Testing a washing machine capacitor

[Craig]

I have a 67uf 220V washing machine capacitor that I would like to see if
it works. How can I test it without a capacitance meter?

Thanks.

 

[Justin Thyme]

stick it across 240V momentarily, then hold onto the connectors. if you
light up like a christmas tree you know it works.
Seriously... if you have a LED and a resistor of about 300-500ohms, you
should be able to connect it across a 12V battery as follows -
BatteryTerminal--Resistor--Led--Cap--BattTerm
You should see the led light brightly for a short period then fairly quickly
fade out. Then get your resistor and Led and put them across the cap
terminals. Again it should quickly glow then fade out.
"Craig" <craig@nospam.com> wrote in message
newsan.2004.01.02.08.41.02.732000@nospam.com...

I have a 67uf 220V washing machine capacitor that I would like to see if
it works. How can I test it without a capacitance meter?

Thanks.

 

[Phil Allison]

"Craig" <craig@nospam.com>

I have a 67uf 220V washing machine capacitor that I would like to see if
it works. How can I test it without a capacitance meter?

** A good cap will charge - hold that charge, then let it loose with a
bang.

Try charging the cap with a 600 volt 1 amp diode and 100 ohm 5 watt
resistor in series off the AC - be careful and have a safety switch on the
circuit !!!!

Leave it for a few minutes then short the terminals with a clip lead -
should give a nice loud bang and spark.




........... Phil

 

[David]

On Fri, 02 Jan 2004 22:23:15 +1100, Phil Allison wrote:

"Craig" <craig@nospam.com


I have a 67uf 220V washing machine capacitor that I would like to see if
it works. How can I test it without a capacitance meter?


** A good cap will charge - hold that charge, then let it loose with a
bang.

Good caps will NOT let loose any charge with a bang. If the cap lets
the charge loose with a bang the cap is stuffed and probably has an
internal short. A good cap should hold a charge for hours.

Try charging the cap with a 600 volt 1 amp diode and 100 ohm 5 watt
resistor in series off the AC - be careful and have a safety switch on the
circuit !!!!

Extremely dangerous thing to recommend Phil. If the cap is shorted the
diode and resistor will smoke. The cap will potentially have 340V DC
(1.4 x 240VAC) on it, which is pretty lethal. A safety switch (I assume
you mean an RCD device) will not protect you against potential
electrocution if you touch both terminals of the cap.

Leave it for a few minutes then short the terminals with a clip lead -
should give a nice loud bang and spark.

This could destory the capacitor, and cause molten metal to fly from the
arc you create. The current in shorting a large capacitor charged to 340V
DC is only limited by its internal resistance and that of the clip lead,
and could be 100 amps or more. This could also melt the internal
connection of the cap if it was not designed for high current discharges.

If you really want to try this, PLEASE WEAR SAFETY GLASSES to prevent bits
of molten metal and exploding capacitor getting in your eyes.


A much safer way of doing this, if you have access to multimeter, would be
to charge the capacitor from a 9 Volt or 12 Volt battery, with a series
current limiting resistor (or from a current limited power supply if you
have one), and let the cap charge to the battery voltage. Check the
leakage by measuring the current into the cap. It should be less than a mA
or so after the cap has charged.

You could then get an estimate of the capacitance by discharging the cap
into a know resistance. The cap will discharge to approx 37% of its inital
voltage in one time constant, which is the product of R and C. If you
discharged it with a 100K resistor, the voltage should be 37% of the
starting voltage after approx 6.7 seconds. You may need to take into
account the resistance of the voltmeter. By measuring how long it takes to
discharge you can work out its capacitance.

David

 

[Phil Allison]

"David" <no_way@hotmail.com> wrote in message
newsan.2004.01.02.13.56.15.718000@hotmail.com...

On Fri, 02 Jan 2004 22:23:15 +1100, Phil Allison wrote:

"Craig" <craig@nospam.com


I have a 67uf 220V washing machine capacitor that I would like to see
if
it works. How can I test it without a capacitance meter?


** A good cap will charge - hold that charge, then let it loose with a
bang.

Good caps will NOT let loose any charge with a bang.

** Try reading the whole post before going off half cocked - arsehole.

Try charging the cap with a 600 volt 1 amp diode and 100 ohm 5 watt
resistor in series off the AC - be careful and have a safety switch on
the
circuit !!!!


Extremely dangerous thing to recommend Phil.

** Bullshit - it's done all the time with complete safety.

If the cap is shorted the diode and resistor will smoke.

** The 5w resistor will just internally fuse with 300 watts dissipation.

The cap will potentially have 340V DC
(1.4 x 240VAC) on it, which is pretty lethal.

** I can see you have never worked on any valve equipment or off line
SMPS.

A safety switch (I assume
you mean an RCD device) will not protect you against potential
electrocution if you touch both terminals of the cap.

** Nor if a meteorite hits you.

Leave it for a few minutes then short the terminals with a clip lead -
should give a nice loud bang and spark.

This could destory the capacitor, and cause molten metal to fly from the
arc you create.

** What utter bullshit !!!!!!!!!!!!!!



The current in shorting a large capacitor charged to 340V

DC is only limited by its internal resistance and that of the clip lead,
and could be 100 amps or more.

** It will discharge in a millisecond or two.


This could also melt the internal

connection of the cap if it was not designed for high current discharges.

** So you have never seen a camera flash gun or high powered strobe
????????????????

Camera flashes use electro caps of several hundred uF and discharge
them in 1 mS.

Strobes use caps like the one the OP's and charge and discharge them 10
times per second.

If you really want to try this, PLEASE WEAR SAFETY GLASSES to prevent bits
of molten metal and exploding capacitor getting in your eyes.

** What utter rot !!!!!!

The stored energy is only 3.5 joules !!!!!!!!!


Snip rest of fraidy cat drivel - which will not find a defective
cap.



............ Phil

 

[David]

On Sat, 03 Jan 2004 13:02:33 +1100, Phil Allison wrote:

Try charging the cap with a 600 volt 1 amp diode and 100 ohm 5 watt
resistor in series off the AC - be careful and have a safety switch on
the
circuit !!!!


Extremely dangerous thing to recommend Phil.


** Bullshit - it's done all the time with complete safety.

Recommending someone with possibly limited experience connect things
directly to the mains is very dangerous and irresposible thing to do.

If the cap is shorted the diode and resistor will smoke.


** The 5w resistor will just internally fuse with 300 watts dissipation.

Depends on the resistor. If the resistor is not a specially
designed fuseable resistor, it may not fuse without a lot of arcing etc.
There is a big difference between a fuse and a resistor.

The cap will potentially have 340V DC
(1.4 x 240VAC) on it, which is pretty lethal.


** I can see you have never worked on any valve equipment or off line
SMPS.

** I can see you have never had a capacitor blow up in your face.

A safety switch (I assume
you mean an RCD device) will not protect you against potential
electrocution if you touch both terminals of the cap.


** Nor if a meteorite hits you.

Over 30 people a year on average are fatally electrocuted in Australia.
Can you tell me how many have been fatally hit by a meteorite please Phil?

Leave it for a few minutes then short the terminals with a clip lead -
should give a nice loud bang and spark.

Can you tell me how this provides information that the capacitor is the
correct value. Can you tell me how to differentiate between a 10uF and
67uF bang please Phil?

This could also melt the internal
connection of the cap if it was not designed for high current discharges.


** So you have never seen a camera flash gun or high powered strobe
????????????????

Camera flashes use electro caps of several hundred uF and discharge
them in 1 mS.

Strobes use caps like the one the OP's and charge and discharge them 10
times per second.

** Of course I have seen a camera flash gun and strobe lights. I also
know that photo flash capacitors are specially designed to cope with
very rapid high discharge current. They are normally self healing
type.

A bit different to a motor starting capacitor. In fact some motor start
capacitor manufacturers recommend fitting a bleed resistor to the start
capacitor to avoid damaging the run capacitor by excess current discharge.



BTW, fortuntely for you Phil, the Quadrantids meteor shower due 4/5th Jan
will be in the Northern Hemisphere, you should be safe from those.
Watch out for the alpha-Centaurids meteor shower, which begins 28th
Jan and continues into Feb.

David

 

[Phil Allison]

"David" <no_way@hotmail.com

Phil Allison wrote:

Try charging the cap with a 600 volt 1 amp diode and 100 ohm 5 watt
resistor in series off the AC - be careful and have a safety switch
on
the circuit !!!!


Extremely dangerous thing to recommend Phil.


** Bullshit - it's done all the time with complete safety.


Recommending someone with possibly limited experience connect things
directly to the mains is very dangerous and irresposible thing to do.

** More bullshit from a stinking liar. I gave a clear warning of the
need to use a safety switch and use care.

Where were you when folk here were giving instructions to a novice on how
to fix his microwave oven ????

I got roundly abused for saying that was irresponsible.

If the cap is shorted the diode and resistor will smoke.


** The 5w resistor will just internally fuse with 300 watts
dissipation.


Depends on the resistor.

** 5 w resistors are wire wound - they fuse when severely overloaded.

The cap will potentially have 340V DC
(1.4 x 240VAC) on it, which is pretty lethal.


** I can see you have never worked on any valve equipment or off line
SMPS.


I can see you have never had a capacitor blow up in your face.

** I can see you are a fucking bullshit artist.

A safety switch (I assume
you mean an RCD device) will not protect you against potential
electrocution if you touch both terminals of the cap.


** Nor if a meteorite hits you.


Over 30 people a year on average are fatally electrocuted in Australia.

** How many of them were killed by poly caps ????

Leave it for a few minutes then short the terminals with a clip
lead -
should give a nice loud bang and spark.



Can you tell me how this provides information that the capacitor is the
correct value.

** The cap value is most unlikely to have changed.

Other failures are far more likely - they would be revealed by my
suggested test.

** Of course I have seen a camera flash gun and strobe lights. I also
know that photo flash capacitors are specially designed to cope with
very rapid high discharge current.

** You do not know any such thing.

They are normally self healing type.

** Electros are not self healing.

A bit different to a motor starting capacitor.

** We do not know exactly what the cap is - I assumed a polypropylene
as that is what you commonly see in washing machines. Such caps are self
healing and are used in high power (stage) strobes which I have serviced.

Typical failures modes are going open or developing a high internal
resistance.





........... Phil

 

[Bill Bailley]

"Phil Allison" <philallison@optusnet.com.au> wrote in message
news:3ff72e65$0$18750$afc38c87@news.optusnet.com.au...

"David" <no_way@hotmail.com

Phil Allison wrote:



Try charging the cap with a 600 volt 1 amp diode and 100 ohm 5
watt
resistor in series off the AC - be careful and have a safety
switch
on
the circuit !!!!


Extremely dangerous thing to recommend Phil.


** Bullshit - it's done all the time with complete safety.


Recommending someone with possibly limited experience connect things
directly to the mains is very dangerous and irresposible thing to do.

How are you with crocodiles and babies Phil ???

 

[Rod Speed]

"Bill Bailley" <JustMe@Home> wrote in message news:3ff775d1$0$18390$afc38c87@news.optusnet.com.au...

"Phil Allison" <philallison@optusnet.com.au> wrote in message
news:3ff72e65$0$18750$afc38c87@news.optusnet.com.au...

"David" <no_way@hotmail.com

Phil Allison wrote:



Try charging the cap with a 600 volt 1 amp diode and 100 ohm 5
watt
resistor in series off the AC - be careful and have a safety
switch
on
the circuit !!!!


Extremely dangerous thing to recommend Phil.


** Bullshit - it's done all the time with complete safety.


Recommending someone with possibly limited experience connect things
directly to the mains is very dangerous and irresposible thing to do.



How are you with crocodiles and babies Phil ???

All they're good for is croc food.

 

[Arpit]

On Sun, 04 Jan 2004 01:01:35 +1100, David <no_way@hotmail.com> wrote:

On Sat, 03 Jan 2004 13:02:33 +1100, Phil Allison wrote:



Try charging the cap with a 600 volt 1 amp diode and 100 ohm 5 watt
resistor in series off the AC - be careful and have a safety switch on
the
circuit !!!!


Extremely dangerous thing to recommend Phil.


** Bullshit - it's done all the time with complete safety.


Recommending someone with possibly limited experience connect things
directly to the mains is very dangerous and irresposible thing to do.



If the cap is shorted the diode and resistor will smoke.


** The 5w resistor will just internally fuse with 300 watts dissipation.


Depends on the resistor. If the resistor is not a specially
designed fuseable resistor, it may not fuse without a lot of arcing etc.
There is a big difference between a fuse and a resistor.

we are talking 60 times the rated dissipation here. diode will go
quickly in the event of arcing anyway

The cap will potentially have 340V DC
(1.4 x 240VAC) on it, which is pretty lethal.


** I can see you have never worked on any valve equipment or off line
SMPS.



** I can see you have never had a capacitor blow up in your face.

i have,twice, hurts a lot when the top hits your face, but believe me,

no caps are gonna be exploding in phils setup, unless perhaps the
resistor and diode are both short.

A safety switch (I assume
you mean an RCD device) will not protect you against potential
electrocution if you touch both terminals of the cap.


** Nor if a meteorite hits you.


Over 30 people a year on average are fatally electrocuted in Australia.
Can you tell me how many have been fatally hit by a meteorite please Phil?



Leave it for a few minutes then short the terminals with a clip lead -
should give a nice loud bang and spark.



Can you tell me how this provides information that the capacitor is the
correct value. Can you tell me how to differentiate between a 10uF and
67uF bang please Phil?



This could also melt the internal
connection of the cap if it was not designed for high current discharges.


bah one discharge aint gonna kill it
** So you have never seen a camera flash gun or high powered strobe
????????????????

Camera flashes use electro caps of several hundred uF and discharge
them in 1 mS.

Strobes use caps like the one the OP's and charge and discharge them 10
times per second.


** Of course I have seen a camera flash gun and strobe lights. I also
know that photo flash capacitors are specially designed to cope with
very rapid high discharge current. They are normally self healing
type.

A bit different to a motor starting capacitor. In fact some motor start
capacitor manufacturers recommend fitting a bleed resistor to the start
capacitor to avoid damaging the run capacitor by excess current discharge.



BTW, fortuntely for you Phil, the Quadrantids meteor shower due 4/5th Jan
will be in the Northern Hemisphere, you should be safe from those.
Watch out for the alpha-Centaurids meteor shower, which begins 28th
Jan and continues into Feb.

David

 

[Arpit]

On Sun, 4 Jan 2004 08:04:55 +1100, "Phil Allison"
<philallison@optusnet.com.au> wrote:

"David" <no_way@hotmail.com

Phil Allison wrote:



Try charging the cap with a 600 volt 1 amp diode and 100 ohm 5 watt
resistor in series off the AC - be careful and have a safety switch
on
the circuit !!!!


Extremely dangerous thing to recommend Phil.


** Bullshit - it's done all the time with complete safety.


Recommending someone with possibly limited experience connect things
directly to the mains is very dangerous and irresposible thing to do.


** More bullshit from a stinking liar. I gave a clear warning of the
need to use a safety switch and use care.

Where were you when folk here were giving instructions to a novice on how
to fix his microwave oven ????

I got roundly abused for saying that was irresponsible.




If the cap is shorted the diode and resistor will smoke.


** The 5w resistor will just internally fuse with 300 watts
dissipation.


Depends on the resistor.


** 5 w resistors are wire wound - they fuse when severely overloaded.




The cap will potentially have 340V DC
(1.4 x 240VAC) on it, which is pretty lethal.


** I can see you have never worked on any valve equipment or off line
SMPS.


I can see you have never had a capacitor blow up in your face.


** I can see you are a fucking bullshit artist.



A safety switch (I assume
you mean an RCD device) will not protect you against potential
electrocution if you touch both terminals of the cap.


** Nor if a meteorite hits you.


Over 30 people a year on average are fatally electrocuted in Australia.


** How many of them were killed by poly caps ????



Leave it for a few minutes then short the terminals with a clip
lead -
should give a nice loud bang and spark.



Can you tell me how this provides information that the capacitor is the
correct value.


** The cap value is most unlikely to have changed.

Other failures are far more likely - they would be revealed by my
suggested test.




** Of course I have seen a camera flash gun and strobe lights. I also
know that photo flash capacitors are specially designed to cope with
very rapid high discharge current.


** You do not know any such thing.


They are normally self healing type.


** Electros are not self healing.


A bit different to a motor starting capacitor.


** We do not know exactly what the cap is - I assumed a polypropylene
as that is what you commonly see in washing machines. Such caps are self
healing and are used in high power (stage) strobes which I have serviced.

Typical failures modes are going open or developing a high internal
resistance.

THe motor start caps often look very similar to pulse rated caps....
which may or may not be relevant

.......... Phil

 

[Allan]

"David" <no_way@hotmail.com> wrote in message
newsan.2004.01.03.14.01.34.953000@hotmail.com...

On Sat, 03 Jan 2004 13:02:33 +1100, Phil Allison wrote:



Try charging the cap with a 600 volt 1 amp diode and 100 ohm 5 watt
resistor in series off the AC - be careful and have a safety switch
on
the
circuit !!!!


Extremely dangerous thing to recommend Phil.


** Bullshit - it's done all the time with complete safety.


Recommending someone with possibly limited experience connect things
directly to the mains is very dangerous and irresposible thing to do.



If the cap is shorted the diode and resistor will smoke.


** The 5w resistor will just internally fuse with 300 watts
dissipation.


Depends on the resistor. If the resistor is not a specially
designed fuseable resistor, it may not fuse without a lot of arcing etc.
There is a big difference between a fuse and a resistor.




The cap will potentially have 340V DC
(1.4 x 240VAC) on it, which is pretty lethal.


** I can see you have never worked on any valve equipment or off line
SMPS.



** I can see you have never had a capacitor blow up in your face.


A safety switch (I assume
you mean an RCD device) will not protect you against potential
electrocution if you touch both terminals of the cap.


** Nor if a meteorite hits you.


Over 30 people a year on average are fatally electrocuted in Australia.

If your electrocuted it is FATAL...

And Phil is again right..
so get off his back,.

 

[Rod Speed]

"Allan" <allanaws@hotmail.com> wrote in message news:3ffc03bd$0$1747$5a62ac22@freenews.iinet.net.au...

"David" <no_way@hotmail.com> wrote in message
newsan.2004.01.03.14.01.34.953000@hotmail.com...
On Sat, 03 Jan 2004 13:02:33 +1100, Phil Allison wrote:



Try charging the cap with a 600 volt 1 amp diode and 100 ohm 5 watt
resistor in series off the AC - be careful and have a safety switch
on
the
circuit !!!!


Extremely dangerous thing to recommend Phil.


** Bullshit - it's done all the time with complete safety.


Recommending someone with possibly limited experience connect things
directly to the mains is very dangerous and irresposible thing to do.



If the cap is shorted the diode and resistor will smoke.


** The 5w resistor will just internally fuse with 300 watts
dissipation.


Depends on the resistor. If the resistor is not a specially
designed fuseable resistor, it may not fuse without a lot of arcing etc.
There is a big difference between a fuse and a resistor.




The cap will potentially have 340V DC
(1.4 x 240VAC) on it, which is pretty lethal.


** I can see you have never worked on any valve equipment or off line
SMPS.



** I can see you have never had a capacitor blow up in your face.


A safety switch (I assume
you mean an RCD device) will not protect you against potential
electrocution if you touch both terminals of the cap.


** Nor if a meteorite hits you.


Over 30 people a year on average are fatally electrocuted in Australia.

If your electrocuted it is FATAL...

Not necessarily. Plenty survive.

And Phil is again right..

Nope.

so get off his back,.

Heard the one about your head and a dead bear's arse ?

 

[Bob Parker]

"Rod Speed" <rod_speed@yahoo.com> wrote:

If your electrocuted it is FATAL...

Not necessarily. Plenty survive.

Happy New Year Rod,
This is totally pedantic, but according to the two definitions of
"electrocute" Google found for me, it means "Kill by electric shock".
So by that definition, surviving electrocution would be like
surviving being murdered!

Bob

 

[Phil Allison]

"Bob Parker" <bobp@bluebottle.com> wrote in message
news:lmuovvsfnrmbnrg94bciq5k8jrg9olnu9h@4ax.com...

"Rod Speed" <rod_speed@yahoo.com> wrote:

If your electrocuted it is FATAL...

Not necessarily. Plenty survive.


Happy New Year Rod,

This is totally pedantic, but according to the two definitions of
"electrocute" Google found for me, it means "Kill by electric shock".
So by that definition, surviving electrocution would be like
surviving being murdered!

** The Rodbot has survived electrocution numerous times - someone just
replaces his blown fuse.




........... Phil

 

[Rod Speed]

Bob Parker <bobp@bluebottle.com> wrote in message
news:lmuovvsfnrmbnrg94bciq5k8jrg9olnu9h@4ax.com...

Rod Speed <rod_speed@yahoo.com> wrote

If your electrocuted it is FATAL...

Not necessarily. Plenty survive.

Happy New Year Rod,

Thanks, same to you and that cat from hell too |-)

This is totally pedantic, but according to the two definitions of
"electrocute" Google found for me, it means "Kill by electric shock".

Thats what the Macquarie and Oxford say too.

So by that definition, surviving electrocution
would be like surviving being murdered!

That was just a troll so I could admit that my original was wrong.

The latest incarnation of a fatal virus deliverable in plain text
usenet posts, designed to cause a fatal implosion between the
ears of the pathetic creatures reading my posts looking to nit pick |-)

 

[Mike Harding]

On Fri, 9 Jan 2004 08:18:02 +1100, "Rod Speed" <rod_speed@yahoo.com>
wrote:

That was just a troll so I could admit that my original was wrong.

I have printed this in 36pt type and framed it.

Mike Harding

 

[Bob Parker]

"Rod Speed" <rod_speed@yahoo.com> wrote:

Thanks, same to you and that cat from hell too |-)

The cat's really OK. I've got a new photo at
http://members.ozemail.com.au/~bobpar/PA151581.jpg in which it looks
quite human.
It's that scungy yapping fluffy little mongrel dog next door which
is from hell. Take a look at http://bob.parker.web1000.com/yappy.htm
if you haven't already.

 

[Rod Speed]

Bob Parker <bobp@bluebottle.com> wrote in message
news:goetvv8tihbabiie1rl0bv1fscmu1ckjk2@4ax.com...

Rod Speed <rod_speed@yahoo.com> wrote

Thanks, same to you and that cat from hell too |-)

The cat's really OK. I've got a new photo at
http://members.ozemail.com.au/~bobpar/PA151581.jpg
in which it looks quite human.

Yeah, certainly doesnt have the same 'why dont
you go and fuck yourself' glare the last pic had.

It's that scungy yapping fluffy little mongrel dog
next door which is from hell. Take a look at
http://bob.parker.web1000.com/yappy.htm
if you haven't already.

Yeah, lucijet is the answer.