Diagram for auto topup

[Tangman]

Here is a diagram for an auto topup it has been drawn by me but modified by Johnl69. I hope you can make us of it. EricRe: auto top up system.
<HR style="COLOR: #d1d1e1" SIZE=1><!-- / icon and title --><!-- message -->http://i85.photobucket.com/albums/k48/johnl69/IMG_0001-1.jpg
http://i85.photobucket.com/albums/k48/johnl69/IMG-1.jpg

[stegoodall]

so the relay is switching the mains rather than the float switch

[Tangman]

so the relay is switching the mains rather than the float switch
Hi Thats it its so you dont have 240 volt going through the float as i think John said it would burn the float out. HTH Eric:D

[stegoodall]

i presume it also means keeping 240v away from the water i,e, the float switch....which can only be a good thing :D

[trik]

i presume it also means keeping 240v away from the water i,e, the float switch....which can only be a good thing :D

LOL but your pump is still mains voltage, as is the rest of the kit in your tank, there are float switches on the market that will switch over 1kw.(1000 w)

[Tangman]

LOL but your pump is still mains voltage, as is the rest of the kit in your tank, there are float switches on the market that will switch over 1kw.(1000 w)
Hi Richard thats true m8 , but i think the trouble was putting 240volts through a floatswitch that was not rated to take that amount of power. HTH Eric:D

[MR Teee]

You dont want home made connections running 240V anywhere near the salt water IMO.

Unless of course you are a qualified electrician, then you can take the risk whilst knowing the dangers.

[trik]

hi mate,most float switches if not all will switch over 15w from RS or Maplins, the ATU im using came from kenslovechild from the other bb and he sells them on ebay, i just copied the parts and built myself a spare, 100% perfect , and wired up like your diagrams Eric, but with no transformer.

[trik]

You dont want home made connections running 240V anywhere near the salt water IMO.

Unless of course you are a qualified electrician, then you can take the risk whilst knowing the dangers.


HE HE bonus for me then, but if you put all connections in a IP64 rated box , you will be safe .

[MR Teee]

Just incase you want an easy life, here are the components from Maplin.

Power supply:

http://www.maplin.co.uk/Module.aspx?TabID=1&ModuleNo=49063&doy=5m6

Float Switch: - (Maplins only have Horzontals)

http://www.maplin.co.uk/search.aspx?MenuNo=12898&MenuName=Float+Switch&FromMenu=y&doy=5m6

Relay

http://www.maplin.co.uk/module.aspx?ModuleNo=37518&doy=5m6

[trik]

Made by Honeywell

http://cpc.farnell.com/jsp/search/productdetail.jsp?sku=SN35985

[MR Teee]

Another Vertical float switch:

http://uk.farnell.com/jsp/Industrial+Controls+&+Automation/Flow+&+Level/GTI+(GENTECH+INTERNATIONAL)/FVCS-02/displayProduct.jsp?sku=1006795

[trik]

As i said if you look around there are loads.:)

[johnl69]

The idea of a relay is so that a high(er) load can be switched by a switch with a lower rating than the load be ing switched.

Both those float switches are rated at 1Amp MAX so therefore they cannot safely switch a load above 1Amp, most power heads will pull over 3Amps when starting up a load 3 times higher than the switch is design for NOT SAFE!.

Question; How many times a day will the float switch turn on and off?

Once? Twice?

A float switch is a reed switch that work in conjuction with a magnet, the magnet floats on the surface of the water as it rises to wards the reed switch the contact slowly close if your putting 3 times the amp through the switch then a spark will occur across the contact before they close if the water if not perfectly level then this happen quite a few times in a short space of time, These spark generate heat and can "weld" the contacts together which inturn creates heat, the more heat the more amps a system draws creating more heat this continues until the fuse blows, Now say your using a 13Amp fuse in the plug the amount of heat that this situation can create is enough to melt the plastic casing of the switch which leaves 240v live in your tank.

Best case sinario; the float switch stays on and you flood the floor.

Worst case sinario; The float stays on melts the plastic casing floods the floor any leaves 240v live through the water!

Surely for the sake of an extra £10/15 and the peace of mind of knowing that there only 12v in the water is it worth risking yours and your families life?

[MR Teee]

Totally agree John, I only recommend the parts listed are used in the diagrams above and no other methods.

I said it before and I'll say it again, unless you are qualified, keep the 240V well away from the tank in any home made applications. 12-24 is sufficient for almost anything when you are using a relay.

[trik]

The idea of a relay is so that a high(er) load can be switched by a switch with a lower rating than the load be ing switched.

Both those float switches are rated at 1Amp MAX so therefore they cannot safely switch a load above 1Amp, most power heads will pull over 3Amps when starting up a load 3 times higher than the switch is design for NOT SAFE!.

Question; How many times a day will the float switch turn on and off?

Once? Twice?

A float switch is a reed switch that work in conjuction with a magnet, the magnet floats on the surface of the water as it rises to wards the reed switch the contact slowly close if your putting 3 times the amp through the switch then a spark will occur across the contact before they close if the water if not perfectly level then this happen quite a few times in a short space of time, These spark generate heat and can "weld" the contacts together which inturn creates heat, the more heat the more amps a system draws creating more heat this continues until the fuse blows, Now say your using a 13Amp fuse in the plug the amount of heat that this situation can create is enough to melt the plastic casing of the switch which leaves 240v live in your tank.

Best case sinario; the float switch stays on and you flood the floor.

Worst case sinario; The float stays on melts the plastic casing floods the floor any leaves 240v live through the water!

Surely for the sake of an extra £10/15 and the peace of mind of knowing that there only 12v in the water is it worth risking yours and your families life?


Im very sorry but what sort of power head do you use for your top up, AM6500 :eek:, most small PH are around 7/10w thats no where near and 1amp do your maths and you will see,:D, as for the ATU it only needs to be very slow like a drip every second.

Richard

[johnl69]

i dont use a powerhead for top up i use a electronic shut off valve on my R.O unit, the pump i tested with an ampmeter was a mp600,

trik, Why do you need a spare top-up unit?

[trik]

As its allways good to have a spare, i spent years in the elec maint buisness and its a bit of a habbit, you never know when somthing is needed, and at a loss of over 100k an hour i kept spares that didnt go down for years, better than called to the bosses office for a grilling, so i keep at least 1 spare for everything, that way fish and corals arnt going to but me through to much of a bad time:D

[gturnbull]

Hi All,

Just a small note on the auto top up design.

If you just switched the live on the Relay, you would get a longer life span on the relay, instead of switching both the live and neutral supplys on the contacts

[stegoodall]

would that need an SPST relay instead then?
thinking of making one for when we go on holidays......would be tested before though :)

[angel1]

Is that supposed to make sense?:confused:

LILYANN:p

[steve123]

yes but no need for blocks lol

[gturnbull]

would that need an SPST relay instead then?
thinking of making one for when we go on holidays......would be tested before though :)

You could use a SPST or just use a DPDT and link them across, if you can't get a SPST.

[stegoodall]

what does that mean? use both "poles" for live?
not really clued up on this lol, just the basics. i'm quite good at wiring ballasts and lights up though lol

[johnl69]

what does that mean? use both "poles" for live?
not really clued up on this lol, just the basics. i'm quite good at wiring ballasts and lights up though lol


Like this :D

[stegoodall]

ok but if i was using a DPDT then wouldn't it be best to just switch both live and neutral? not sure what the point would be?

[johnl69]

ok but if i was using a DPDT then wouldn't it be best to just switch both live and neutral? not sure what the point would be?

Personally Ive always used DPDT relays when switching mains, for me its gives complete isolation but each to there own :D

[stegoodall]

wheres the best place to get the right parts then? maplins is usually expensive compared to other places, i'm sure i have a 12v adapter lying around somewhere that i can use, what would i need to buy?
float switch
mains plug socket (for pump)
relay
some kind of box for it (not sure what type etc)

can i put the adapter in the box and just use one mains supply (split it to the transformer and to the relay/powerhead)?

[johnl69]

PM for you:D

[stegoodall]

cheers for the info and help john, my dad asked the other day how i could make one with the extr switches, am i right in thinking they are just in series? so all have to be closed to turn the pump on. if any are open i.e sump too high or top up barrel too low then it wouldnt work.

[johnl69]

cheers for the info and help john, my dad asked the other day how i could make one with the extr switches, am i right in thinking they are just in series? so all have to be closed to turn the pump on. if any are open i.e sump too high or top up barrel too low then it wouldnt work.

Due to the switches being "open" when the switch is up then the RO switch will only be closed if the water is low, Google "NOT Gate" :D

john

[stegoodall]

oh no logic gates lol, just done a module at uni with these in haha

[stegoodall]

i'm thinking a NOT gate effectively inverts the switch, i'm sure i read that switches can be changed to normally closed or normally open by turning the float around. could i just turn the float instead of using a gate?

[stegoodall]

any chance you still have those diagrams lying around eric?
:)

[cl0wn]

this is why i hate photobucket, the images were linked to john69's photobucket account, may be worth pm'ing him to see if he still has them.

[Cookie]

any reason for not switching from just neutral side.

Simon

[ROB]

i'm thinking a NOT gate effectively inverts the switch, i'm sure i read that switches can be changed to normally closed or normally open by turning the float around. could i just turn the float instead of using a gate?

That's true I am no expert but read the same,

Rob.

Did I just answer a very old post.

[Dons1903]

Don't suppose anyone has a copy of these diagrams? The links are broken and it appears that they were john69's who is just showing as a guest now :-(

Craig

[Tangman]

Don't suppose anyone has a copy of these diagrams? The links are broken and it appears that they were john69's who is just showing as a guest now :-(

Craig
Hi Craig no m8 i had a copy saved on my old lappy but it went to the big hole in the sky last year and Johnl69 is no longer a member so its a bit of a bummer im afraid unless someone else has one. Twiggy