Those of you who read my report on my grandiose bilge system know that
I ignored the advice of the capacitance switch builder who said they
couldn't cost less than a grand and work. Well, he was right. This is
a great idea but it's not ready for prime time on most boats.

I set the whole thing up in my basement in a tub about the size of my
bilge sump with the hose let uphill to simulate the run that will go
in the boat.

Other solid state, electronic float switches have a high "On" trigger
point and a lower "Off" trigger. The See Water is instant on when
water touches the probe. Even a splashed drop seems to set it off.
There is no ON time delay at all. The instant the water drops below
the probe, an 8 - 10 second time delay starts. This is to draw the
water down low enough that backflow through the hoses won't set up an
endless cycle that drains the batteries. Unfortunately, the time delay
is totally inadequate for the length of hose run that would be found
on most sailboats.

I also noticed that the switch twice did not shut off at all and this
is while brand new and clean in a test set up. Once down in the bilge
with some stuff floating around, who knows? Fortunately, West Marine
has a great return policy and took both switches back even though I
had to hack the wires short to remove them.

I've now done what I should have first thing, made some calculations
of my sump size and hose volume. I want generous pumping capacity
which means 1 1/8" hose to avoid head losses in the long runs. The
volume of hose divided by the area of my sump is greater than the ON /
OFF range of any switch I have been able to locate.

I don't want to use check valves because a little bit of fluff sucked
into one could set up the endless pumping cycle. Also, if the water
drained back from the check valve, the line would essentially be
airbound.

I need a little over two inches of ON / OFF range and there ought to
be a half inch margin over that. I'm stumped. Anybody got any ideas?

--

Roger Long

I was about to respond that I am hearing pretty uniform reports of
dissatisfaction about the See Water stitch. Some report them dying in the
first month. A few with smoke and enough heat to melt the case.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

"

Two floats. Float A is on the bottom and is the float that operates the pump
switch. It's also locked in the down position by a trigger means.
Float B is located appropriately higher up. When the water level raises
Float B it unlatches Float A. Pump runs, Float B falls, resets latch, Float
A finally falls and relocks itself.
Probably several way to implement mechanically.
Downside is added complication.
BF

"Roger Long" wrote in message
...
Those of you who read my report on my grandiose bilge system know that
I ignored the advice of the capacitance switch builder who said they
couldn't cost less than a grand and work. Well, he was right. This is
a great idea but it's not ready for prime time on most boats.

I set the whole thing up in my basement in a tub about the size of my
bilge sump with the hose let uphill to simulate the run that will go
in the boat.

Other solid state, electronic float switches have a high "On" trigger
point and a lower "Off" trigger. The See Water is instant on when
water touches the probe. Even a splashed drop seems to set it off.
There is no ON time delay at all. The instant the water drops below
the probe, an 8 - 10 second time delay starts. This is to draw the
water down low enough that backflow through the hoses won't set up an
endless cycle that drains the batteries. Unfortunately, the time delay
is totally inadequate for the length of hose run that would be found
on most sailboats.

I also noticed that the switch twice did not shut off at all and this
is while brand new and clean in a test set up. Once down in the bilge
with some stuff floating around, who knows? Fortunately, West Marine
has a great return policy and took both switches back even though I
had to hack the wires short to remove them.

I've now done what I should have first thing, made some calculations
of my sump size and hose volume. I want generous pumping capacity
which means 1 1/8" hose to avoid head losses in the long runs. The
volume of hose divided by the area of my sump is greater than the ON /
OFF range of any switch I have been able to locate.

I don't want to use check valves because a little bit of fluff sucked
into one could set up the endless pumping cycle. Also, if the water
drained back from the check valve, the line would essentially be
airbound.

I need a little over two inches of ON / OFF range and there ought to
be a half inch margin over that. I'm stumped. Anybody got any ideas?

--

Roger Long

Here is the electronic version of what you are talking about, a
latching relay.

http://home.maine.rr.com/rlma/Switch.jpg

The lower float switch goes on and nothing happens. When the top
switch goes on, current flows through the relay which closes a contact
that then bypasses the upper float switch. When the upper float
switch goes off, the relay remains on and the pump keeps running.
When the lower float switch goes back off, the circuit is interrupted,
the relay springs back, and the pump stops.

All this needs to work is a relay rugged enough to handle the current
draw of the pump without heating up or contributing too much voltage
drop. If anyone has specs handy for such a unit, I'd appreciate a
model number because I'll build this thing and report on it.

--

Roger Long

The other cool thing about relays is that they usually have multiple
contacts. If you want a cycle counter, pilot light, bell, or whistle,
it's just a matter of wiring it in. There are usually N.C. contacts
as well so, if there was something you didn't want to run at the same
time as the bilge pump, you could do that easily as well.

I'd wire the latching circuit across more than one set of contacts in
case of corrosion.

--

Roger Long

Change the circuit so that the relay coil is in parallel with the pump, and
the relay coil is in parallel with the upper switch. Any old 12V relay where
the contacts will carry the load of the pump will do.

"Roger Long" wrote in message
...
Here is the electronic version of what you are talking about, a
latching relay.

http://home.maine.rr.com/rlma/Switch.jpg

The lower float switch goes on and nothing happens. When the top
switch goes on, current flows through the relay which closes a contact
that then bypasses the upper float switch. When the upper float
switch goes off, the relay remains on and the pump keeps running.
When the lower float switch goes back off, the circuit is interrupted,
the relay springs back, and the pump stops.

All this needs to work is a relay rugged enough to handle the current
draw of the pump without heating up or contributing too much voltage
drop. If anyone has specs handy for such a unit, I'd appreciate a
model number because I'll build this thing and report on it.

--

Roger Long

I must be having an obtuse moment because I'm having trouble see what
you mean. Any chance you could sketch it?

Is this change necessary to use an ordinary 12 V. relay or just an
improvement?

--

Roger Long



"barry lawson" wrote in message
...
Change the circuit so that the relay coil is in parallel with the
pump, and
the relay coil is in parallel with the upper switch. Any old 12V
relay where
the contacts will carry the load of the pump will do.

Oh of course. Like this, right?

http://home.maine.rr.com/rlma/Switch.jpg

(I loaded the new sketch into the same URL)

I remember now the big fog lights I had on a car years ago. There was
a relay under the hood so all the juice for the big lights wouldn't be
running through the tiny switch in the panel. The relay was pretty
well sealed and intended to survive under the hood of a car so should
do pretty well if kept above the bilge water. I'll look for a couple
of those tomorrow.

--

Roger Long

OR with electric logic. Both switches closed to start.
Lo switch closed to keep running. (Hi switch is shorted out by relay in
parallel with pump)
"BF" wrote in message
...
Two floats. Float A is on the bottom and is the float that operates the
pump
switch. It's also locked in the down position by a trigger means.
Float B is located appropriately higher up. When the water level raises
Float B it unlatches Float A. Pump runs, Float B falls, resets latch,
Float
A finally falls and relocks itself.
Probably several way to implement mechanically.
Downside is added complication.
BF

"Roger Long" wrote in message
...
Those of you who read my report on my grandiose bilge system know that
I ignored the advice of the capacitance switch builder who said they
couldn't cost less than a grand and work. Well, he was right. This is
a great idea but it's not ready for prime time on most boats.

I set the whole thing up in my basement in a tub about the size of my
bilge sump with the hose let uphill to simulate the run that will go
in the boat.

Other solid state, electronic float switches have a high "On" trigger
point and a lower "Off" trigger. The See Water is instant on when
water touches the probe. Even a splashed drop seems to set it off.
There is no ON time delay at all. The instant the water drops below
the probe, an 8 - 10 second time delay starts. This is to draw the
water down low enough that backflow through the hoses won't set up an
endless cycle that drains the batteries. Unfortunately, the time delay
is totally inadequate for the length of hose run that would be found
on most sailboats.

I also noticed that the switch twice did not shut off at all and this
is while brand new and clean in a test set up. Once down in the bilge
with some stuff floating around, who knows? Fortunately, West Marine
has a great return policy and took both switches back even though I
had to hack the wires short to remove them.

I've now done what I should have first thing, made some calculations
of my sump size and hose volume. I want generous pumping capacity
which means 1 1/8" hose to avoid head losses in the long runs. The
volume of hose divided by the area of my sump is greater than the ON /
OFF range of any switch I have been able to locate.

I don't want to use check valves because a little bit of fluff sucked
into one could set up the endless pumping cycle. Also, if the water
drained back from the check valve, the line would essentially be
airbound.

I need a little over two inches of ON / OFF range and there ought to
be a half inch margin over that. I'm stumped. Anybody got any ideas?

--

Roger Long

Roger Long wrote:
Those of you who read my report on my grandiose bilge system know that
I ignored the advice of the capacitance switch builder who said they
couldn't cost less than a grand and work. Well, he was right. This is
a great idea but it's not ready for prime time on most boats.

snip

Well at least you have sense enough to recognize that if feels sooo good
when you stop hitting yourself in the head with a hammerg.

BTW, you'll never make capacitance work in that application.

I'm not going to tell you what will work since some schlock will try to
then build some cheapo version and sell it to an unsuspecting public.

Two choices, both will work.

1) Install a Whale manual pump with 1-1/2" hose. Every day, stroke that
puppy a few times.

Several benefits including exercise and it allows you to monitor the
condition of the bilge on a daily basis.

2) Install an electric pump with discharge where you can observe it.
Wire in a Son-A-Lert in parallel with the pump motor.

The more obnoxious the sound generated by the Son-A-Lert, the better.

BTW, a Son-A-Lert is just a 12 VDC, panel mounted alarm about 1-1/2" in
dia and relatively low cost available at any decent electronics outlet.

You turn the pump on, bilge water gets pumped out and you have to listen
to this awful noise.

Trust me, you will learn to watch that discharge like a hawk so you can
shut the damn pump off.

Do it every day and it will also monitor the condition of the bilge, if
you can stand the noise.

Worked for me for over 10 years before selling boat.

YMMV.

Lew