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I will post a pic when it is finished

fishheadfred attached this image:

If either the low or high level float in the sump trips the return pump and the heater shut off.They will not restart until I press the reset button.
Correction: I need to reverse the lables on the floats!

Last edited by fishheadfred at 16-Jan-2005 13:03

This is better!

fishheadfred attached this image:

Hi,
In looking at the circuit, it appears that R is the relay
coil, and R1, R2, are the relay contacts.
I'll call S1 the High level switch, and S2 the Low
level switch.

As drawn:
If S1 closes as the water level reaches too high in the
sump, the switch closes and allows voltage through what you
show as an open S2. In that case the circuit remains open
and nothing will happen. Likewise if the water drops too
low S2 will close but S1 is still open and so nothing will
happen.

With the pump and the heater on the same feed, you should
put a .01mf capacitor across the relay contacts, and
I would use two sets of contacts, wired in parallel
to handle that current.
The .01mf caps will reduce the arcing that will
occur when the contacts open (both the pump motor and
heater coils, will cause a spark as the contacts open and
the EMF collapse.) The spark will transfer metal from
on contact to the other, eventually pitting them so badly
that even burnishing them with an emory board won't clean
them up and the relay will have to be replaced.

Frank


-->>> The Confidence of Amateurs, is the Envy of Professionals <<<--

dead right frank, the low level contact needs to be normally closed . also depending on the cost of the return pump you might want to have separate contactors for the pump and heater. this will alow you to put a thermal overload on to protect the pump from burning out. and you could put a thermostat in circuit to control the heater if you need to

Looks like I did not draw what I have built.Thanks for the info!I do have it wired as you say.I will correct the schematic.I actualy wired the 110v circuit to a recepticle so the heater and pump are not in series.Thanks and I will improve the schematic.

All will be posted in the de-energized state!

OK here it is! Drawv de-energized assuming the sump is not yet filled.When filled the floats will close and then you can press the momentary switch to start the pump and heater.
Also....How would you represent the recepticle the pump and heater are plugged into?

fishheadfred attached this image:

FYI "R" is a double throw double pole relay.
Should I have the floats closed in the diagram?I guess I am asking do you show a safty tripped or reset in a de-energized schematic.

Last edited by fishheadfred at 17-Jan-2005 12:44

One more time

fishheadfred attached this image:

Hi,
I started to post and goofed.
Mark your 24vdc lines and it looks good. The normally
open level switches were what was wrong. Keep in mind
the need for the .01 Caps across the pump and heater
contacts.

Frank


Last edited by FRANK at 18-Jan-2005 08:11

-->>> The Confidence of Amateurs, is the Envy of Professionals <<<--

I am HVACR trained so everything I do is 24v ac.I still don't quiet get the need for the cap.....since I will be sending 110 to a recepticle. essentially the same as plugging them into the wall.
Thanks for the help!

Hi,
Briefly, Any device that contains a coil (motor, heater,
etc.) builds up and ElectroMotive Force (EMF) a field that
surrounds the coil of the motor.
When you turn off that device, the field collapses and
the magnetic lines of flux cut the coil and induce
a voltage in the coil. This voltage creates
the spark that you see when you pull the plug on something
that is running with a motor. A vacuum cleaner, for
instance. If you unplug an Air Conditioner from the source
instead of using the switch, and the system is running,
you will see a spark from the collapsing field.
That spark is very high voltage and current, and when
it occurs, there is tremendous heat, and some of the metal
on the contact surfaces is transfered from one contact to
the other. This causes pitting and corrosion. Continued
arcing will actually increase the resistance of the contact
as the metal is oxidized as it melts, and has a higher
resistance, which means even more heat the next time.
It's a never ending cycle, of arcing, pitting, increased
resistance, and more pitting. Eventually the contacts
become so pitted or oxidized that they will no longer make
contact, and have to be cleaned, replaced, or the relay
discarded.

A .01mf Cap across the contacts, will help reduce the
arcing as the cap is the opposite of the coil (inductor)
and "absorbs" the high current as the voltage slowly
builds. It reduces the spark.

Depending upon the design of the relay, I would devote
two contacts to the A/C feeding the pump and heater, and
I would put a .01mf tubular cap across those contacts.

Frank

-->>> The Confidence of Amateurs, is the Envy of Professionals <<<--

Very good explination.Thanks again for all the help.I will post some pics when I get the setup complete.
Just an FYI: I have a obtained a DDC automation control from work.I will be automating everythimg on the tank that I can.A contractor friend is teaching me the pogramming for it.So far I only have a thermometer for it but as sensors become available I will be adding them.I have to waitfor used stuff since the PH sensor is $1100 new for example. I will post a pic of this also when I get a chance.

Oh yeah One more question
How do I size a capacitor in future projects? mabey an online calculator?