Hi chaps,

i have a relay switching 11 amps @ 230volts, i want to supress the EM noise
from it with one of these but cant work out which one i need.

RS does this range-

http://uk.rs-online.com/web/search/s...ct&R=020923 5

From the pdf documents, there is some help to size the cap and the R values
to the application. From my calcs i recon i need a 20uf 20rR

Help! I'm out of my depth here and RS tech support recommended one of
these-

http://uk.rs-online.com/web/search/s...ct&R=038536 0

but its too expensive as i need 20! And im not sure they have sized it
correctly.

TIA!

Steve

On Nov 8, 4:14*pm, "Mr Sandman" wrote:
Hi chaps,

i have a relay switching 11 amps @ 230volts, i want to supress the EM noise
from it with one of these but cant work out which one i need.

RS does this range-

http://uk.rs-online.com/web/search/s...tml?method=get....

From the pdf documents, there is some help to size the cap and the R values
to the application. *From my calcs i recon i need a 20uf 20rR

Help! *I'm out of my depth here and RS tech support recommended one of
these-

http://uk.rs-online.com/web/search/s...tml?method=get....

but its too expensive as i need 20! *And im not sure they have sized it
correctly.

TIA!

Steve

0.1uF + 100 ohms is the standard values to use. You dont say what the
load is, there's a fair difference between resistive aqnd inductive
loads. If its resistive I'd go with the usual values.

0.22uF + 47 ohms will also work, and may work better if the load's
inductive, but it will also leak more current when the relay's off,
and increase the peak current on closing for the relay contacts by
about 5A. You'd need to spec your relay to cope with this if you want
it to last.

Either suppressor wll leave the switched live permanently live enough
to deliver a serious shock.


NT

Mr Sandman wrote:
Hi chaps,

i have a relay switching 11 amps @ 230volts, i want to supress the EM
noise from it with one of these but cant work out which one i need.

RS does this range-

http://uk.rs-online.com/web/search/s...ct&R=020923 5


From the pdf documents, there is some help to size the cap and the R
values to the application. From my calcs i recon i need a 20uf 20rR


?? I doubt you nee that. More like .1uF...
A bit of inductance would help as well.

try a toroid with a few turns is series with the contacts and .1uF
across them.

On Nov 8, 4:37*pm, Tabby wrote:
On Nov 8, 4:14*pm, "Mr Sandman" wrote:



Hi chaps,

i have a relay switching 11 amps @ 230volts, i want to supress the EM noise
from it with one of these but cant work out which one i need.

RS does this range-

http://wiki.diyfaq.org.uk/index.php?title=Snubber


NT

Tabby, the load is 2.4kw kettle element on some relays and on others this
pump-

http://www.altecweb.com/home.asp?cat=Subcategory41110

I have emailed the company and am waiting for them to get back to me
regarding the power consumption and inrush....

steve


"Tabby" wrote in message
...

On Nov 8, 4:14 pm, "Mr Sandman" wrote:
Hi chaps,

i have a relay switching 11 amps @ 230volts, i want to supress the EM
noise
from it with one of these but cant work out which one i need.

RS does this range-

http://uk.rs-online.com/web/search/s...tml?method=get...

From the pdf documents, there is some help to size the cap and the R
values
to the application. From my calcs i recon i need a 20uf 20rR

Help! I'm out of my depth here and RS tech support recommended one of
these-

http://uk.rs-online.com/web/search/s...tml?method=get...

but its too expensive as i need 20! And im not sure they have sized it
correctly.

TIA!

Steve

0.1uF + 100 ohms is the standard values to use. You dont say what the
load is, there's a fair difference between resistive aqnd inductive
loads. If its resistive I'd go with the usual values.

0.22uF + 47 ohms will also work, and may work better if the load's
inductive, but it will also leak more current when the relay's off,
and increase the peak current on closing for the relay contacts by
about 5A. You'd need to spec your relay to cope with this if you want
it to last.

Either suppressor wll leave the switched live permanently live enough
to deliver a serious shock.


NT

On Nov 8, 6:03*pm, "Mr Sandman" wrote:
Tabby, the load is 2.4kw kettle element on some relays and on others this
pump-

http://www.altecweb.com/home.asp?cat=Subcategory41110

0.1uF 100 ohms should be good for both those.


I have emailed the company and am waiting for them to get back to me
regarding the power consumption and inrush....

steve

no need

I'm NT btw, not Tabby


NT


"Tabby" *wrote in message

...

On Nov 8, 4:14 pm, "Mr Sandman" wrote:



Hi chaps,

i have a relay switching 11 amps @ 230volts, i want to supress the EM
noise
from it with one of these but cant work out which one i need.

RS does this range-

http://uk.rs-online.com/web/search/s...tml?method=get....

From the pdf documents, there is some help to size the cap and the R
values
to the application. *From my calcs i recon i need a 20uf 20rR

Help! *I'm out of my depth here and RS tech support recommended one of
these-

http://uk.rs-online.com/web/search/s...tml?method=get....

but its too expensive as i need 20! *And im not sure they have sized it
correctly.

TIA!

Steve

0.1uF + 100 ohms is the standard values to use. You dont say what the
load is, there's a fair difference between resistive aqnd inductive
loads. If its resistive I'd go with the usual values.

0.22uF + 47 ohms will also work, and may work better if the load's
inductive, but it will also leak more current when the relay's off,
and increase the peak current on closing for the relay contacts by
about 5A. You'd need to spec your relay to cope with this if you want
it to last.

Either suppressor wll leave the switched live permanently live enough
to deliver a serious shock.

NT

Owain wrote:
On Nov 8, 10:34*pm, Tabby *wrote:

I'm NT btw, not Tabby

But your From name is Tabby?

Owain

Yeah, couldnt find any way to correct it in google groups.


NT

Fanks NT!

Steve

"Tabby" wrote in message
...

On Nov 8, 6:03 pm, "Mr Sandman" wrote:
Tabby, the load is 2.4kw kettle element on some relays and on others this
pump-

http://www.altecweb.com/home.asp?cat=Subcategory41110

0.1uF 100 ohms should be good for both those.


I have emailed the company and am waiting for them to get back to me
regarding the power consumption and inrush....

steve

no need

I'm NT btw, not Tabby


NT


"Tabby" wrote in message

...

On Nov 8, 4:14 pm, "Mr Sandman" wrote:



Hi chaps,

i have a relay switching 11 amps @ 230volts, i want to supress the EM
noise
from it with one of these but cant work out which one i need.

RS does this range-

http://uk.rs-online.com/web/search/s...tml?method=get...

From the pdf documents, there is some help to size the cap and the R
values
to the application. From my calcs i recon i need a 20uf 20rR

Help! I'm out of my depth here and RS tech support recommended one of
these-

http://uk.rs-online.com/web/search/s...tml?method=get...

but its too expensive as i need 20! And im not sure they have sized it
correctly.

TIA!

Steve

0.1uF + 100 ohms is the standard values to use. You dont say what the
load is, there's a fair difference between resistive aqnd inductive
loads. If its resistive I'd go with the usual values.

0.22uF + 47 ohms will also work, and may work better if the load's
inductive, but it will also leak more current when the relay's off,
and increase the peak current on closing for the relay contacts by
about 5A. You'd need to spec your relay to cope with this if you want
it to last.

Either suppressor wll leave the switched live permanently live enough
to deliver a serious shock.

NT

On Mon, 8 Nov 2010 15:35:41 -0800 (PST), Tabby wrote:


Yeah, couldnt find any way to correct it in google groups.

According to
http://groups.google.com/support/bin...n&answer=19870

"If you use Gmail with your Google Account, it's not currently possible to
change your Gmail username after you've registered. You can, however, create
another Google Account with a different Gmail username."

"If you don't use Gmail with your Google Account, you can change your account
username to another email address at any time. Your username is the full email
address you used to create your account."

--
Geo