I just installed a high amp relay like used on air conditioners for my well
pump, part 6564K55 McMaster Carr, rated at 40 amp. The enclosure box is
mounted to the floor joists just below the dining room (big mistake).

About once in 50 starts the relay buzzes. The floor joists make a nice
sounding board. SWMBO is NOT happy. It would be a difficult job at best to
move the control box at this point. I could replace the box, but I have
rigid conduit going to this location both from outside the house and over to
the main panel.

Such a thing as a 0 noise relay??? Probably not. Sound deadening ideas(that
meet electrical code)? other suggestions?

Karl

Karl Townsend wrote:
I just installed a high amp relay like used on air conditioners for my well
pump, part 6564K55 McMaster Carr, rated at 40 amp. The enclosure box is
mounted to the floor joists just below the dining room (big mistake).

About once in 50 starts the relay buzzes. The floor joists make a nice
sounding board. SWMBO is NOT happy. It would be a difficult job at best to
move the control box at this point. I could replace the box, but I have
rigid conduit going to this location both from outside the house and over to
the main panel.

Such a thing as a 0 noise relay??? Probably not. Sound deadening ideas(that
meet electrical code)? other suggestions?

Karl




If the relay box is just screwed to tthe floor joists you might try
placing rubber washers between the joist and the box and between the
screw head, with a washer and the box. that SHOULD isolate the box from
the joists and end the problem. I hope I explained my idea
sufficiently. It would also help if one of the washers extended into
the mounting hole on the box to keep the box isolated from the screw
completely.

Jim

"Jim Chandler" wrote: If the relay box is just screwed to tthe floor joists
you might try
placing rubber washers between the joist and the box and between the screw
head, with a washer and the box. (clip)
^^^^^^^^^^^^^^^^^^
That would fix it. You may run into some difficulty raising the box enough
to fit the necessary rubber washers, because of the conduit that is already
in place. You might be able to just squeeze in a layer of rubber between
the joist and the bottom of the box. It that doesn't fix it, then consider
removing some wood from the side of the joist, so the box doesn't touch it.
Let the conduit support the box, or add some other support (like springs.)

Karl Townsend wrote:
...
Such a thing as a 0 noise relay??? ...

Yeah, an SSR. But it would have to be rated for the max (start) current.

Bob

Yeah, an SSR. But it would have to be rated for the max (start) current.

is there such a thing as an SSR for 40 amp 220 VAC?

Karl

Karl Townsend wrote:
Yeah, an SSR. But it would have to be rated for the max (start) current.

is there such a thing as an SSR for 40 amp 220 VAC?

See: http://en.wikipedia.org/wiki/Thyristor
Also: http://en.wikipedia.org/wiki/Silicon...lled_rectifier

There's a photo of an SCR rated about 100A at 1200V. A pair of those
would probably do the job.

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/

Karl Townsend wrote:
Yeah, an SSR. But it would have to be rated for the max (start) current.

is there such a thing as an SSR for 40 amp 220 VAC?

Sure...

http://search.digikey.com/scripts/Dk...name=CC1081-ND

I'd call Crydom and verify the suitability of the part
for motor starting. I'm sure they can find something
that would work. These parts are used in lots of big
nasty industrial equipment.

http://search.digikey.com/scripts/Dk...name=CC1081-ND

I'd call Crydom and verify the suitability of the part
for motor starting. I'm sure they can find something
that would work. These parts are used in lots of big
nasty industrial equipment.

You sold me. The data sheet shows huge start current ability so motors are
no problem. I'm confused by the data sheet.
http://www.crydom.com//userResources...rydom_dual.pdf

It seems to indicate a dual relay. Pic is of a standard SSR. I need to
switch both legs. So, do i need two units? Or, one?

I see relay coil is for 3-32 volt DC. What is best source for DC power
supply. I need something that should last 20 years.

Karl

Karl Townsend wrote:
http://search.digikey.com/scripts/Dk...name=CC1081-ND

I'd call Crydom and verify the suitability of the part
for motor starting. I'm sure they can find something
that would work. These parts are used in lots of big
nasty industrial equipment.

You sold me. The data sheet shows huge start current ability so motors are
no problem. I'm confused by the data sheet.
http://www.crydom.com//userResources...rydom_dual.pdf

It seems to indicate a dual relay. Pic is of a standard SSR. I need to
switch both legs. So, do i need two units? Or, one?

Datasheet is clear that it's a dual. Digikey
shows the wrong picture.

I see relay coil is for 3-32 volt DC. What is best source for DC power
supply. I need something that should last 20 years.

You can't beat Lambda...

http://search.digikey.com/scripts/Dk...me=285-1228-ND

One small caution. Make sure that you have some
sort of air gap disconnect switch or breaker in
series with the SSR. There's usually enough leakage
through an "OFF" SSR to give you a nice jolt if
the load is disconnected.

On Wed, 13 Aug 2008 14:47:14 -0500, "Karl Townsend"
wrote:


http://search.digikey.com/scripts/Dk...name=CC1081-ND

I'd call Crydom and verify the suitability of the part
for motor starting. I'm sure they can find something
that would work. These parts are used in lots of big
nasty industrial equipment.

You sold me. The data sheet shows huge start current ability so motors are
no problem. I'm confused by the data sheet.
http://www.crydom.com//userResources...rydom_dual.pdf

It seems to indicate a dual relay. Pic is of a standard SSR. I need to
switch both legs. So, do i need two units? Or, one?

I see relay coil is for 3-32 volt DC. What is best source for DC power
supply. I need something that should last 20 years.

A couple things to keep in mind:

-The surge rating is for 16 ms = 1 cycle at 60Hz. Your motor surge
will last much longer.

-SSRs are available with 120/240 VAC control and in higher current
ratings, commonly up to 100A IIRC.

-The usual failure mode for SSRs is to fail on. Some fancy SSRs are
self monitoring - Watlow makes a line for heater control where an on
failure would be dangerous, but they're very expensive. Since you're
switching two legs and it's unlikely both relays would fail
simultaneously, you might be able to come up with a simple monitor.

-With a 1.6 volt drop per leg the relay will be dissipating 120 watts
@ 40A. That's a lot of heat in a small enclosure, not to mention
expensive, if run time is significant.

The modules on these pages are aonther possibility. Crydom has similar
products.
http://www.mouser.com/catalog/635/1672.pdf
http://www.mouser.com/catalog/635/1673.pdf

--
Ned Simmons

On 2008-08-13, Karl Townsend wrote:

http://search.digikey.com/scripts/Dk...name=CC1081-ND

I'd call Crydom and verify the suitability of the part
for motor starting. I'm sure they can find something
that would work. These parts are used in lots of big
nasty industrial equipment.

You sold me. The data sheet shows huge start current ability so motors are
no problem. I'm confused by the data sheet.
http://www.crydom.com//userResources...rydom_dual.pdf

It seems to indicate a dual relay. Pic is of a standard SSR. I need to
switch both legs. So, do i need two units? Or, one?

Looking at the drawing, I see an A1-A2 pair and a B1-B2 pair of
terminals, which suggests two circuits controlled with the single input.
Hmm ... actually two pairs of input terminals too, so to get them to
operate at the same time, just connect them in parallel.

I see relay coil is for 3-32 volt DC. What is best source for DC power
supply. I need something that should last 20 years.

A transformer capable of producing 12V at about 2A, connected
through a bridge rectifier and into a couple of filter capacitors. Add
a surge resistor since you won't really *need* all that current
capability, so it will keep the diodes from being fried by power
surges. Make the bridge rectifier good for 200 V PIV so it is unlikely
to get zapped by a lighting surge and you'll probably get your twenty
years of lifetime out of it.

Or -- for quick and dirty -- *two* 12V "wall warts" the power
supplies which plug directly into the outlet, and plug into whatever is
run by them with a barrel connector. Two -- with some diodes so either
will power the relay (it really doesn't want much current at all), and
have each wall wart also powering a LED through a resistor. Look at the
LEDs every so often, to make sure that both are still lit. If one is
out, replace the wall wart with a spare you keep on hand, and go buy a
new spare from Radio Shack for save one from the next cassette player or
whatever that dies.

If you want something to be *sure* to be replaced, use a pair of
opto-isolators with each monitoring one wall wart, and logic such that
if one of the two fails, it turns on a control signal to another
(smaller) SSR (Solid State Relay), which will start an alarm bell
sounding to remind you to replace the wall wart. And be sure to have a
switch to silence it only long enough to get the wall wart replaced
(perhaps a timer) so you wont' forget and leave it off. :-)

Enjoy,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

On 2008-08-13, Karl Townsend wrote:
Yeah, an SSR. But it would have to be rated for the max (start) current.

is there such a thing as an SSR for 40 amp 220 VAC?


Easily available, it is a standard size

Karl Townsend wrote:
Yeah, an SSR. But it would have to be rated for the max (start) current.


is there such a thing as an SSR for 40 amp 220 VAC?

Karl


Yes, sure, look in Digi-Key. I got a 50 A 480 V one from them,
dual pole, too.

Jon

"Karl Townsend" wrote in message
anews.com...
I just installed a high amp relay like used on air conditioners for
my well
pump, part 6564K55 McMaster Carr, rated at 40 amp. The enclosure box
is
mounted to the floor joists just below the dining room (big
mistake).

About once in 50 starts the relay buzzes. The floor joists make a
nice
sounding board. SWMBO is NOT happy. It would be a difficult job at
best to
move the control box at this point. I could replace the box, but I
have
rigid conduit going to this location both from outside the house and
over to
the main panel.

Such a thing as a 0 noise relay??? Probably not. Sound deadening
ideas(that
meet electrical code)? other suggestions?

Karl



Rectify the voltage to the coil, use a decent size of smoothing
capactor, and it should be nice and quiet - you'll need to put a
voltage dropping resistor in series to limit the current to the
original value.

AWEM

Andrew Mawson wrote:
"Karl Townsend" wrote in message
anews.com...

I just installed a high amp relay like used on air conditioners for

my well

pump, part 6564K55 McMaster Carr, rated at 40 amp. The enclosure box

is

mounted to the floor joists just below the dining room (big

mistake).

About once in 50 starts the relay buzzes. The floor joists make a

nice

sounding board. SWMBO is NOT happy. It would be a difficult job at

best to

move the control box at this point. I could replace the box, but I

have

rigid conduit going to this location both from outside the house and

over to

the main panel.

Such a thing as a 0 noise relay??? Probably not. Sound deadening

ideas(that

meet electrical code)? other suggestions?

Karl




Rectify the voltage to the coil, use a decent size of smoothing
capactor, and it should be nice and quiet - you'll need to put a
voltage dropping resistor in series to limit the current to the
original value.

AWEM



You beat me to it! I was gonna suggest a bridge rectifier, cap and
dropping resistor too.

However, upon rereading the OP, he states that the relay only buzzes
"about once in 50 starts".

That says to me there's something not right with that relay, likely
mechanical sloppyness, and if he recently purchased it, perhaps he might
be able to swap it in for a warranty replacement that never buzzes?

Jeff

--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
The speed of light is 1.8*10^12 furlongs per fortnight.

Rectify the voltage to the coil, use a decent size of smoothing
capactor, and it should be nice and quiet - you'll need to put a
voltage dropping resistor in series to limit the current to the
original value.
....
You beat me to it! I was gonna suggest a bridge rectifier, cap and
dropping resistor too.

I originally dismissed this suggestion. Remember, I want 20+ year
reliability. Sounded a bit cobbled together to me. Will this really work
well?



That says to me there's something not right with that relay, likely
mechanical sloppyness, and if he recently purchased it, perhaps he might
be able to swap it in for a warranty replacement that never buzzes?

Its McMasterCarr. They are great on warranty. Is replacing more than a long
shot? More likely, I should go to a different brand; another will do same
thing.

Karl

"Karl Townsend" wrote in message
anews.com...

Rectify the voltage to the coil, use a decent size of smoothing
capactor, and it should be nice and quiet - you'll need to put a
voltage dropping resistor in series to limit the current to the
original value.
...
You beat me to it! I was gonna suggest a bridge rectifier, cap and
dropping resistor too.

I originally dismissed this suggestion. Remember, I want 20+ year
reliability. Sounded a bit cobbled together to me. Will this really
work
well?


Karl



It'll only be cobbled together if that's the way you execute it! It's
a good technical solution - use quality components and well engineered
mounting and it'll be reliable

AWEM

On Wed, 13 Aug 2008 11:59:55 -0500, "Karl Townsend"
wrote:

I just installed a high amp relay like used on air conditioners for my well
pump, part 6564K55 McMaster Carr, rated at 40 amp. The enclosure box is
mounted to the floor joists just below the dining room (big mistake).

About once in 50 starts the relay buzzes. The floor joists make a nice
sounding board. SWMBO is NOT happy. It would be a difficult job at best to
move the control box at this point. I could replace the box, but I have
rigid conduit going to this location both from outside the house and over to
the main panel.

Such a thing as a 0 noise relay??? Probably not. Sound deadening ideas(that
meet electrical code)? other suggestions?

Karl


Bosch makes nice 40 amp relays for automotive use, that are totally
enclosed cubes. They would be prefect except it's dc.

This isnt what I have used in the past but will work.

Here are some ac solid state units.

http://www.crouzet-usa.com/catalog/_ssr.shtml
Daveb

On Wed, 13 Aug 2008 18:54:18 GMT, the renowned (DaveB)
wrote:

On Wed, 13 Aug 2008 11:59:55 -0500, "Karl Townsend"
wrote:

I just installed a high amp relay like used on air conditioners for my well
pump, part 6564K55 McMaster Carr, rated at 40 amp. The enclosure box is
mounted to the floor joists just below the dining room (big mistake).

About once in 50 starts the relay buzzes. The floor joists make a nice
sounding board. SWMBO is NOT happy. It would be a difficult job at best to
move the control box at this point. I could replace the box, but I have
rigid conduit going to this location both from outside the house and over to
the main panel.

Such a thing as a 0 noise relay??? Probably not. Sound deadening ideas(that
meet electrical code)? other suggestions?

Karl


Bosch makes nice 40 amp relays for automotive use, that are totally
enclosed cubes. They would be prefect except it's dc.

12V-rated automotive relays should not be used on the mains. They
don't generally have high enough breakdown voltages guaranteed to get
UL/CSA approvals, for one thing.

If it doesn't start too often you could look at the Potter and
Brumfield (or Siemens or Schrack or Tyco or whoever owns them these
days) T92.

http://www.pandbrelays.com/schrack/pdf/T92.pdf

Check the ratings, obviously, before buying. They're not expensive-
maybe $12-$15. each in singles.


This isnt what I have used in the past but will work.

Here are some ac solid state units.

http://www.crouzet-usa.com/catalog/_ssr.shtml
Daveb


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

On 2008-08-13, Karl Townsend wrote:
I just installed a high amp relay like used on air conditioners for my well
pump, part 6564K55 McMaster Carr, rated at 40 amp. The enclosure box is
mounted to the floor joists just below the dining room (big mistake).

About once in 50 starts the relay buzzes. The floor joists make a nice
sounding board. SWMBO is NOT happy. It would be a difficult job at best to
move the control box at this point. I could replace the box, but I have
rigid conduit going to this location both from outside the house and over to
the main panel.

Such a thing as a 0 noise relay??? Probably not. Sound deadening ideas(that
meet electrical code)? other suggestions?

Can you use an appropriately rated solid state relay?

i

"Karl Townsend" wrote:
I just installed a high amp relay like used on air conditioners for my
well pump, part 6564K55 McMaster Carr, rated at 40 amp. The enclosure box
is mounted to the floor joists just below the dining room (big mistake).

About once in 50 starts the relay buzzes. The floor joists make a nice
sounding board. SWMBO is NOT happy. It would be a difficult job at best
to move the control box at this point. I could replace the box, but I
have rigid conduit going to this location both from outside the house and
over to the main panel.

Such a thing as a 0 noise relay??? Probably not. Sound deadening
ideas(that meet electrical code)? other suggestions?

Karl

If you try to reduce the sound (instead of switching to a SSR), I would
suggest trying to increase the mass of the box which is holding the relay
in addition to trying to isolate it from joists. The heavier it is, the
less it will vibrate which translates to less sound radiated. If you can
for example mount it to a nice heavy piece of steel, and then isolate that
with some rubber mounts from the joists, it should help reduce the level of
noise produced.

--
Curt Welch http://CurtWelch.Com/
http://NewsReader.Com/

The "once in 50 starts" says you have a bad relay or some sort of low
voltage in the driver circuit. I'd be looking at that. Hook up the
meter, wait for it to buzz, see what voltage is across the coil.

Karl Townsend wrote:
I just installed a high amp relay like used on air conditioners for my well
pump, part 6564K55 McMaster Carr, rated at 40 amp. The enclosure box is
mounted to the floor joists just below the dining room (big mistake).

About once in 50 starts the relay buzzes. The floor joists make a nice
sounding board. SWMBO is NOT happy. It would be a difficult job at best to
move the control box at this point. I could replace the box, but I have
rigid conduit going to this location both from outside the house and over to
the main panel.

Such a thing as a 0 noise relay??? Probably not. Sound deadening ideas(that
meet electrical code)? other suggestions?

Karl

Karl Townsend wrote:
I just installed a high amp relay like used on air conditioners for my well
pump, part 6564K55 McMaster Carr, rated at 40 amp. The enclosure box is
mounted to the floor joists just below the dining room (big mistake).

About once in 50 starts the relay buzzes. The floor joists make a nice
sounding board. SWMBO is NOT happy. It would be a difficult job at best to
move the control box at this point. I could replace the box, but I have
rigid conduit going to this location both from outside the house and over to
the main panel.

Such a thing as a 0 noise relay??? Probably not. Sound deadening ideas(that
meet electrical code)? other suggestions?

Karl



Pull the relay box loose and suspend it with a rubber strap.
Pull it loose and use some silicone caulk around each screw to stop the
transfer.

Convince SWMBO that this is a safety feature so you can monitor the pump!
Buy SWMBO a pair of ear plugs!
Replace SWMBO!

--
Steve W.
Near Cooperstown, New York

Ease rubber sheet or washers under the box. Make a fiberglass enclosure
and those will help deaden the sound.

Martin

Martin H. Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
TSRA, Endowed; NRA LOH & Patron Member, Golden Eagle, Patriot's Medal.
NRA Second Amendment Task Force Charter Founder
IHMSA and NRA Metallic Silhouette maker & member.
http://lufkinced.com/


Karl Townsend wrote:
I just installed a high amp relay like used on air conditioners for my well
pump, part 6564K55 McMaster Carr, rated at 40 amp. The enclosure box is
mounted to the floor joists just below the dining room (big mistake).

About once in 50 starts the relay buzzes. The floor joists make a nice
sounding board. SWMBO is NOT happy. It would be a difficult job at best to
move the control box at this point. I could replace the box, but I have
rigid conduit going to this location both from outside the house and over to
the main panel.

Such a thing as a 0 noise relay??? Probably not. Sound deadening ideas(that
meet electrical code)? other suggestions?

Karl




----== Posted via Pronews.Com - Unlimited-Unrestricted-Secure Usenet News==----
http://www.pronews.com The #1 Newsgroup Service in the World! 100,000 Newsgroups
---= - Total Privacy via Encryption =---

On 2008-08-13, Karl Townsend wrote:
I just installed a high amp relay like used on air conditioners for my well
pump, part 6564K55 McMaster Carr, rated at 40 amp. The enclosure box is
mounted to the floor joists just below the dining room (big mistake).

About once in 50 starts the relay buzzes. The floor joists make a nice
sounding board. SWMBO is NOT happy. It would be a difficult job at best to
move the control box at this point. I could replace the box, but I have
rigid conduit going to this location both from outside the house and over to
the main panel.

I suspect that the buzz comes from a small bit of dirt or grain
keeping the solenoid from closing fully. If you can keep it fully
clean, it should not buzz -- but that may be difficult.

Such a thing as a 0 noise relay??? Probably not. Sound deadening ideas(that
meet electrical code)? other suggestions?

Look into a SSR (Solid State Relay). Opto isolater input,
something like 3V to 32V DC to turn it on, anything less and it turns
off.

The ones which I use are 20A 240VAC ones, but I'll bet that you
can find 40A or 50A ones. You'll want to mount it to the metal box with
a heat-sink goop to keep it cool -- especially if you are using it near
its rating.

Good Luck,
DoN.

--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

others have suggested the SSR approach - there is another approach -
energize the relay with DC instead of AC - presuming it's a 24 VDC relay (or
is it a 220V coil?) just rectify, and add a filter cap


"Karl Townsend" wrote in message
anews.com...
I just installed a high amp relay like used on air conditioners for my well
pump, part 6564K55 McMaster Carr, rated at 40 amp. The enclosure box is
mounted to the floor joists just below the dining room (big mistake).

About once in 50 starts the relay buzzes. The floor joists make a nice
sounding board. SWMBO is NOT happy. It would be a difficult job at best to
move the control box at this point. I could replace the box, but I have
rigid conduit going to this location both from outside the house and over
to the main panel.

Such a thing as a 0 noise relay??? Probably not. Sound deadening
ideas(that meet electrical code)? other suggestions?

Karl




** Posted from http://www.teranews.com **

others have suggested the SSR approach - there is another approach -
energize the relay with DC instead of AC - presuming it's a 24 VDC relay
(or is it a 220V coil?) just rectify, and add a filter cap

Ned convinced me that SSR is not that good for my application. The coil on
this one is 120 VAC. McMaster sells the same relay with 24 volt DC coil.
Will a DC coil not buzz? I'll switch it right out if this is true.

Karl

On Thu, 14 Aug 2008 05:20:48 -0500, "Karl Townsend"
wrote:


others have suggested the SSR approach - there is another approach -
energize the relay with DC instead of AC - presuming it's a 24 VDC relay
(or is it a 220V coil?) just rectify, and add a filter cap

Ned convinced me that SSR is not that good for my application. The coil on
this one is 120 VAC. McMaster sells the same relay with 24 volt DC coil.
Will a DC coil not buzz? I'll switch it right out if this is true.

Karl

It shouldn't buzz, but you'll still get the clank when in operates, of
course. But I don't see 24VDC, only 24VAC, which will be no better.

DC coil contactors are also more efficient so the coil will run
cooler.


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

you don't need to change coil voltages. Others have provided good info.
here is some more background

the buzz is because your AC current goes through zero 120 times per second,
and so if the actuator is not fully retracted, the spring will lift it a
bit - it is exactly the design of a buzzer. An AC relay coil has an extra
small copper winding to help this but the buzz is not fully eliminated, and
as you have discovered, it can be pronounced. Going to DC eliminates the
passage through zero, but only if you add a filter capacitor also - if you
use a 120V coil, pretty much any motor start or run capacitor will do the
trick (I'm picking parts you may have lying around). If you are worried
about current limiting, add a series light bulb whose current is near the
coil current (light bulbs, conveniently, are kinda sorta constant current
devices over their useful operating range) - 100 watts per amp aproximately

"Karl Townsend" wrote in message
anews.com...

others have suggested the SSR approach - there is another approach -
energize the relay with DC instead of AC - presuming it's a 24 VDC relay
(or is it a 220V coil?) just rectify, and add a filter cap

Ned convinced me that SSR is not that good for my application. The coil
on this one is 120 VAC. McMaster sells the same relay with 24 volt DC
coil. Will a DC coil not buzz? I'll switch it right out if this is true.

Karl




** Posted from http://www.teranews.com **

"Karl Townsend" wrote in message
anews.com...
I just installed a high amp relay like used on air conditioners for my well
pump, part 6564K55 McMaster Carr, rated at 40 amp. The enclosure box is
mounted to the floor joists just below the dining room (big mistake).

About once in 50 starts the relay buzzes. The floor joists make a nice
sounding board. SWMBO is NOT happy. It would be a difficult job at best to
move the control box at this point. I could replace the box, but I have
rigid conduit going to this location both from outside the house and over
to the main panel.

Such a thing as a 0 noise relay??? Probably not. Sound deadening
ideas(that meet electrical code)? other suggestions?

Karl



mercury switch?

In article s.com,
"Karl Townsend" wrote:

I just installed a high amp relay like used on air conditioners for my well
pump, part 6564K55 McMaster Carr, rated at 40 amp. The enclosure box is
mounted to the floor joists just below the dining room (big mistake).

About once in 50 starts the relay buzzes. The floor joists make a nice
sounding board. SWMBO is NOT happy. It would be a difficult job at best to
move the control box at this point. I could replace the box, but I have
rigid conduit going to this location both from outside the house and over to
the main panel.

Such a thing as a 0 noise relay??? Probably not. Sound deadening ideas(that
meet electrical code)? other suggestions?

A brand new good quality AC contactor should not buzz. I would figure
out why it's buzzing first.

The classic alternate approach if one cannot change the relay is to
interpose a standard rectifier diode bridge, so the relay coil is driven
with DC. Put a varistor or snubber diode across the relay coil, so
spikes generated by the relay coil don't destroy the rectifier bridge.

The other thing to check is that the coil doesn't draw too much current
when fed DC (versus the normal AC). Some AC relays depend on the
inductance of the relay coil to limit current, and this dodge will not
work on DC, so a current-limiting series resistor may also be needed.

Joe Gwinn

Joseph Gwinn fired this volley in news:joegwinn-
:


A brand new good quality AC contactor should not buzz. I would figure
out why it's buzzing first.


The most common cause is some junk caught up in the plunger area, causing
the pole piece not to seat fully when energized.

It only takes a little... Even a dead bug.

LLoyd

Karl Townsend wrote:
I just installed a high amp relay like used on air conditioners for my well
pump, part 6564K55 McMaster Carr, rated at 40 amp. The enclosure box is
mounted to the floor joists just below the dining room (big mistake).

About once in 50 starts the relay buzzes. The floor joists make a nice
sounding board. SWMBO is NOT happy. It would be a difficult job at best to
move the control box at this point. I could replace the box, but I have
rigid conduit going to this location both from outside the house and over to
the main panel.

Such a thing as a 0 noise relay??? Probably not. Sound deadening ideas(that
meet electrical code)? other suggestions?
Solid state relay! Totally noise free. The mechanical relay on
my air compressor used to clang and make me jump, so I put in an
SSR. The first one was too small, and fried. Then I got a 480
V 50 A unit, and it has been handling severe air compressor
service for nearly 10 years, now. (You'll need some kind of
control transformer and rectifier or something to drive the
input signal.

Jon

"Jon Elson" wrote in message
...
Karl Townsend wrote:
I just installed a high amp relay like used on air conditioners for my
well pump, part 6564K55 McMaster Carr, rated at 40 amp. The enclosure box
is mounted to the floor joists just below the dining room (big mistake).

About once in 50 starts the relay buzzes. The floor joists make a nice
sounding board. SWMBO is NOT happy. It would be a difficult job at best
to move the control box at this point. I could replace the box, but I
have rigid conduit going to this location both from outside the house and
over to the main panel.

Such a thing as a 0 noise relay??? Probably not. Sound deadening
ideas(that meet electrical code)? other suggestions?
Solid state relay! Totally noise free. The mechanical relay on my air
compressor used to clang and make me jump, so I put in an SSR. The first
one was too small, and fried. Then I got a 480 V 50 A unit, and it has
been handling severe air compressor service for nearly 10 years, now.
(You'll need some kind of control transformer and rectifier or something
to drive the input signal.

Jon

I'm told SCRs fail closed, something to think about...

I just installed a high amp relay like used on air conditioners for my well
pump, part 6564K55 McMaster Carr, rated at 40 amp. The enclosure box is
mounted to the floor joists just below the dining room (big mistake).

About once in 50 starts the relay buzzes. The floor joists make a nice
sounding board. SWMBO is NOT happy. It would be a difficult job at best to
move the control box at this point. I could replace the box, but I have
rigid conduit going to this location both from outside the house and over to
the main panel.

Such a thing as a 0 noise relay??? Probably not. Sound deadening ideas(that
meet electrical code)? other suggestions?

Karl

Check the mounting specs on that relay .. .. some are to be mounted in
a certain orientation, vertical, horizontal, etc. Possibly weakening
the spring which opens the contacts after coil current is off will
eliminate your problem.... coil trying to pull the armature UPHILL
against a sturdy spring can cause chatter. HTH
Ken.