Hi Brian
A quick circuit showing extra relay contact wiring to reverse solenoid operation.
The bits marked “solenoid” on the main circuit become these relay coils and the solenoids now connect as shown.
If the solenoids operate in reverse to what is needed, that is open when should be closed, simply reverse the connections to the solenoid.
Should be easy enough to follow as I have previously posted relay contact layout.
Any probs just yell.
Cheers Bob
Thanks Robert
Looks easy enough to connect up. Will add these in once i receive the bits and pieces.
Thanks
Brian M
Hi Brian
Yes should be easy to understand.
You are basically replacing the existing solenoid connections with relay coils and transferring the solenoids to the relay contacts. The contact circuitry is a basic voltage reversal been in use for many years with relay or switch.
All the relays are hard switched with mechanical contacts so flywheel diodes across the coils are not really a must. You can fit if you want to as they will do no harm.
Cheers Bob
Hi Brian
I am coming to grips with KiCad slowly and have been having some practice. My circuit drawing app of choice is on a Windows machine which is currently not playing the game.
I have redone the complete system schematic including the solenoid reversal relays. Note I have added a push button to start the pump if you want to do so when the water is below the top rainwater sensor. This is of course optional.
I think you should be able to read the image OK. I haven’t figured out how to upload a KiCad file yet so this is a screen shot.
I haven’t included the wiring mod described earlier to empty the rainwater tank as this will not completely empty it. I think this should be completely drained as you don’t want stagnant water in it growing bugs. I think the only sure way to do this would be with a drain cock right in the bottom. Have a think about it anyway. That mod is not hard to implement later.
Cheers Bob
PS if you right click the image you can do all sorts of things with it like take it somewhere else and enlarge it.
Sorry about the grid dots, forgot to turn them off
Should have added this
Hi Bob,
This is great, i was actually sketching this up by hand and yes it makes it a whole lot easier to follow. Wasn’t expecting this but really appreciated and can’t thank you enough for the assistance and the schematic.
Yeah, I’m just going to put drain cocks on all the tanks at the moment as they should be cleaned and drained at least once a year.
I did come across some solenoid valves that close once power is removed but I’ll run with what i have at the moment.
Thanks
Brian M
Hi Brian
The only down side with the ones you have is that they will be powered one way or the other while ever power is applied. So you will need to make sure that the main switch is off at all times when not in use or you could find yourself with a flat battery. But that should not be a problem once you establish a routine.
Cheers Bob
PS: I assume you DO have a low voltage shut off device fitted to your whole van set up don’t you. This is to prevent damage which WILL happen if you allow your battery to over discharge (10.8V for lead acid, usually set for 11V)
We are getting a new van built with 48v lithium can bus batteries full automated system and yes it has over voltage and under voltage protection. As it is full automated i will be able to control the water pump system via the control pad.
Thanks
Brian M
Hi rian
That sounds pretty good. I hope you can find 12V somewhere for all of this. You did not mention 12V in the first place so as I was assuming 12V and sprouting this everywhere and as you did not correct me I assumed everything was 12V. This is the first time 48V has surfaced so I hope there is a 12V output somewhere to use.
Cheers Bob
Yes, it is still is a12v system throughout the van just the main power source is 48v to ensure quick charge/recovery and less draw on the 240v power source. It steps down from. 48v to 12v
Thanks
Brian M
Hi Brian
That looks good. Something new to me but there again I am not into Caravans. In that case you can discount comments above re low voltage shut down as no doubt all this will be taken care of in your complete system.
Cheers Bob
Hi Rob
Hope you are well. I’ve finally got my automated water pump system connected and working, been a bit busy with other things so only just finished setting it up.
Just want to check a couple of things with you on how this is a all wired up.
Scenario: Rain tank receives water, enough to start pump, pump is a on demand pump.
I find that once tere is enough water to start the pump i find the main tank solenoid valves open to allow water in regardless if needed or not, is this correct. Why is there a top level sensor on the rain tank as it doesn’t disconnect the pump when the rain tank reaches the top water level sensor, not an issue but it holds the solenoid valves open on the main tanks.
The main tank solenoid valves only close when the rain tank is below the bottom water level sensor.
Is there a way to have a top and bottom water level sensor on the main tanks which close the solenoid valves when it reaches the top/full level and opens when it reaches the lower level and stays open until the tanks are full and naturally enough water in the rain tank to keep feeding the system.
Hi Brian.
We will start with the first bit.
Rain water tank… The bottom sensor operation enables the whole system. Without enough water in the tank nothing can happen. When the top sensor operates the pump starts provided both tanks are not full. The pump relay latches via one of its own contacts in series with one or both top of tank sensor relay contacts. While either or both tank sensor relays is not operated the bump will remain on until the bottom rain water sensor releases then the pump will not start again until the rain water tank reaches the top sensor. The pump will stop when BOTH tank sensors activate.
Main tanks:…The default inlet valve position is open. When the rainwater bottom sensor activates the system is enabled. when the level reaches the top sensor the pump will start and remain latched as described above. Water will be pumped into both tanks until one fills, sensor activates closing that valve and allows the other tank to fill without wasting with first tank overflow. When both tanks fill both valves will be closed the pump will stop. This will also release the latch so the rainwater tank will have to fill (up to sensor) again before the pump can restart.
The press button (optional) is included in case there is a requirement to start the pump before the rainwater tank fills.
Note at least one of the tanks has to require water, ie; at least one sensor not activated before the pump will start.
Your problems
I just printed a copy of that circuit and you could have made an accidental error. With my print there seems to be a connection between Rainwater top sensor relay NC and NO. That connection is not made on the KiCad circuit and seems to be how the dashed line printed. If you have done the same you might have made this connection. If so remove it. This would cause no end of bother
Solenoid valves. These should default to open and only be closed when the tank is full. ie whenever the tank requires water they should be open whether the pump id running or not. You may have connected them backwards. If so reverse the connections.
T0p rainwater tank sensor. This starts the pump which will continue until rainwater tank empties or both main tanks are full. Whichever comes first. It does not stop the pump
Hope this helps. Cheers Bob
Hi Rob,
Thanks, that explanation is great and i think i have the solenoids wired wrong to start with, but will check.
The issue I’m having is with the rain tank level relay and pump circuit.
I have wired the sensor and relays as per you diagram, and no i don’t have NC and NO of the top sensor relay connected, i picked this up when i looked at the schematic when you first sent it through.
The pump relay won’t release and stays latched, even if the main tank solenoids operated, unless the water level is below the bottom sensor.
Also, the solenoids on the main tanks will not close when the water level is above the level sensor, which i think will be related to the pump relay and rain tank level relay.
I’ll have another look at this and see if i haven’t missed something in the wiring but i don’t think so.
I haven’t included the push switch on the level sensor relay circuit as yet and makes sense to have it in case it is required.
Thanks
Brian M
Hi Brin
I will have another look at this. I am sure I am correct. The pump relay should release when BOTH tank sensor relays operate. That will (or should)remove the ground return connection from the pump relay coil.
Will study to-morrow.
Cheers Bob
Hi Rob,
Thanks, no hurray on the issue as i won’t be able to do much with it until Monday.
I’ll look over the schematic and wiring again myself just in case i missed something or wired something up wrong but i don’t think so.
Thanks
Brian M
Hi Brian
I have had a look at the circuit.
Firstly lets identify the relays by number to simplify things. My fault, should have done this from day 1.
Start at top left of circuit. Pump ON/OFF = RL1, Rain water bottom = RL 2, Rain water top = RL 3, Tank 1 top = RL 4, Tank 2 top = TL 5, Solenoid tank 1 = RL 6 and Solenoid tank 2 = RL 7.
There are 3 possibilities that could cause these results.
S3 and S4 in that circuit becoming the relay module contacts for RL4 and RL5. The idea being that the rain water tank would empty via one of the main tank overflows. This was later discarded as the tank would not completely empty and a residue could cause health problems so you were going to fit drain valves to allow for complete empty manually for cleaning.
Now if these links are fitted (as I said, unlikely) the pump would behave as you described. IF they happen to be fitted remove them.
There is a wiring error. This is also unlikely as you seem to have done plenty of checks.
One or both RL4 and RL5 not operating when the tanks fill. The NC connections of these relays provide the final path to ground for RL1 via RL2 and RL1 latching contacts and the 2 diodes. When BOTH RL4 and RL5 are activated this path is broken and RL1 will release.
Within option 3 there are a few possibilities.
One or both sensors are not operating.
If BOTH relays are not operating and the sensors are OK the common denominator is the 5V supply to the module, Is this OK. Do the indicator lights come on when the relay is supposed to be activated
And make sure the terminal connections of these relays are not clamped down on the wire plastic insulation. This problem is more common than you might think. One reason is why I advocate using bootlace ferrules in these situations. Pretty much removes errors like this not to mention wire damage caused by the clamp screw if wire protectors are not used in the terminals (like some of the cheap types)
A bit of detailed sleuthing with a Multimeter will probably be needed here…
I suggest a small wiring change to reduce the time that RL6 and RL7 are actuated. They will only be active when the tanks are actually FULL.
The new scenario is when the tank is full relay actuated. Any other condition (not full) relay is idle. This will reduce the ON time for these relays.
This involves connecting the LOW side of TL6 coil to RL4 NO contact and the LOW side of RL7 coil to RL5 NO contact. The diode cathodes still connect to the NC contacts of RL4 and RL5.
Circuit changes.
This might remove any confusion with the way I have presented RL6 and RL7 which are drawn in the idle state and the contacts on RL4 and RL5 show they should be activated. This as well as reducing the ON time.
If the valves are working correctly now you will have to reverse the solenoid connections. Tank requires water = valve ON. Tank full = valve OFF. This is the situation at all times irrespective of what the rain water tank status is.
I will modify the KiCad circuit and post in a couple of days.
Cheers Bob
Hi Robert,
Thank you for getting back to me. I will have a look at No 3 scenario tomorrow and run a couple off checks with a multi meter. I have been checking with a multi meter throughout and haven’t noticed any anomalies.
All the indicator lights come on when the relays are activated so I would guess they are all working. I will also check the wiring again, as i mentioned, just in case i have wired something wrong, the only thing i can think off is, maybe i have connected the diodes the wrong way, i will also check that as well.
With the change you are suggesting will this make the pump cycle more? Not that this is an issue just curious.
Thanks
Brian M
Hi Brian
Here is the revised circuit
Take noe of the slight changes. As mentioned you will probably have to reverse the solenoid connections. The requirement is tank is below top sensor = valve open, tank at or above top sensor (sensor and relays RL4 & 6 /RL5 & 7 operated) valve closed.
I don’t believe so or RL1 would not latch as there would be no path to ground. They are there to isolate RL4 and RL5 and sort of provide an “AND” function ie; RL4 AND RL5 have to operate to unlatch RL1. What diodes have you used by the way. They have to handle a little bit of current (relay coils) so probably the readily available 1N400X series OK.
Are they but?? If you rewire as per latest version (above) you can easily check. If you measure the NO contacts of RL4 and RL5 to ground you should measure 12V with relay at non active state and 0V when activated.
NO. If you look at this closely you will see that solenoid control is independent of pump operation except for utilising the NC contacts for RL1 unlatching. While ever the system is powered the valve solenoid should be positioned to whichever position is dictated by the tank level sensor states. Irrespective of what the pump is doing at the time.
Cheers Bob
Hi Robert,
Will make the change as per revised circuit.
Yes, i have used 1N400X diodes.
Will check all the voltages and also check that the indicator lights are coming on.
Okay, makes sense will keep you posted on progress.
Thanks again for your assistance.
Thanks
Brian M
Hi Robert,
Well, made the changes and checked all wiring and voltages all checked out.
Did test run and all worked as described in your email, not sure what was the problem, maybe holding my tongue wrong lol.
Thank you so much for your time and patience it is greatly appreciated.
Thanks
Brian M
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