3 Dec
2003
3 Dec
'03
4:48 p.m.
Hi,
I've got an electrolytic I pulled from my TU56 drive because it had a big
crusty electrolyte extrusion through the vent plug in the top. The
capacitor is marked "SPRAGUE 100 MFD 55V - 60CY A5030". It is 2" in
diameter and just over 4" tall, with two solder lugs on top. I think they
are connected to the drive motors.
I have looked for replacement electrolytic, but they all have way more
capacitance or way more voltage rating, and are nowhere near the right
physical dimensions. Is there a source for exact replacements?
If not, should I just get one with the right diameter for the mounting clamp
and the right capacitance, but some huge voltage rating, or is the voltage
rating more important and I should beef up the capacitance instead? Or do I
have to get both those right, and substitute a little dinky device?
Thanks!
Vince
3 Dec
3 Dec
6:05 p.m.
On Wed, Dec 03, 2003 at 10:48:35PM -0800, vrs wrote:
Hi,
I've got an electrolytic I pulled from my TU56 drive because it had a big
crusty electrolyte extrusion through the vent plug in the top.
Ewwww.
.... "SPRAGUE 100 MFD 55V - 60CY A5030". It
is 2" in diameter and just
over 4" tall, with two solder lugs on top. I think they are connected to
the drive motors.
Yes. The motor start capacitors.
I have looked for replacement electrolytic, but they
all have way more
capacitance or way more voltage rating, and are nowhere near the right
physical dimensions.
Voltages that are "too high" are no problem. Too low is a big no-no. You
want something with a fairly close capacitance match, because too little
would probably increase the startup time on the motor and might cause issues
if too far off.
Is there a source for exact replacements?
Not that I am aware of.
There are others (David Gesswein?) who have had to replace TU-56 motor caps.
I have not yet had to do so (but it's been years since I fired mine up, since
I've only recently repaird my -8/e PSU). My personal priority would have to
be voltage and capacitance over physical size.
A caveat - these are not filter caps. They are motor start caps (or they
might be "motor run" caps. They will be hard to find an appropriate sub
for.
-ethan
--
Ethan Dicks, A-130-S Current South Pole Weather at 04-Dec-2003 08:00 Z
South Pole Station
PSC 468 Box 400 Temp -17.7 F (-27.6 C) Windchill -53.2 F (-47.4 C)
APO AP 96598 Wind 12 kts Grid 082 Barometer 692.8 mb (10147. ft)
Ethan.Dicks(a)amanda.spole.gov http://penguincentral.com/penguincentral.html
7:58 p.m.
New subject: PDP11/24 M7133 / KDF11-UA Documentation
Hello all,
as I posted to alt.sys.pdp11 already I've some problems to find the
console connection to my KDF11-UA (11/24 CPU) board..
I don't want to repost my message here, but here are the boards in the
cpu box:
M7133
M7134
M7891
M9202
M9302
TWH DR11B / Tewidata
TWH DZ11 / Tewidata
Plessey-Board, DR11C
Sure I know, that I shouldn't try to search for a console connector on
the following boards:
One Emulex SMD Controller SC1210201-CXD
TWH KW11-P Realtime Clock / Tewidata
one AD/DA-Board from ADAC
Pete Turnbull kindly gave me the hint to search for the SLU-conenctors
on the M7133 board already, so I've learned, that there should be two
connectors, which are simply missing on my board. They are not soldered,
if I'm correctly interpreting the layout of my board.
I think I have to solder these connectors by my own?
Is there any documentation of this board online? I didn't find any
documentation on Al Kossow's site.
Andreas
11:08 p.m.
Voltages that are "too high" are no problem.
Too low is a big no-no. You
want something with a fairly close capacitance match, because too little
would probably increase the startup time on the motor and might cause
issues
if too far off.
There are others (David Gesswein?) who have had to
replace TU-56 motor
caps.
I have not yet had to do so (but it's been years
since I fired mine up,
since
I've only recently repaird my -8/e PSU). My
personal priority would have
to
be voltage and capacitance over physical size.
This matched my intuition, but I didn't know enough about the chemistry of
electrolytics to be sure it was OK to run them significantly below their
rated voltage. There appear to be cans available that get the capacitance
and diameter right (so would be easy to mount), but have 4x or 8x the
voltage rating. They are only a couple inches tall, but that isn't a
problem.
A caveat - these are not filter caps. They are motor
start caps (or they
might be "motor run" caps. They will be hard to find an appropriate sub
for.
I thought filter caps went for large capacitances, whereas motor start caps
tended toward high voltages. Are there other differences?
Thanks!
Vince
4 Dec
4 Dec
2:18 a.m.
On Thu, 2003-12-04 at 05:08, vrs wrote:
The capacitors you're talking about are the "motor run" capacitors for
the motors. There is a difference between them and motor start
capacitors. Motor start capacitors (as the name implies) are used for
starting (large HP) AC motors. They create a phase shift in the current
across the windings so that the motor will actually start. They are
intended to be used only while the motor is starting rotation. I'm less
clear about motor run capacitors, but they are used while the motor is
in operation. In either case they are definitely *not* polarized.
--
TTFN - Guy
A caveat - these are not filter caps. They are
motor start caps (or they
might be "motor run" caps. They will be hard to find an appropriate sub
for.
I thought filter caps went for large capacitances, whereas motor start caps
tended toward high voltages. Are there other differences?
4:23 a.m.
The capacitors you're talking about are the
"motor run" capacitors for
the motors. There is a difference between them and motor start
capacitors. Motor start capacitors (as the name implies) are used for
starting (large HP) AC motors. They create a phase shift in the current
across the windings so that the motor will actually start. They are
intended to be used only while the motor is starting rotation. I'm less
clear about motor run capacitors, but they are used while the motor is
in operation. In either case they are definitely *not* polarized.
Here is my problem with the claim that a couple of people have made, that
these are "motor run" caps: They are clearly filled with paste, not oil (as
some has been forced out through the emergency vent hole), and they seem to
be marked with a "-" near one of the solder lugs. That strongly suggests to
me that these are electrolytic "motor start" capacitors.
Am I missing something?
Vince
9:53 a.m.
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3 Dec
3 Dec
11:28 p.m.
Motor Start or Motor Run capacitors can be hard to find. Even the
companies tht deal with motors and pumps don't ususually carry them.
Fortunately there's a surplus company (Skycraft) here in town (Orlando)
that carries lots of this kind of stuff. If you send me an E-mail with the
dimensions and how it mounts I'll see what I can find.
Joe
At 03:05 AM 12/4/03 -0500, you wrote:
On Wed, Dec 03, 2003 at 10:48:35PM -0800, vrs wrote:
(-47.4 C)
Hi,
I've got an electrolytic I pulled from my TU56 drive because it had a big
crusty electrolyte extrusion through the vent plug in the top.
Ewwww.
.... "SPRAGUE 100 MFD 55V - 60CY
A5030". It is 2" in diameter and just
over 4" tall, with two solder lugs on top. I think they are connected to
the drive motors.
Yes. The motor start capacitors.
I have looked for replacement electrolytic, but
they all have way more
capacitance or way more voltage rating, and are nowhere near the right
physical dimensions.
Voltages that are "too high" are no problem. Too low is a big no-no. You
want something with a fairly close capacitance match, because too little
would probably increase the startup time on the motor and might cause issues
if too far off.
Is there a source for exact replacements?
Not that I am aware of.
There are others (David Gesswein?) who have had to replace TU-56 motor caps.
I have not yet had to do so (but it's been years since I fired mine up, since
I've only recently repaird my -8/e PSU). My personal priority would have to
be voltage and capacitance over physical size.
A caveat - these are not filter caps. They are motor start caps (or they
might be "motor run" caps. They will be hard to find an appropriate sub
for.
-ethan
--
Ethan Dicks, A-130-S Current South Pole Weather at 04-Dec-2003 08:00 Z
South Pole Station
PSC 468 Box 400 Temp -17.7 F (-27.6 C) Windchill -53.2 F APO AP 96598 Wind 12 kts Grid 082
Barometer 692.8 mb (10147.
ft)
Ethan.Dicks(a)amanda.spole.gov
http://penguincentral.com/penguincentral.html
4 Dec
4 Dec
9:23 a.m.
On Thu, 4 Dec 2003, Joe wrote:
Motor Start or Motor Run capacitors can be hard to
find. Even the
companies tht deal with motors and pumps don't ususually carry them.
Fortunately there's a surplus company (Skycraft) here in town (Orlando)
that carries lots of this kind of stuff. If you send me an E-mail with the
dimensions and how it mounts I'll see what I can find.
Joe
Motor start/run capacitors are pretty commonly available at stores
which deal in parts for the appliance an heating & ventilating
trades. They may not be the same size as yours was, and will
likely have spade lug contacts vice soldered, but I'd bet that you
can find something of a suitable rating.
- don
At 03:05 AM 12/4/03 -0500, you wrote:
On Wed, Dec 03, 2003 at 10:48:35PM -0800, vrs
wrote:
(-47.4 C)
Hi,
I've got an electrolytic I pulled from my TU56 drive because it had a big
crusty electrolyte extrusion through the vent plug in the top.
Ewwww.
.... "SPRAGUE 100 MFD 55V - 60CY
A5030". It is 2" in diameter and just
over 4" tall, with two solder lugs on top. I think they are connected to
the drive motors.
Yes. The motor start capacitors.
I have looked for replacement electrolytic, but
they all have way more
capacitance or way more voltage rating, and are nowhere near the right
physical dimensions.
Voltages that are "too high" are no problem. Too low is a big no-no. You
want something with a fairly close capacitance match, because too little
would probably increase the startup time on the motor and might cause issues
if too far off.
Is there a source for exact replacements?
Not that I am aware of.
There are others (David Gesswein?) who have had to replace TU-56 motor caps.
I have not yet had to do so (but it's been years since I fired mine up, since
I've only recently repaird my -8/e PSU). My personal priority would have to
be voltage and capacitance over physical size.
A caveat - these are not filter caps. They are motor start caps (or they
might be "motor run" caps. They will be hard to find an appropriate sub
for.
-ethan
--
Ethan Dicks, A-130-S Current South Pole Weather at 04-Dec-2003 08:00 Z
South Pole Station
PSC 468 Box 400 Temp -17.7 F (-27.6 C) Windchill -53.2 F APO AP 96598 Wind 12 kts Grid 082
Barometer 692.8 mb (10147.
ft)
Ethan.Dicks(a)amanda.spole.gov
http://penguincentral.com/penguincentral.html
3 Dec
3 Dec
6:08 p.m.
New subject: SV: 100MFD 55V
Hi,
These are oilfilled AC capacitors. Not an electrolytic capacitor. They are
usually used together with the motor. Phase-shift capacitor for example to
generate a second phase on a single phase system.
Do no replace with an electrolytic capacitor. Electrolytic capacitors are DC
only.
Old DEC equipment contain a lot of them. It is not uncommon to find such
capacitors with PCB (Polyclorinathed Bifenyles, if my speeling is correct)
in them. Take care if one of these goes into smoke. Burnt PCB produces
really lethal dioxines.
/Mattis
-----Ursprungligt meddelande-----
Fr?n: cctalk-bounces(a)classiccmp.org
[mailto:cctalk-bounces@classiccmp.org]F?r vrs
Skickat: den 4 december 2003 07:49
Till: General Discussion: On-Topic and Off-Topic Posts
?mne: 100MFD 55V
Hi,
I've got an electrolytic I pulled from my TU56 drive because it had a big
crusty electrolyte extrusion through the vent plug in the top. The
capacitor is marked "SPRAGUE 100 MFD 55V - 60CY A5030". It is 2" in
diameter and just over 4" tall, with two solder lugs on top. I think they
are connected to the drive motors.
I have looked for replacement electrolytic, but they all have way more
capacitance or way more voltage rating, and are nowhere near the right
physical dimensions. Is there a source for exact replacements?
If not, should I just get one with the right diameter for the mounting clamp
and the right capacitance, but some huge voltage rating, or is the voltage
rating more important and I should beef up the capacitance instead? Or do I
have to get both those right, and substitute a little dinky device?
Thanks!
Vince
10:59 p.m.
These are oilfilled AC capacitors. Not an electrolytic
capacitor. They are
usually used together with the motor. Phase-shift capacitor for example to
generate a second phase on a single phase system.
Do no replace with an electrolytic capacitor. Electrolytic capacitors are
DC
only.
Old DEC equipment contain a lot of them. It is not uncommon to find such
capacitors with PCB (Polyclorinathed Bifenyles, if my speeling is correct)
in them. Take care if one of these goes into smoke. Burnt PCB produces
really lethal dioxines.
Hmm...Doesn't look oil-filled to me; more like a cream-colored paste. Looks
just like an electrolytic which has blown crud out through the safety vent,
which has then hardened over the years into a crust. Under the crust is a
cream-colored substance with a texture like hardened toothpaste.
I do know that motor start and motor run are different and incompatible.
This one is connected to the coils driven by a G848, if I understand the
TU56 drawings correctly. The G848 drawing shows it being driven
bi-directionally to "motor supply", so you could be right about it not being
polarized, though I also thought I read a faint "-" next to one of the
solder tabs.
How would I tell the difference between a motor-run and a motor-start cap by
looking?
Thanks!
Vince
4 Dec
4 Dec
9:44 a.m.
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11:43 a.m.
----- Original Message -----
From: "Tony Duell" <ard(a)p850ug1.demon.co.uk>
To: <cctalk(a)classiccmp.org>
Sent: Friday, December 05, 2003 10:14 AM
Subject: Re: 100MFD 55V
> Hmm...Doesn't look oil-filled to me; more
like a cream-colored paste.
Looks
> just like an electrolytic which has blown crud
out through the safety
vent,
I beleive these are non-polarised electrolytics....
Certainly are. Sanyo TV's have a couple that frequently fail and need
replacement.
You *can* cobble one up by joining two conventional electros of the same
value cathode to cathode which makes a single non polarised electro with
half the value of the sum of the two. (Caps in series)
My experience has been that such cobbled up versions tend to fail after
about
12 months or so but it's useful if you need a quick fix.
Geoff in Oz
1:28 p.m.
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6 Dec
6 Dec
1:11 p.m.
New subject: 100MFD 55V (been there done that)
Some time ago I found a replacement for the motor run caps for a TU-56. They
are definitely motor run caps that you need. The replacements are slightly
offsize and require a different mounting bracket.
These caps are $140 each as I recall, perhaps $70 - because I can't remember
if the price I got was for one or two. I am however, quite sure they are the
correct replacement for the motor run caps in the TU-56.
If you haven't found the replacements, let me know and I'll dig up the
info - supplier, cost, etc.
Jay West
----- Original Message -----
From: "Tony Duell" <ard(a)p850ug1.demon.co.uk>
To: <cctalk(a)classiccmp.org>
Sent: Thursday, December 04, 2003 9:28 PM
Subject: Re: 100MFD 55V
Sure. I believe that's how some (all?) non-polarised electrolytic
capacitors are made. But you want the 2 halves to be closely matched --
possible if you're making them together (i.e. you're the manufacturer
making a non-polarised electrolytic), but not so likely if you're just
connecting 2 caps in series. That's probably why the homebrew version has
a short life.
-tony
I beleive these are non-polarised electrolytics....
Certainly are. Sanyo TV's have a couple that frequently fail and need
replacement.
You *can* cobble one up by joining two conventional electros of the same
value cathode to cathode which makes a single non polarised electro with
half the value of the sum of the two. (Caps in series)
1:48 p.m.
New subject: 100MFD 55V (been there done that)
Some time ago I found a replacement for the motor run
caps for a TU-56.
They
are definitely motor run caps that you need. The
replacements are slightly
offsize and require a different mounting bracket.
These caps are $140 each as I recall, perhaps $70 - because I can't
remember
if the price I got was for one or two. I am however,
quite sure they are
the
correct replacement for the motor run caps in the
TU-56.
Yikes! No wonder people wire electrolytics back-to-back :-)! I was hoping
to go shopping for a new set of these on Monday. Maybe I'll be buying less
than all four :-).
Vince
4 Dec
4 Dec
9:36 a.m.
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16 comments
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ard＠p850ug1.demon.co.uk -
asholz＠topinform.com -
dickset＠amanda.spole.gov -
donm＠cts.com -
geoffrob＠stmarks.pp.catholic.edu.au -
ggs＠shiresoft.com -
jwest＠classiccmp.org -
mattis＠mattisborgen.org -
rigdonj＠cfl.rr.com -
vrs＠msn.com