drummerrhys Posted June 16, 2008 Share Posted June 16, 2008 Hey all, The George Sampson thread got me thinking about a gig I have in about a months time.I have a load of powerful pumps for founds (about a dozen) which need to be sunk into a pool and then go off at different times.I was wondering if there was anyway I could control or sequence this, or if I am just going to have to let thefountains do their own thing and try and make it look good with the lights? Thanks in advance,Rhys Link to comment Share on other sites More sharing options...
Bryson Posted June 16, 2008 Share Posted June 16, 2008 Possible? Why yes. Cheap and easy? Probably not. DMX relays might be a way forward... Link to comment Share on other sites More sharing options...
cedd Posted June 16, 2008 Share Posted June 16, 2008 As far as I recall from a documentary on tv a few years ago, your main problem will be the delay between turning the pump on and the water actually appearing. I believe the guy in this documentary was turning pumps on a beat before they were needed so the fountain turned up at the right time. He did it with a panel of push switches - nothing spectacular. You could perhaps do something fancy with timecode to que a lighting desk running DMX relays a beat ahead. Link to comment Share on other sites More sharing options...
JimWebber Posted June 16, 2008 Share Posted June 16, 2008 Now, this is a project I have been dreaming of for years, (And one day, I will actually find the right show, (with the right budget) to actually do it. My plans are to have the pumps running continuously, but control the water flow with some solenoid valves, again via a DMX relay or a switch pack, (ALthough I realise there may be all sots of problems using a switch pack, not least the back emf from the solenoids.) Jim (Who is dreaming of one day!) Link to comment Share on other sites More sharing options...
bruce Posted June 16, 2008 Share Posted June 16, 2008 I'm sure we've been here before.... ...searches... Hmm- I was thinking of this thread but it's a lot briefer than I thought... Summary - Maybe try a DMX switch pack and some washing machine solenoid valves. Maybe need a dummy load across the solenoid to reduce the effect of the back EMF? Link to comment Share on other sites More sharing options...
d_korman Posted June 16, 2008 Share Posted June 16, 2008 I'm sure we've been here before.... ...searches... Hmm- I was thinking of this thread but it's a lot briefer than I thought... Summary - Maybe try a DMX switch pack and some washing machine solenoid valves. Maybe need a dummy load across the solenoid to reduce the effect of the back EMF? One would normally use a diode. Link to comment Share on other sites More sharing options...
Ike Posted June 16, 2008 Share Posted June 16, 2008 For an AC solenoid, no they wouldn't! There's also this very similar thread. I suspect with the solenoids being such a small load you shouldn't need a dummy load if using relays. Link to comment Share on other sites More sharing options...
drummerrhys Posted June 16, 2008 Author Share Posted June 16, 2008 One of these Jobbies? Valve Link to comment Share on other sites More sharing options...
DMXBandit Posted June 16, 2008 Share Posted June 16, 2008 We use DMX switch packs for this. Yes there is a delay between switching it on and the water coming out, but once you've got them going they will be much more responsive, that is until you leave them turned off for 20 seconds or so. It will help greatly if you use non return valves on the pumps, so the water doesn't drain back down during the off time and stays in the pipes ready to go! If you have 3 phase pumps then you can use an inverter to keep the pumps running at a low speed (just bubbling over), then ramp them up to get instant results. Its quite an expensive route to go down but the ability to change the hight of the fountains looks much better than just switching on and off. Link to comment Share on other sites More sharing options...
Ike Posted June 16, 2008 Share Posted June 16, 2008 If you have 3 phase pumps then you can use an inverter to keep the pumps running at a low speed (just bubbling over),No reason the pumps have to be three phase. Link to comment Share on other sites More sharing options...
Jivemaster Posted June 16, 2008 Share Posted June 16, 2008 The usual method of doing this is to use a single huge pump, - Think the luggable one that goes under a fire engine for remote work, - prob 30 - 50 bhp and petrol powered. Then the output is sent down a single pipe joiner by fire brigade couplungs. The working pressure will be up to 100psi and the available flow rate huge. This is then controlled by solenoid valves, perhaps low volts for ip rating and water safety. Control by DMX or any plc computer. In your situation trying to get pond pumps to dance by controlling the motors is unlikely to work fast enough, prthaps work at all. Link to comment Share on other sites More sharing options...
DMXBandit Posted June 16, 2008 Share Posted June 16, 2008 If you have 3 phase pumps then you can use an inverter to keep the pumps running at a low speed (just bubbling over),No reason the pumps have to be three phase.My bad, I was still in work mode, all our single phase pumps are on switch racks and our 3 phase on DMX'ed inverters. Incidentally, I spent a couple of days looking online for a speed controller (ideally DIN rail) for single phase pumps. Do the motors have to be synchronous or asyncronious, or will either work (I know what the difference is, but not why it matters). If anyone could recommend one that would be really helpful. Being a lampy at heart I'm still quite new to AC motors, I'm more used to steppers and servos! Link to comment Share on other sites More sharing options...
boatman Posted June 16, 2008 Share Posted June 16, 2008 One of these Jobbies? Valve Yes, that should be fine as long as it is truly a solenoid valve and not a motorised valve as used in central heating systems. You also need to be careful to operate the valve in a dry environment which will mean piping the water away from the storage pond and back again to the fountain. How are your plumbing skills? Link to comment Share on other sites More sharing options...
Ike Posted June 16, 2008 Share Posted June 16, 2008 You may well find using washing machine valves works out a lot easier in terms of plumbing as you can do everything with flexible hose an jubilee clips. Of course I would emphasise the importance of keeping water away from the mains. Incidentally, I spent a couple of days looking online for a speed controller (ideally DIN rail) for single phase pumps. Do the motors have to be synchronous or asyncronious, or will either work (I know what the difference is, but not why it matters).As far as I know either synchronous or asynchronous (induction) motors should work however I only have experience of using the latter in this way. Unfortunately though there's a complication. As you probably know getting single phase motors to start reliably requires a few tricks, many motors use a centrifugal switch or external relay to switch out a starting circuit once the motors spinning however these aren't really compatible with variable speed drives. For variable speed you really need a capacitor-run (permanent split capacitor) or shaded-pole motor, other types sometimes work but it can be a bit hit and miss especially at lower speeds. If anyone could recommend one that would be really helpful.Invertek make a number of single phase drives, you might want to look at their Optidrive E1 to get you started. Of course when it comes to speed control (or any motors for that matter) three phase or DC is always better than single but I'm guessing you already know that. ;) Link to comment Share on other sites More sharing options...
Jivemaster Posted June 16, 2008 Share Posted June 16, 2008 Valves with 24v solenoids make safety easier! Loads of IP68 connectors and run the wires back to the controller in a dry box with glands. For the OPs job in hand this is OTT! there seem to be some small submersible pumps! you wil want all you can get from them, not some off time Link to comment Share on other sites More sharing options...
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