Extending life of well pump relay...??

[sno]

I just replaced my well pump relay due to arcing wearing away the
contacts...

It seems I am replacing the relay about every 1.5 to 2 years...and it
seems to happen always in the middle of winter...it is a bummer to
replace it when the weather is bad...I would like to get maybe 6 more
months out of one....

The pressure tank is fine...I realize that if I get a bigger tank the
pump would cycle less....but do not want to spend the money on a bigger
tank especially when the tank I presently have is good....

I seem to remember something about hooking up a capacitor in some manner
to prevent arcing on relays....does anyone have any ideas or know how to
hook up capacitor...??....and the value that is needed...
or any other tricks...??....the pump is wired to work at 110 volts AC...

thank you for any help....have fun....sno

 

[Ecnerwal]

I just replaced my well pump relay due to arcing wearing away the
contacts...

It seems I am replacing the relay about every 1.5 to 2 years...and it
seems to happen always in the middle of winter...it is a bummer to
replace it when the weather is bad...I would like to get maybe 6 more
months out of one....

The pressure tank is fine...I realize that if I get a bigger tank the
pump would cycle less....but do not want to spend the money on a bigger
tank especially when the tank I presently have is good....

I seem to remember something about hooking up a capacitor in some manner
to prevent arcing on relays....does anyone have any ideas or know how to
hook up capacitor...??....and the value that is needed...
or any other tricks...??....the pump is wired to work at 110 volts AC...

Snubber: for instance (a little ways down the page)
http://www.allaboutcircuits.com/vol_4/chpt_4/2.html

I wonder if you are low-balling the quality of your pump relay, since
the typical square D relay works many years without trouble.

Anyway, to avoid burnt contacts - use a Solid State Relay - no contacts
to burn, no moving parts.

Since the well industry is so far behind everything else electrically,
you probably can't do this in one part.

Use the pressure switch to switch the input to a SSR that is at least
twice (and more is better) the rated amperage of your pump. Use the SSR
to actually control power to the pump. And get another pressure tank
(you can add one, rather than having to throw away a good one and
replace it with a bigger one - and the one you add does not need to be
where the first one is.)

Then again, an SSR may die even faster, if the real problem is that you
need to bond your well casing to your grounds, and put surge arrestors
on the well wiring. Delta LA302 or LA302R (easier to find at reduced
price, but not quite as beefy as the LA302) and perhaps a CA302R for
good measure. Lighting can play havoc with wells.

 

[sno]

Snubber: for instance (a little ways down the page)
http://www.allaboutcircuits.com/vol_4/chpt_4/2.html

I wonder if you are low-balling the quality of your pump relay, since
the typical square D relay works many years without trouble.

Anyway, to avoid burnt contacts - use a Solid State Relay - no contacts
to burn, no moving parts.

Since the well industry is so far behind everything else electrically,
you probably can't do this in one part.

Use the pressure switch to switch the input to a SSR that is at least
twice (and more is better) the rated amperage of your pump. Use the SSR
to actually control power to the pump. And get another pressure tank
(you can add one, rather than having to throw away a good one and
replace it with a bigger one - and the one you add does not need to be
where the first one is.)

Then again, an SSR may die even faster, if the real problem is that you
need to bond your well casing to your grounds, and put surge arrestors
on the well wiring. Delta LA302 or LA302R (easier to find at reduced
price, but not quite as beefy as the LA302) and perhaps a CA302R for
good measure. Lighting can play havoc with wells.

Looks like a snubber is the easiest way to go....will try it....
googling snubber leads me to believe a 100 ohm resistor and 100 or
greater nanofarad capacitor with voltage of about 600 volts or so should
work...

thank you very, very much for the help and information....have fun....sno

 

[[email protected]]

I just replaced my well pump relay due to arcing wearing away the
contacts...

It seems I am replacing the relay about every 1.5 to 2 years...and it
seems to happen always in the middle of winter...it is a bummer to
replace it when the weather is bad...I would like to get maybe 6 more
months out of one....

The pressure tank is fine...I realize that if I get a bigger tank the
pump would cycle less....but do not want to spend the money on a bigger
tank especially when the tank I presently have is good....

I seem to remember something about hooking up a capacitor in some manner
to prevent arcing on relays....does anyone have any ideas or know how to
hook up capacitor...??....and the value that is needed...
or any other tricks...??....the pump is wired to work at 110 volts AC...

thank you for any help....have fun....sno

Have you checked the current draw of the pump against its specs? If
you have a control box, have you checked it out?

Your short relay life is highly unusual in my experience, even the
cheapest contactors seem to last a long time. Although I have seen a
couple of cases of pressure switches failing every few months, caused
by ants. For whatever reason they're drawn to the contacts and
immolate themselves. Fix is to move or seal off the switch.

Wayne

 

[sno]

Have you checked the current draw of the pump against its specs? If
you have a control box, have you checked it out?

Your short relay life is highly unusual in my experience, even the
cheapest contactors seem to last a long time. Although I have seen a
couple of cases of pressure switches failing every few months, caused
by ants. For whatever reason they're drawn to the contacts and
immolate themselves. Fix is to move or seal off the switch.

Wayne

I suspect the short life is due to the fact that I have to keep water
flowing all winter to prevent freezing...is not possible to bury piping
below frost depth....also during winter heat only one room, pipes in
house can freeze...(both have frozen in past)....which leads to all
sorts of problems....<grin>

have fun.....sno

--
Correct Scientific Terminology:
Hypothesis - a guess as to why or how something occurs
Theory - a hypothesis that has been checked by enough experiments
to be generally assumed to be true.
Law - a hypothesis that has been checked by enough experiments
in enough different ways that it is assumed to be truer then a theory.
Note: nothing is proven in science, things are assumed to be true.

 

[[email protected]]

I suspect the short life is due to the fact that I have to keep water
flowing all winter to prevent freezing...is not possible to bury piping
below frost depth....also during winter heat only one room, pipes in
house can freeze...(both have frozen in past)....which leads to all
sorts of problems....<grin>

I still think it's unusual. A common failure mode is pressure tank
fails, then pump fails due to crazy number of cycles. Yet the pressure
switch or relay is still OK, and that includes the ones switching
higher horsepower. Anyway, another cheap and easy fix that might work
for you - 2 relays in parallel.

Wayne

 

[Bob F]

I still think it's unusual. A common failure mode is pressure tank
fails, then pump fails due to crazy number of cycles. Yet the pressure
switch or relay is still OK, and that includes the ones switching
higher horsepower. Anyway, another cheap and easy fix that might work
for you - 2 relays in parallel.

I don't think that really helps. Do to slight differences in opening/closing
times, one relay ends up taking the switching load.

 

[sno]

I still think it's unusual. A common failure mode is pressure tank
fails, then pump fails due to crazy number of cycles. Yet the pressure
switch or relay is still OK, and that includes the ones switching
higher horsepower. Anyway, another cheap and easy fix that might work
for you - 2 relays in parallel.

Wayne

AHHHH....Great idea...!!!...thank you....have fun....sno


--
Correct Scientific Terminology:
Hypothesis - a guess as to why or how something occurs
Theory - a hypothesis that has been checked by enough experiments
to be generally assumed to be true.
Law - a hypothesis that has been checked by enough experiments
in enough different ways that it is assumed to be truer then a theory.
Note: nothing is proven in science, things are assumed to be true.

 

[[email protected]]

I don't think that really helps. Do to slight differences in opening/closing
times, one relay ends up taking the switching load.

Sure, but the object is to have one relay working. Consider it as
having the replacement waiting in the wings.

Wayne

 

[You]

Snubber: for instance (a little ways down the page)
http://www.allaboutcircuits.com/vol_4/chpt_4/2.html

I wonder if you are low-balling the quality of your pump relay, since
the typical square D relay works many years without trouble.

Anyway, to avoid burnt contacts - use a Solid State Relay - no contacts
to burn, no moving parts.

Finally, someone who is thinking of fixes that are 21st Century
Technology... I mean really, all this 20th Century Technology is fine,
but antiquated... A good SSR, with 120, or 240 Vac Control isn't all
that hard to come by... ANY good electrical supply House will have them
Off the Shelf... I mean Really... who uses contactors these days....

 

[[email protected]]

I mean Really... who uses contactors these days....

For residential water wells - pretty much everybody except those with
the constant-pressure variety. The OP's contactor is probably the
usual open-frame type commonly used for up to about 3 hp. They cost
about $8 and tend to last for a decade or more. Pressure switches cost
about $15. Primitive yes, but cheap, effective, and available at the
local hardware store (sometimes at silly prices) in rural areas.

Wayne

 

[sno]

All switches have a life expectancy - typically about 100,000 switch
cycles. You must decide which is causing contact failure. Do you
have a wiring problem? Is your motor too large for the switch contact
ratings? Is some defect in the motor causing switch arcing? Or is it
just switching too many times.

Well, your water pressure should drop by a certain amount before the
pump triggers. To reduce the number of power cycles, that water
pressure variation should be greater.

We once replaced switches with mercury wetted contacts so that
switch life expectancy was longer. Today you can use a solid state
relay.

If the pump motor is too deep, or is the wiring is too undersized
causing too must current on startup - both are examples of defective
wiring or pump that can cause contact failure. Defective wiring means
the pump consumes too much current on startup - and will eventually
cause pump motor failure. Low voltage would also cause this problem.
Then when you use heavier contacts, the symptom is cured but the
problem remains.

Bottom line - nobody can provide a useful answer without critical
numbers that first define the problem. Replacing something only on
wild speculation (ie SSR contacts) may only result in an expensive
pump motor failure later. Only one with electrical knowledge (and the
necessary test equipment) can get numbers. Until you have those
numbers, then nobody can recommend a solution.

Of course, counting the number of power cycles per hour is a first
number you provide for a useful answer.

I ordered the parts today for a snubber....will see if arcing
stops....if it does not then will borrow some test equipment and see if
I can figure out what is going on...

The pump itself is about 10/15 yrs old in that time the only thing that
has gone wrong is some rocks got sucked up somehow and had to replace
impeller....

I had a new switch box installed last year and wire was completely
replaced....so probably not a wiring problem, in addition have not had
relay last in all the time have had the pump....this is first time have
replaced relay since the new wiring....about the same time period as in
the past.....

Have noticed that the contacts only arc on one side...maybe because one
side opens before other...??....one side opens hot wire
the other opens neutral...

Anyway will see how the snubber works....and then go on from there....

Thanks everyone for their thoughts and help....have fun.....sno

 

[sno]

Wire means every part of the cable from breaker box to the pump.
For example, is the connection to the circuit breaker loose? Then a
meter would report a constant lower voltage to the pump. That low
voltage means the pump draws a larger startup current.

If the weakened or defective wiring is in the well, then only a
current measurement might show a result. But that means you know what
a normal startup current is. Not something a digit meter will
measure.

If the pump was working without contact failure for 15 years, then
another reason for failure - wire gauge too thin for that distance and
pump - probably is not a suspect.

The troubling part. Why is that pressure switch good enough for
hundreds of thousands of other pumps just like yours? Why do those
other 100,000 switch contacts no need a snubber? Start by suspecting
the snubber is only 'curing a symptom'. Or is the new switch grossly
undersized for that pump (especially if it is deeper than most)?
Again, an example of why numbers result in more useful replies.

Meanwhile, how often does the pump power cycle in an hour?

It cycles aprox. every 1.5 minutes....when I have three faucets running
(bathroom tub and sink faucets full on) the pump runs continuous....that
works out to 960 cycles per day....28800 per month....during winter
about 3 months...86400 cycles..
which works out to somewhere between 50,000 to 100,000 per year....about
the 100,000 is rated for....so as I suspected, reason for not lasting is
the water running in winter....

If snubber works should greatly extend the life...

thank you for your help....have fun....sno

 

[sno]

Consider changing (widening) power off and power on pressure points
so that the pump does not power cycle frequently. It may also extend
pump life expectancy.

good idea....will try it with the snubber....

That number explains contact failure. A larger amperage switch
(with that snubber) would help. Using multiple switches will not help
(as I think another has explained).

Have been thinking....if snubber does not work....have a friend who
works for a plumber....maybe can get a used hot water non leaking water
tank...and add it to the system as a pressure tank without bladder...a
40 gallon tank would take some time to fill up....and i have the room
for it next to my present hot water tank.....

thanks for your ideas and help.....have fun.....sno

 

[[email protected]]

good idea....will try it with the snubber....


Have been thinking....if snubber does not work....have a friend who
works for a plumber....maybe can get a used hot water non leaking water
tank...and add it to the system as a pressure tank without bladder...a
40 gallon tank would take some time to fill up....and i have the room
for it next to my present hot water tank.....

Used like that a 40 gallon tank wouldn't add much capacity. And
conventional tanks are a pain compared to bladder types.
http://www.nationaldriller.com/Articles/Column/c04c543281b39010VgnVCM100000f932a8c0____
http://www.inspectapedia.com/water/WaterTankMath.htm

80 gallons is a common size for bladder tanks. At 30/50 (cut-in and
cut-out pressure in psi) they hold about 25 gallons of water.

Have you verified proper pre-charge in your existing tank?
http://www.inspectapedia.com/water/Water_Tank_Bladder_Adjust.htm


Wayne

 

[sno]

Used like that a 40 gallon tank wouldn't add much capacity. And
conventional tanks are a pain compared to bladder types.
http://www.nationaldriller.com/Articles/Column/c04c543281b39010VgnVCM100000f932a8c0____
http://www.inspectapedia.com/water/WaterTankMath.htm

80 gallons is a common size for bladder tanks. At 30/50 (cut-in and
cut-out pressure in psi) they hold about 25 gallons of water.

Have you verified proper pre-charge in your existing tank?
http://www.inspectapedia.com/water/Water_Tank_Bladder_Adjust.htm


Wayne

yep....have verified present tank is ok...and at proper pressure...
the 40 gallon tank would be used along with the bladder tank....
even if I had to drain the 40 gallon every two months or so would be a
great help....and during summer could have a valve to cut it out of the
system...maybe would be able to get by draining it right before winter
and right after....I am hoping by adding snubber will solve my problem..
I have the components on order and it will cost less than 10 dollars...
will update how things work....when I get done....<grin>

thanks for info on non bladder tanks....have fun...sno


--
Correct Scientific Terminology:
Hypothesis - a guess as to why or how something occurs
Theory - a hypothesis that has been checked by enough experiments
to be generally assumed to be true.
Law - a hypothesis that has been checked by enough experiments
in enough different ways that it is assumed to be truer then a theory.
Note: nothing is proven in science, things are assumed to be true.

 

[sno]

First off, a look at problem solving;

When things go wrong they seem to do so with a twisted sort of
maleviolent
vengeance. Problem piled on mistake compounded by silliness raised to
catastrophe may sound familiar to many of us.
So how do these things happen? Well, in many cases we do them to
ourselves. It has to do with mind set and reaction. We see a problem
and
react to it.
As an example let's look at a problem that arose just this weekend. I
had
been to Bill's to install a new battery charger for his solar power
system. To
set the scene this system was installed by the previous owner. Bill
bought
the house and the system connected to it. Now, while the previous
owner
knew what he had done he never documented it.
During the installation of a new battery charger I had to disconnect
the
alternator, which had been the battery charger up to this point. To
cut
this long story short, by disconnecting the alternator I had also
unknowingly
disabled the starting circuit for the diesel generator.
That night I got a call to say that the generator would not start.
Well,
okay, this was my fault. I went right then to fix this problem. Yes,
this is
the Problem which is piled on the Mistake.
Right. Problem solved and the generator is running again. The new
battery charger is working great and pumping fifty amps into the
batteries.
At this point there are some who will have noticed that the equation
"Problem piled on mistake compounded by silliness raised to
catastrophe" is
not finished.
Late the next day I get a phone call to say that Bill's twelve volt
fridge has
ceased to function and has defrosted itself. I suggested that the
first thing
to check was that there was power to the socket that the fridge is
plugged
into. Answer is - No, but when the fridge is plugged into another
socket on
the other side it works.
Later that same day I get a phone call. The twelve volt lights in the
lounge room do not work. As you can see the equation is still running.
I go over the possible problems with Bill, check the fuses, check for
power
at the fuse box and so forth. The upshot is that the fuses are ok but
there
is no power to the lighting circuit. You have got to understand. This
is not
right. In fact it is just plain silly. It's the sort of thing that can
reduce a
grown man to a gibbering fool in a very short space of time. What we
are
talking about is "Wandering circuit failure".
Well we now have the full equation. Problem (generator does not start)
piled on mistake (generator starter disconnected) compounded by
silliness
(we will get to this in a moment) raised to catastrophe (fridge full
of food
defrosted).
Evening day three. I get a phone call from Bill. Everything is all
right.
Silliness, it seems that Bill has had guests over for the weekend. At
some
time during the weekend someone turned off the master switch for the
lights
in the lounge room. Which, would you believe it, includes the circuit
for the
fridge.
Now I am not poking fun at Bill. The point I am making is that when
you start looking for solutions to problems, such as lights or other
appliances
failing to work or in fact any other problem, always start with the
simplest
solution. i.e. Turn on the switch. I know it sounds stupid but we all
do it.
A problem comes up and we forget the simple solutions. Maybe it is the
fact
that the growth of technology has led us to be too technical in our
search for
the answers to problems. Like the song says `Slow down, you move too
fast,
you've got to make the morning last.'
Don't jump to conclusions. Walk through the problem from the beginning
to the end. If a light fails to work, check the light first, then the
socket, then
the wire, then the switch. . . etc.
Now if I could just remember this advice I would be a much calmer
person.

Ok, your problem of short lived relay contacts.

It would seem, on quiet reflection, that you are trying to fix a
symptom rather than the cause.

From what you have said, with all the taps turned off, your pump
cycles every 90 seconds.

Possible causes:

1) Leak in water system. In a frost prone are this is a common problem
due to thermal cycling of joints.

2) Flooded pressure tank. This is also a common problem, which is why
many pressure tanks have a recharge port on them.

3) Both of the above.

Explanation; System is water pump and pressure tank. If water system
leaks then the pump will cycle whenever the pressure drops below the
preset low pressure point. In the case of a flooded pressure tank
there is not enough compressed gas to maintain pressure above the
preset low pressure point.

Either or both of these two problems can and will cause excessive
cycling.

You have to go back and read the whole thread....I keep tap running all
winter to prevent freeze up...cannot bury pipes deep enough to keep them
from freezing...I only heat/live in one room in winter so pipes run
through furthest wall can freeze. As figured out everything is ok
except running the water all winter causes to many cycles of
relay...causing replacing of relay (burnt contacts) about every 1.5/2 yrs.

LOL....what you are talking about everyone who works with electricity
for any length of time has discovered....first make sure it is plugged
in....second turn on all switches....<grin>
third remember electricity is really magic...<grin>...and sometimes what
seems like the impossible can happen....

have fun......sno

 

[vaughn]

Used like that a 40 gallon tank wouldn't add much capacity. And
conventional tanks are a pain compared to bladder types.

Perhaps, but that is all I ever had on my last home's system and I got along
just fine. It works best if you own an air compressor. Just at a Schrader
valve somewhere on the tank and blow in the occasional tank full of air.

Vaughn

 

[[email protected]]

Perhaps, but that is all I ever had on my last home's system and I got along
just fine. It works best if you own an air compressor. Just at a Schrader
valve somewhere on the tank and blow in the occasional tank full of air.

Vaughn

Sure, lots of people do well with pressure tanks that size. Usually
the ones using sensible amounts of water. The problem arises when
you're using more, say running multiple outlets at once. Then you get
rapid cycling. Wait, what were we talking about again? ;-) Anyway,
considering the trouble people manage to get into with bladder tanks,
I never mention conventionals except to DIYers. They're still popular
though in some large installations in my area. One I remember was
perhaps 2000 gallons, and had a small auto-start compressor installed.
That kind of thing, and pressure tanks in general, are headed towards
extinction though as constant-pressure pumps become more popular. Some
types of those are already cost-effective, like this one
http://www.deanbennett.com/constant-pressure-centrifugal-pumps.htm
that I used to replace a multi-tank conventional setup. Available in
lower capacities also. For lift apps, these are neat, albeit
expensive. http://www.deanbennett.com/artesian-vfd-drives.htm. Still,
when you consider that they can sometimes be used to eliminate one
pump, a storage tank, pressure tank(s), controls, and motor protection
devices, they're pretty slick.

Wayne

 

[Ecnerwal]

It seems to me that the real problem is your inability to bury the line
leading from the pressure tank to your house deep enough to prevent it
from freezing.

I'm wondering if you might be able to run that water line through a
larger black plastic pipe through which you feed just enough warm air to
prevent the water in the inner pipe from freezing...

Another option is "inside the pipe heat tape". If it freezes up, turn on
the heat, when it thaws enough for water to flow, turn off the heat
until it freezes again. Probably use a lot less power than running the
pump all the time, too. If you have a septic system, also much better
for that than running water all winter. Works better if you insulate the
waterline.

Of course, if you insulate the waterline with sheet polystyrene (XPS,
waterproof, ground contact, usually pink, blue or green rather than
white) far enough sideways, it's just as effective as burying the pipe
deeper, and uses no power. A pipe with a 4 foot wide sheet of insulation
centered over it (right on top of the pipe) that is then buried 1 foot
deep is effectively the same as burying the pipe 3 feet deep.