 1:1 control transformer of a very small size
can be wired as a buck boost to operate that coil.

As I mentioned previously, the solenoid requires a 5.2 amp pulse
to properly actuate the contactor mechanism.

With a 240/240 control transformer wired up in boost mode that
would need at 1000 VA transformer as a bare minimum.

Jeff-1.0

--
"Everything from Crackers to Coffins"

On 10/16/2011 8:01 PM, Michael A. Terrell wrote:
Tell him something he DOESN'T already know.

Heh, thanks Michael. What I don't know and would like to
know is if my thinking with regards to ampere turns is
correct. Because I CAN wind a new solenoid coil with a
1/2 pound spool of wire for about $20.

Jeff-1.0

--
"Everything from Crackers to Coffins"

Jeffrey Angus wrote:

On 10/16/2011 8:05 PM, Jamie wrote:

Why don't you use a simple step up transformer for the coil?
you won't need a large one.


Um, however briefly, the transformer needs to supply
5.2 amps at 480 volts to successfully energize the coil.

That's 2500 VA Even a 500 VA control transformer that I have
sags too much to properly actuate the transfer switch.

Jeff-1.0

I find it hard to believe that coil is using that much? Are you
sure it's in proper working order? We have 500 amp contactors with
120V coils that only require about 2 amps to pull in. Something just
does not sound right, but what ever.



Jamie

On 10/16/2011 8:34 PM, Jamie wrote:
I find it hard to believe that coil is using that much? Are
you sure it's in proper working order? We have 500 amp
contactors with 120V coils that only require about 2 amps
to pull in. Something just does not sound right, but what
ever.

Yes I am sure. And yes I know what some contactors take to
actuate the coils in a steady state holding condition.

To repeat. This is a pulsed operation. The auxiliary contacts
on the transfer switch contactor interrupt the source from the
solenoid as it actuates.

The solenoid core pulls up on a link that rotates the armature
of the contactor assembly from normal to emergency position.
Each time it is pulsed, it rotates it one way, then the other
way.

The actual amount of time (I haven't measured it) this takes
is under a second roughly.

Jeff-1.0

--
"Everything from Crackers to Coffins"

Tell him something he DOESN'T already know.

Heh, thanks Michael. What I don't know and would like
to know is if my thinking with regards to ampere turns is
correct. Because I CAN wind a new solenoid coil with
a 1/2 pound spool of wire for about $20.

Do you have good reason to believe that AWG 30 is the proper gauge, and that
your calculations are correct? If so, then buy the wire and do it. If it
doesn't work, you're out only $20 and the time it took to wind the coil.

I don't know enough about solenoids to properly judge your calculations. But
I don't see anything obviously wrong.

Jeffrey Angus wrote:

On 10/16/2011 8:12 PM, Jamie wrote:

To add to that, a 1:1 control transformer of a very small size
can be wired as a buck boost to operate that coil.


As I mentioned previously, the solenoid requires a 5.2 amp pulse
to properly actuate the contactor mechanism.

With a 240/240 control transformer wired up in boost mode that
would need at 1000 VA transformer as a bare minimum.

Jeff-1.0

Then it must be pushing a large load a long distance.

at that current, you looks like you have ~ 100 ohm coil.

which means the wire in the coil is rather a large gauge since
this is DC going to it.

I would start around 20awg and see what the DCR 1M is on the
chart. Then see if that will physically fit on the form.


Jamie.

On 10/16/2011 8:44 PM, Jamie wrote:
Then it must be pushing a large load a long distance.

at that current, you looks like you have ~ 100 ohm coil

Did you read the details from my original posting? (Se below)

which means the wire in the coil is rather a large gauge since
this is DC going to it.

I would start around 20awg and see what the DCR 1M is on the
chart. Then see if that will physically fit on the form.

I originally wrote:
Coil form 1" diameter, 1-3/8" width and 1.5" depth.
Going backwards on a solenoid coil java script, yields
a matching 125 mH inductance (as measured) and 95 ohm
DCR (as measured) for 2500 turns of #30 AWG which will
fill the bobbin.

This a 480 VAC actuator.

roughly 100 ohms, yes.

This is NOT a constant pull and hold solenoid. This is a
pulsed operation.

So that works out to 4.8 amps or 12,000 ampere turns.

Substituting 2000 turns of #28 AWG yields 80 mH, and 42
Ohms. And subsequently roughly 12,000 ampere turns at
240 VAC.

Based on: Ampere turns =
(Applied voltage * number of turns)/(coil resistance)

Both estimations of the needed number of turns and wire size
seem correct.

Putting 240 VAC across the 480 VAC coil yields only 6,000
ampere turns and obviously is NOT enough to actuate the
contactor transfer mechanism.

This tends to indicate that ampere turns is indeed the magic
number as 6000 is not enough to actuate a mechanism that
appears to require 12,000.

Jeff-1.0

--
"Everything from Crackers to Coffins"

On 10/16/2011 8:42 PM, William Sommerwerck wrote:
Do you have good reason to believe that AWG 30 is the proper
gauge, and that your calculations are correct?

http://www.pronine.ca/multind.htm

Yields both the correct inductance and DC resistance with #30
AWG for the assumptions I've made for the physical size of the
coil bobbin.

If so, then buy the wire and do it. If it doesn't work, you're
out only $20 and the time it took to wind the coil.

I don't know enough about solenoids to properly judge your
calculations. But I don't see anything obviously wrong.

And that's why I thought I'd ask here. I was hoping to find
someone that _is_ familiar enough to at least tell me, "Yeah,
you seem to be heading in the right direction."

Jeff-1.0

--
"Everything from Crackers to Coffins"

On Oct 16, 6:59*pm, Jeffrey Angus wrote:
On 10/16/2011 8:42 PM, William Sommerwerck wrote:

Do you have good reason to believe that AWG 30 is the proper
gauge, and that your calculations are correct?

http://www.pronine.ca/multind.htm

Yields both the correct inductance and DC resistance with #30
AWG for the assumptions I've made for the physical size of the
coil bobbin.

If so, then buy the wire and do it. If it doesn't work, you're
out only $20 and the time it took to wind the coil.

I don't know enough about solenoids to properly judge your
calculations. But I don't see anything obviously wrong.

And that's why I thought I'd ask here. I was hoping to find
someone that _is_ familiar enough to at least tell me, "Yeah,
you seem to be heading in the right direction."


You didn't say this solenoid was part of a transfer switch. This
raises the stakes substantially. Transfer switches are used to switch
the mains supply to a generator when mains power is interrupted. They
serve two main purposes: to keep critical equipment functioning when
mains power is interrupted, and to deenergize the power line so that
workers can assume it is deenergized when they work on it.

Now, the transfer switch was tested to meet specifications with the
designed solenoid installed. Knowing nothing of the design or
construction of the component, you propose to roll your own and stick
it in.

Which would be fine, if no one's life depended on its working. And if
the vendor would stand behind your handicraft.

I don't think Asco could reasonably foresee that someone would use a
program that gives the number of turns for an air-core inductor to
design a part for a life-safety application.

On Sun, 16 Oct 2011 17:30:05 -0500, Jeffrey Angus
wrote:

Coil works perfectly with 480 VAC applied to the bridge
recitfier. My task is to wind a new coil that will work
at 240 VAC.

You left that out of your initial rant. First sentence should be what
the [deleted expletive] you're trying to accomplish.

I did that, see the initial posting. Using DC resistance,
physical size and measured inductance.

What you want is an equal amount of magnetic force (i.e. gilberts) or
ampere-turns for both the 480VAC and 240VAC coils.

480VAC coil = 125mH and 95 ohms
XL = 2*Pi*60*125*10^-3 = 47 ohm
Total impedance is the vector sum of 95 ohms and 47 ohms =
Z = sqrt(95^2 + 47^2) = 105 ohms
Current is:
I = 480VAC / 105 ohms = 4.5A
2500 turns * 4.5A = 11,250 AT
Ok, you got that part correct.

Trying a different gauge for 240VAC. The hard part will be keeping
the max diameter to under 1.5" OD.

http://www.pronine.ca/multind.htm
For #29awg, 75mH, 1990 turns, 51 ohms resistance.
XL = 2*Pi*60*75*10^-3 = 28 ohm
Z = sqrt(51^2 + 28^2) = 63 ohms
I = 240VAC / 63 ohms = 3.8A
1990 turns * 3.8A = 7580 AT

For #28awg, 60mH, 1759 turns, 37 ohms resistance.
XL = 2*Pi*60*60*10^-3 = 22.5 ohm
Z = sqrt(51^2 + 37^2) = 63 ohms
I = 240VAC / 63 ohms = 3.8A
1759 turns * 3.8A = 6700 AT

Ok, that's not going to work. Most of the impedance is coming from
the DC resistance of the wire. Decreasing the gauge decreases this
resistance, but also decreases the number of turns that will fit on a
the spool to a maximum OD of 1.5". This isn't working. I give up for
tonite.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On 10/16/2011 11:08 PM, spamtrap1888 wrote:
You didn't say this solenoid was part of a transfer switch. This
raises the stakes substantially. Transfer switches are used to switch
the mains supply to a generator when mains power is interrupted. They
serve two main purposes: to keep critical equipment functioning when
mains power is interrupted, and to deenergize the power line so that
workers can assume it is deenergized when they work on it.

Now, the transfer switch was tested to meet specifications with the
designed solenoid installed. Knowing nothing of the design or
construction of the component, you propose to roll your own and stick
it in.

Which would be fine, if no one's life depended on its working. And if
the vendor would stand behind your handicraft.

I don't think Asco could reasonably foresee that someone would use a
program that gives the number of turns for an air-core inductor to
design a part for a life-safety application.

Thank you for your information.

It changes nothing. The original solenoid develops about 12,000
ampere turns at 480 Volts. The replacement needs to develop 12,000
ampere turns at 240 volts.

If this were a customer, such as a extended care center where I
originally bought the used generator from and replaced their
original automatic transfer switch with a new compatible one I
would have (and did) take proper steps to insure everything worked
within the confines of a life-safety application.

This is a manual transfer switch with some control logic to determine
if all the power is present prior to switching. What in essence it
does is not allowing you to switch to a non-existent source.

I asked for an opinion that ampere turns was the right direction I
was headed in to change an operating solenoid from 480 to 240 volts.

I did not ask form someone such as yourself to presume that I totally
lack the ethics to endanger life with a crap modification.

Ya know, the way this transfer switch operates, I can just as easily
add the optional "manual handle" on the side of the box to switch from
normal to emergency power and throw away all the complicated stuff
inside.

As far as life safety is concerned, this is to handle a loss of power
at the shop I operate. Simple. "The power failed." Go outside, start
the generator and once it's running go back and flip the transfer
switch. When the utility power returns and stays on, flip the siwtch
aback and then go outside and turn the generator off.

This really isn't rocket science.

Jeff-1.0

--
"Everything from Crackers to Coffins"

On 10/16/2011 11:11 PM, Jeff Liebermann wrote:
Ok, that's not going to work. Most of the impedance is coming from
the DC resistance of the wire. Decreasing the gauge decreases this
resistance, but also decreases the number of turns that will fit on a
the spool to a maximum OD of 1.5". This isn't working. I give up for
tonite.

Well as long as your bitching at me for leaving something out....

The original coil is being fed through a bridge rectifier (mentioned
elsewhere in the thread). So the AC impedance is less of an issue.

Using the proline scripting, I came up with 80 mH using #28 AWG wire,
1988 turns and 1.54" outside diameter with 42.63 ohms.

I come up with 11192 ampere turns. I've got some wiggle room to
increase the bobbin size a bit. So rest well good sir, we are at
a point that is "close enough" to wind up a prototype and see if
works properly.

If it does, then it gets potted in Epoxy to match the original
physical dimensions and we call it a success.

Jeff-1.0

--
"Everything from Crackers to Coffins"

On Mon, 17 Oct 2011 02:51:21 -0500, Jeffrey Angus
wrote:

On 10/16/2011 11:11 PM, Jeff Liebermann wrote:
Ok, that's not going to work. Most of the impedance is coming from
the DC resistance of the wire. Decreasing the gauge decreases this
resistance, but also decreases the number of turns that will fit on a
the spool to a maximum OD of 1.5". This isn't working. I give up for
tonite.

Well as long as your bitching at me for leaving something out....

I always find something to complain about. It's part of my standard
usenet protocol. Nothing personal.

The original coil is being fed through a bridge rectifier (mentioned
elsewhere in the thread). So the AC impedance is less of an issue.

Bad news. 60Hz is still AC. The AC current, is determined by the AC
impedance also known as Z. Fortunately, most of it comes from the
resistance of the wires, making the coil specs easier to guess.

Using the proline scripting, I came up with 80 mH using #28 AWG wire,
1988 turns and 1.54" outside diameter with 42.63 ohms.

You cheated by going over the OD by 0.04". Assuming you can pack the
windings in as tight as the original, that shouldn't be a problem. I'm
not all that confident you can do it. Use a mandrel and a slow
turning lathe.

I come up with 11192 ampere turns. I've got some wiggle room to
increase the bobbin size a bit. So rest well good sir, we are at
a point that is "close enough" to wind up a prototype and see if
works properly.

It will probably work. I just hate to say that as I'm sure you'll
blame me when it explodes and sprays coil bobbin parts all over the
shop. It might help to immolate an old solenoid on the barbeque as a
burnt offering to the god of electric power for a favorable outcome.

If it does, then it gets potted in Epoxy to match the original
physical dimensions and we call it a success.

Right. Hide the evidence. Be sure to embalm the windings in yellow
Kapton (Polyimide) high temp tape before potting. I learned that the
hard way after trying to pot some radios. The epoxy shrinks as it
hardens, which likes to tear wires away from their attachment points.
The tape provides an easy air space for the epoxy to shrink.





--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On 10/17/2011 10:37 AM, Jeff Liebermann wrote:
I always find something to complain about. It's part of my standard
usenet protocol. Nothing personal.

Well of course, I've known you long enough now to fully understand
the protocol. ;-)

You cheated by going over the OD by 0.04". Assuming you can pack the
windings in as tight as the original, that shouldn't be a problem. I'm
not all that confident you can do it. Use a mandrel and a slow
turning lathe.

The physical demisions after the epoxy potting are 1.55, instead of
my guess of 1.375), and 1.66 rather than my also guess of of 1.50.

It will probably work. I just hate to say that as I'm sure you'll
blame me when it explodes and sprays coil bobbin parts all over the
shop.

Isn't that also standard Usenet protocol?

Right. Hide the evidence. Be sure to embalm the windings in yellow
Kapton (Polyimide) high temp tape before potting.

I still have several rolls here at the shop from when I'd rewind
surplus wall warts for laughs.

Jeff-1.0
the other other one.

Having a vacuum pot and temperature chamber helps make stuff
"right" when you do it. I kind of prefer a polyurethane for
potting myself.

--
"Everything from Crackers to Coffins"

On Mon, 17 Oct 2011 11:02:42 -0500, Jeffrey Angus
wrote:

Isn't that also standard Usenet protocol?

Yes. The first step to analyzing a failure is to blame someone.

Having a vacuum pot and temperature chamber helps make stuff
"right" when you do it. I kind of prefer a polyurethane for
potting myself.

I like to use Bondo, because it doesn't shrink.

Way back in the days when I still received a regular paycheck, the
company had a "modular products" division that sold data converters
into such non-critical applications like missiles and air traffic
control systems. Instead of just dumping the electronics into a
potting shell and filling it with epoxy, they would first fill it
almost to the pour hole with sand and then top it off with epoxy. The
thermal conductivity of epoxy is slightly better than lousy. The sand
gives an even temperature distribution, protects against mechanical
shock, and is cheaper than epoxy. It also makes post-potting repair
somewhat possible. Filling the bobbin with sand before potting isn't
going to do anything useful for your solenoid, but I thought I would
mention it for future applications.
--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Jeff Liebermann wrote:
On Mon, 17 Oct 2011 02:51:21 -0500, Jeffrey Angus
wrote:

On 10/16/2011 11:11 PM, Jeff Liebermann wrote:
Ok, that's not going to work. Most of the impedance is coming from
the DC resistance of the wire. Decreasing the gauge decreases this
resistance, but also decreases the number of turns that will fit on
a the spool to a maximum OD of 1.5". This isn't working. I give
up for tonite.

Well as long as your bitching at me for leaving something out....

I always find something to complain about. It's part of my standard
usenet protocol. Nothing personal.

The original coil is being fed through a bridge rectifier (mentioned
elsewhere in the thread). So the AC impedance is less of an issue.

Bad news. 60Hz is still AC. The AC current, is determined by the AC
impedance also known as Z. Fortunately, most of it comes from the
resistance of the wires, making the coil specs easier to guess.

Using the proline scripting, I came up with 80 mH using #28 AWG wire,
1988 turns and 1.54" outside diameter with 42.63 ohms.

You cheated by going over the OD by 0.04". Assuming you can pack the
windings in as tight as the original, that shouldn't be a problem. I'm
not all that confident you can do it. Use a mandrel and a slow
turning lathe.

I come up with 11192 ampere turns. I've got some wiggle room to
increase the bobbin size a bit. So rest well good sir, we are at
a point that is "close enough" to wind up a prototype and see if
works properly.

It will probably work. I just hate to say that as I'm sure you'll
blame me when it explodes and sprays coil bobbin parts all over the
shop. It might help to immolate an old solenoid on the barbeque as a
burnt offering to the god of electric power for a favorable outcome.

If it does, then it gets potted in Epoxy to match the original
physical dimensions and we call it a success.

Right. Hide the evidence. Be sure to embalm the windings in yellow
Kapton (Polyimide) high temp tape before potting. I learned that the
hard way after trying to pot some radios. The epoxy shrinks as it
hardens, which likes to tear wires away from their attachment points.
The tape provides an easy air space for the epoxy to shrink.

You said in an earlier post that the current in the coil needs to be around
5 amps, and you propose to use 28 AWG wire to wind it.
AWG 28 wire has a rated ampacity for chassis wiring (inside a bundle,
similar to your solenoid coil), is only 1.4 amps. I doubt that your coil
would last very long with that amount of current.
More investigation is necessary. Might be less painful to spring for the
proper solenoid from the manufacturer.
--
David
dgminala at mediacombb dot net

Dave M wrote:
Jeff Liebermann wrote:
On Mon, 17 Oct 2011 02:51:21 -0500, Jeffrey Angus
wrote:

On 10/16/2011 11:11 PM, Jeff Liebermann wrote:
Ok, that's not going to work. Most of the impedance is coming from
the DC resistance of the wire. Decreasing the gauge decreases this
resistance, but also decreases the number of turns that will fit on
a the spool to a maximum OD of 1.5". This isn't working. I give
up for tonite.

Well as long as your bitching at me for leaving something out....

I always find something to complain about. It's part of my standard
usenet protocol. Nothing personal.

The original coil is being fed through a bridge rectifier (mentioned
elsewhere in the thread). So the AC impedance is less of an issue.

Bad news. 60Hz is still AC. The AC current, is determined by the AC
impedance also known as Z. Fortunately, most of it comes from the
resistance of the wires, making the coil specs easier to guess.

Using the proline scripting, I came up with 80 mH using #28 AWG
wire, 1988 turns and 1.54" outside diameter with 42.63 ohms.

You cheated by going over the OD by 0.04". Assuming you can pack the
windings in as tight as the original, that shouldn't be a problem.
I'm not all that confident you can do it. Use a mandrel and a slow
turning lathe.

I come up with 11192 ampere turns. I've got some wiggle room to
increase the bobbin size a bit. So rest well good sir, we are at
a point that is "close enough" to wind up a prototype and see if
works properly.

It will probably work. I just hate to say that as I'm sure you'll
blame me when it explodes and sprays coil bobbin parts all over the
shop. It might help to immolate an old solenoid on the barbeque as a
burnt offering to the god of electric power for a favorable outcome.

If it does, then it gets potted in Epoxy to match the original
physical dimensions and we call it a success.

Right. Hide the evidence. Be sure to embalm the windings in yellow
Kapton (Polyimide) high temp tape before potting. I learned that the
hard way after trying to pot some radios. The epoxy shrinks as it
hardens, which likes to tear wires away from their attachment points.
The tape provides an easy air space for the epoxy to shrink.

You said in an earlier post that the current in the coil needs to be
around 5 amps, and you propose to use 28 AWG wire to wind it.
AWG 28 wire has a rated ampacity for chassis wiring (inside a bundle,
similar to your solenoid coil), is only 1.4 amps. I doubt that your
coil would last very long with that amount of current.
More investigation is necessary. Might be less painful to spring for
the proper solenoid from the manufacturer.


OOps.. I got that wrong.. That figure was the capacity in free air... The
capacity of AWG28 wire in an enclosed space is 0.83 amps.

--
David
dgminala at mediacombb dot net

On 10/17/2011 2:21 PM, Dave M wrote:
You said in an earlier post that the current in the coil needs to be
around 5 amps, and you propose to use 28 AWG wire to wind it.
AWG 28 wire has a rated ampacity for chassis wiring (inside a bundle,
similar to your solenoid coil), is only 1.4 amps. I doubt that your
coil would last very long with that amount of current.
More investigation is necessary. Might be less painful to spring for
the proper solenoid from the manufacturer.

OOps.. I got that wrong.. That figure was the capacity in free air... The
capacity of AWG28 wire in an enclosed space is 0.83 amps.

I'm sure that it is. The original coil at 480 volts draws 5.2 amps
and is wounnd with #30 AWG.

Guess I need to repeat this. It is PULSED not STEADY operation.

Jeff-1.0

--
"Everything from Crackers to Coffins"

Jeffrey Angus wrote:
On 10/16/2011 11:11 PM, Jeff Liebermann wrote:

Ok, that's not going to work. Most of the impedance is coming from
the DC resistance of the wire. Decreasing the gauge decreases this
resistance, but also decreases the number of turns that will fit on a
the spool to a maximum OD of 1.5". This isn't working. I give up for
tonite.


Well as long as your bitching at me for leaving something out....

The original coil is being fed through a bridge rectifier (mentioned
elsewhere in the thread). So the AC impedance is less of an issue.

Using the proline scripting, I came up with 80 mH using #28 AWG wire,
1988 turns and 1.54" outside diameter with 42.63 ohms.

I come up with 11192 ampere turns. I've got some wiggle room to
increase the bobbin size a bit. So rest well good sir, we are at
a point that is "close enough" to wind up a prototype and see if
works properly.

If it does, then it gets potted in Epoxy to match the original
physical dimensions and we call it a success.

Jeff-1.0

You know, at this point, you pretty much don't care I would assume how
ever, have you thought about constructing a voltage double rectifier
instead of that bridge rectifier to drive that coil?





+-------+-------++
| | |
+ | |
D1 - | |
^ | |
| | +
C1 + + C|
240 AC in | --- C| 480 Solenoid
|| | ---C2 C|
+---+-||+------+ + |
|| + | +
| | |
- | |
D2 ^ | |
240 AC in + | |
| + |
+-------------+-------++-------+
(created by AACircuit v1.28.6 beta 04/19/05 www.tech-chat.de)


I suppose if you had to motor caps around you could use those, the
large ones of course.

What ever.
Jamie

On Mon, 17 Oct 2011 19:05:15 -0400, Jamie
t wrote:

You know, at this point, you pretty much don't care I would assume how
ever, have you thought about constructing a voltage double rectifier
instead of that bridge rectifier to drive that coil?





+-------+-------++
| | |
+ | |
D1 - | |
^ | |
| | +
C1 + + C|
240 AC in | --- C| 480 Solenoid
|| | ---C2 C|
+---+-||+------+ + |
|| + | +
| | |
- | |
D2 ^ | |
240 AC in + | |
| + |
+-------------+-------++-------+
(created by AACircuit v1.28.6 beta 04/19/05 www.tech-chat.de)


I suppose if you had to motor caps around you could use those, the
large ones of course.

What ever.
Jamie

Good idea. The caps will need to be charged by the 240VAC line
voltage in a few cycles in order to get any kind of usable response
time for pulsed operation. That means the caps are going to be rather
big. A rough guess would be:

AC impedance of the coil is roughly:
480VAC / 5A = 96 ohms
To get C2 up to about 90% of full charge in 2 cycles, the capacitive
reactance of C1 would need to be about:
Xc = 96 * 0.1 = 9.6 ohms
At 60Hz, that's 276 uF. 330uf 600VDC caps should work. I'm not very
confident with my crude approximations. Therefore, I would feed the
model to LTSpice and see what it's really going to do.


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On 10/18/2011 11:47 AM, Jeff Liebermann wrote:
At 60Hz, that's 276 uF. 330uf 600VDC caps should work. I'm not very
confident with my crude approximations. Therefore, I would feed the
model to LTSpice and see what it's really going to do.

You're charging to the peak values, not RMS, so it's going to be 680
volts at a minimum, and probably more like 750 for some margin of
safety.

Caps of that size and rating will end up costing as much as the coil
itself.

Jeff



--
"Everything from Crackers to Coffins"

On 10/17/2011 6:05 PM, Jamie wrote:

You know, at this point, you pretty much don't care

You're right. I don't. Because my original question was
in regards to ampere turns and rewinding a solenoid for
a different operating voltage.

Because so far, with one notable exception, everyone has
insisted on coming up with some Rube Goldberg solution or
accusing me of trying to murder widows and orphans.

Jeff-1.0

--
"Everything from Crackers to Coffins"

On Oct 19, 5:09*am, Jeffrey Angus wrote:
On 10/17/2011 6:05 PM, Jamie wrote:



You know, at this point, you pretty much don't care

You're right. I don't. Because my original question was
in regards to ampere turns and rewinding a solenoid for
a different operating voltage.

I wish that that had been your original question, which was a rambling
stream of consciousness. Your reference to a program for calculating
aircore inductors made me think you were using "solenoid" in the sense
of "helical coil."


Because so far, with one notable exception, everyone has
insisted on coming up with some Rube Goldberg solution or
accusing me of trying to murder widows and orphans.


Your desire to save $380 in the belief that ASCO was screwing its
customers with jacked-up prices seemed a bit unreasonable, the more so
when you revealed the true application for the solenoid actuator.

But your juryrig would merely produce widows and orphans, not kill
them. Only the lineman trying to restore power would be killed if your
Rube Goldberg solution failed to work.

spamtrap1888 wrote:

Your desire to save $380 in the belief that ASCO was screwing its
customers with jacked-up prices seemed a bit unreasonable, the more so
when you revealed the true application for the solenoid actuator.

But your juryrig would merely produce widows and orphans, not kill
them. Only the lineman trying to restore power would be killed if your
Rube Goldberg solution failed to work.


Can't follow a thread, can you? It's for his workshop.


--
You can't have a sense of humor, if you have no sense.

On 10/19/2011 10:52 AM, spamtrap1888 wrote:
But your juryrig would merely produce widows and orphans, not kill
them. Only the lineman trying to restore power would be killed if your
Rube Goldberg solution failed to work.

Since you seem to be so good at divination....Pray tell me just
exactly how a three-pole double throw transfer switch can connect
the emergency power to the line rather than the load.

The ONLY thing this switch can do if the solenoid fails is to NOT
actuate the switch from one position the other.

But I'm sure you have a reasonable explanation on how that can
not be the case here.

Jeff-1.0


--
"Everything from Crackers to Coffins"

spamtrap1888 wrote:
On Oct 19, 5:09 am, Jeffrey Angus wrote:

On 10/17/2011 6:05 PM, Jamie wrote:




You know, at this point, you pretty much don't care

You're right. I don't. Because my original question was
in regards to ampere turns and rewinding a solenoid for
a different operating voltage.


I wish that that had been your original question, which was a rambling
stream of consciousness. Your reference to a program for calculating
aircore inductors made me think you were using "solenoid" in the sense
of "helical coil."


Because so far, with one notable exception, everyone has
insisted on coming up with some Rube Goldberg solution or
accusing me of trying to murder widows and orphans.



Your desire to save $380 in the belief that ASCO was screwing its
customers with jacked-up prices seemed a bit unreasonable, the more so
when you revealed the true application for the solenoid actuator.

But your juryrig would merely produce widows and orphans, not kill
them. Only the lineman trying to restore power would be killed if your
Rube Goldberg solution failed to work.
I must say, you are an idiot!

How is the device itself any less dangerous than using an alternate to
operate it?

Jamie

On Oct 19, 2:47*pm, Jeffrey Angus wrote:
On 10/19/2011 10:52 AM, spamtrap1888 wrote:

But your juryrig would merely produce widows and orphans, not kill
them. Only the lineman trying to restore power would be killed if your
Rube Goldberg solution failed to work.

Since you seem to be so good at divination....Pray tell me just
exactly how a three-pole double throw transfer switch can connect
the emergency power to the line rather than the load.

The ONLY thing this switch can do if the solenoid fails is to NOT
actuate the switch from one position the other.

But I'm sure you have a reasonable explanation on how that can
not be the case here.


I see that only the ASCO 4000 and 7000 series are closed-transition
switches, i.e. break before make, not the Series 940 -- which I had to
look up from the replacement part number you gave.

My bad, I suppose.

On Oct 19, 3:14*pm, Jamie
t wrote:
spamtrap1888 wrote:
On Oct 19, 5:09 am, Jeffrey Angus wrote:

On 10/17/2011 6:05 PM, Jamie wrote:

You know, at this point, you pretty much don't care

You're right. I don't. Because my original question was
in regards to ampere turns and rewinding a solenoid for
a different operating voltage.

I wish that that had been your original question, which was a rambling
stream of consciousness. Your reference to a program for calculating
aircore inductors made me think you were using "solenoid" in the sense
of "helical coil."

Because so far, with one notable exception, everyone has
insisted on coming up with some Rube Goldberg solution or
accusing me of trying to murder widows and orphans.

Your desire to save $380 in the belief that ASCO was screwing its
customers with jacked-up prices seemed a bit unreasonable, the more so
when you revealed the true application for the solenoid actuator.

But your juryrig would merely produce widows and orphans, not kill
them. Only the lineman trying to restore power would be killed if your
Rube Goldberg solution failed to work.

I must say, you are an idiot!

* How is the device itself any less dangerous than using an alternate to
operate it?

Jamie

If the alternate does not operate sufficiently like the original.

If he could explain how the actuator works and what the important
parameters were, we could speculate as to all the possible failure
modes.

spamtrap1888 wrote:
On Oct 19, 3:14 pm, Jamie
t wrote:

spamtrap1888 wrote:

On Oct 19, 5:09 am, Jeffrey Angus wrote:

On 10/17/2011 6:05 PM, Jamie wrote:

You know, at this point, you pretty much don't care

You're right. I don't. Because my original question was
in regards to ampere turns and rewinding a solenoid for
a different operating voltage.

I wish that that had been your original question, which was a rambling
stream of consciousness. Your reference to a program for calculating
aircore inductors made me think you were using "solenoid" in the sense
of "helical coil."

Because so far, with one notable exception, everyone has
insisted on coming up with some Rube Goldberg solution or
accusing me of trying to murder widows and orphans.

Your desire to save $380 in the belief that ASCO was screwing its
customers with jacked-up prices seemed a bit unreasonable, the more so
when you revealed the true application for the solenoid actuator.

But your juryrig would merely produce widows and orphans, not kill
them. Only the lineman trying to restore power would be killed if your
Rube Goldberg solution failed to work.

I must say, you are an idiot!

How is the device itself any less dangerous than using an alternate to
operate it?

Jamie


If the alternate does not operate sufficiently like the original.

If he could explain how the actuator works and what the important
parameters were, we could speculate as to all the possible failure
modes.
You can speculate all you want. You sound like an attorney looking for
work or closely related to one.

If you read the blog, you would see what he is using if for, and if
he really wants you to know, I am sure he'll refresh your memory.

Jamie

On 10/19/2011 8:39 PM, spamtrap1888 wrote:
I see that only the ASCO 4000 and 7000 series are closed-transition
switches, i.e. break before make, not the Series 940 -- which I had to
look up from the replacement part number you gave.

My bad, I suppose.

I suppose. The solenoid coil listed is for the series 940. It
is also used for several other series. Specifically, in my case,
the Series 386 manual transfer switch.

And in case you missed it earlier, here is the link for an eBay
auction showing picturs of the transfer switch contactor.

A similar model. 2-pole 120 VAC rather than 3-pole 480 VAC.
http://www.ebay.com/itm/130520617745

And if you go to the partsasco.com website and look up the replacement
part numbers for the model 300 or 386, it directs you to the coil
marked as being for the series 940.

This is the coil itself from ASCO.
http://www.ascoparts.com/343500-063.html

But again, you're making all sorts of asumption looking to find
fault. You've done nothing what so ever to answer the question
on rewinding a solenoid to operate at 240 volts rather than 480.

Jeff-1.0

--
"Everything from Crackers to Coffins"