pump turning on in every cycle (tag)

herbgro

Active Member
i´m baffled why my tag pump is turning on in every misting cycle as i have pressurized bladder tank hooked on it, does anyone know what is wrong, or missing from the setup?

my setup is aquatec 8800 pump whit eso and tso harvest wich makes the pump stop at 60psi(4.1 bar) pressure when the tank is full and i have 16 pieces of mist nozzles which have max flow of 0,89 gallons each in one hour, as all together 14.6 gallons in hour, but as i run 1-2 second bursts it should be 0.23 gallons in minute and 0.0039 gallons in one second, and i have 1.3 gallon pressurized bladder tank which on my calculations should take loads of start and shut off cycles before the tank runs off the pressure. somebody please help me...
 

Atomizer

Well-Known Member
Figure out the cut-in point of the TSO and make sure you have the bladder tank air precharge set to 2psi below that, For example if the TSO starts the pump at 40psi set the precharge to 38psi.
The TSO and ESO switches are designed to shut off the water supply to the pump and the RO water feed to the tank (when the tank pressure = 60psi), ideally you should use a proper pressure switch with adjustable cut-in and cut-out (psi) to control the pump.
I use Italtechnica pm-12`s but anything similar will do the job.
http://www.italtecnica.com/index.php?ip=4&cat=2&prd=7&l=2
 

herbgro

Active Member
i see, i was on impression that my water tank holds the pressure at 60 psi constantly until there is not enough water on it and the pump would only turn on when the 60 psi pressure is gone whit the water in the tank and the pump would not react to it, would this work if i install one way check valve between tank and pump? or is the tank too small to work like this, if not maybe i could get away from buying new pressure valve by just buying like 14 gallon tank?

that list of pressure switches what did you link earlier has those ampere ratings, is that how much the switch can take from pump or how much the switch needs to operate? i have 10 A fuses in my house...
 
Last edited:

Atomizer

Well-Known Member
Its how much the switch will handle,16A@240v is more than ample.
The tank will only be at 60psi after the pump has charged it, when its empty it will be at the air precharge pressure (eg 38psi)
A 1.3 gallon tank with a 38psi air precharge will need 0.382 gallons (1.45L) of water to bring the tank pressure upto 60psi. The water compresses the air in the tank to make room for the water being pumped in. As you use the water, the air expands to fill the space left by the water and its pressure drops.
A pressure switch turns the pump on at the cut-in pressure (40psi) and off at the cut-out pressure (60psi), the air precharge is set 2psi below the cut-in pressure so the tank is never completely empty before the pump kicks in. At 40psi, you`ll have about 180ml of water left in the tank.
Large tanks are controlled in the same way as a small tank, they just hold more water.
 

herbgro

Active Member
i though to run nozzles between 45 to 65 psi, i looked up some pressure switches and they only cost 20 $ on ebay so i probably order one from there.
i found 13 gal tank on sale on local site, at 120 $ and 6.6 gal on 26 $ bigger would save pump but are very expensive, but probably i save money on long run still as pump don´t have to start and stop so much.
 

Atomizer

Well-Known Member
45psi is pretty low for hp, 60psi is a good minimum if you can manage it. I run the tank 140psi down to 80psi, a pressure reducer after the tank governs the output to a constant 80psi. A big tank on a small setup will run for days, which gives you the option of charging it manually (no pressure switch required)
 

stacatto99

Well-Known Member
where does one find a small tank that can maintain 80 to 100+ psi? i've been looking at shurflo but they dont seem large enough.
 

Atomizer

Well-Known Member
Most tanks are rated at 100psi or more,the spec sheet will give you the tanks maximum working pressure. If you run a small recirculating setup you wont need a huge tank, the pump will just run more often. Bigger tanks are great for larger setups and run to waste, the tank works as a pressurised res and you just fill it up when its empty. I top mine up once a day (5 minute job) so it never gets that low.
 

Mike Young

Well-Known Member
You can easily pick a a small 2.5 gallon or so tank from any hardware store. They're in the water-heater section.
 

herbgro

Active Member
i thought that would be best way to save money on maintaining,t it would be good if pump had to only start few times a day so it would last years.
maybe i run up to 60 or somewhere 55 psi lowest point as atomizer advice´d, but even the pump can push 80 psi still the pressure gauge seems indicating to dropping of pressure as loaded 80psi and then settling in few minute to 70 - 65 psi, there is no any leak or water comes from nozzles, i wonder where the pressure goes? tank is rated for 145psi/10 bar.
i got push-in fittings from pneumatic company in china, don´t really know is there any difference to hydraulic one.
put if there is no water leaking out piping anywhere how can the pressure drop?
 

Atomizer

Well-Known Member
The pressure drops due to losses in the system, for example, a run of 1/4" tube will incur more loss (pressure drop) than the same length of 1/2" pipe at the same flowrate. The higher the flowrate (GPH) the higher the loss. Every fitting and sharp bend in the system will add to the loss.
Design the system to minimise losses by using larger bore tubing between the tank and the solenoid(s). This pipe incurs the highest loss as it supplies the entire flow for everything downstream. Using smaller tubing after the solenoid(s) is ok as long as the nozzle manifold arrangement is designed to minimise losses. For example, a ring manifold arrangement will feed from both ends (half the loss of feeding from one end of a single pipe).
A parallel manifold (like an air pump multi-output manifold) can feed individual nozzles, each tube carries the flow for one nozzle. In your case, this will be 16x less than the pipe supplying the solenoid from the tank.
The first thing to do is to run one nozzle into a measuring jug for one minute at your desired working pressure (60psi etc) to see what the real gph flowrate is (multiply whats in the jug by 60). Its best to repeat the test with a few nozzles and take the average. That will give you the (lossless) flowrate your plumbing needs to deliver. If you design it right you will get the 15+psi loss down to a couple of psi.
 

herbgro

Active Member
i got piping from 3/8 tubing and use one T fitting part to make Y shaped piping which each end has 8 nozzles in length of 4-5 foot hosing whit T-fittings of 15 all together in hole packet.

i just wonder if there is just a foot of the pressure gauge tubing each side, and each side has also solenoids and has pump on between them too along side of bladder tank and pressure gauge, other solenoid is in output whit the timer and other is hooked whit the sensor which closes intake.
there is no in any water leak, how can the pressure go down even the system is in non working mode?i mean no spray cycles both end of the hose is locked by solenoid and still pressure drops...

it still works right way whit 60 and 65 psi as i meant it to work and is holding the pressure until solenoid releases the pressure to the nozzles, put if adjust pumps to 80psi as (15 psi more) then pump shutdowns in 80 psi system in pause and pressure drops to somewhere 60-65 psi.
the pressure gauge has about half foot tubing way to the bladder tank which has bigger opening inside the solenoid than tubing normally as the bladder tank T part is both about 20mm or in inches 0.78.
 
Last edited:

Atomizer

Well-Known Member
Could be a few things but rebound from the tank diaphragm is the favourite, high flowrate pumps coupled to small capacity tanks can outrun the elasticity of the diaghragm (ie the diaghragm takes a few moments to settle) when the pump stops pushing. If you are aerating the nutes in the reservoir that feeds the pump with airstones, you may have entrained air going into the tank along with the nutes. The entrained air is compressed by the pump before it enters the tank so it adds to the overall tank pressure without adding any water. The air is absorbed into the water which reduces the overall volume in the tank. The air cushion expands to take up the slack and the tank pressure drops.
Pressure drop due to entrained air doesnt usually amount to more than a few psi, so the diaphragm rebound seems the more likely cause. To test for entrained air, run some water off the tank into a glass just after the pump stops, it`ll look white/cloudy. Do the same test again a few minutes later and it should look crystal clear.
 

herbgro

Active Member
i don´t use air stones, only thing what could aerate the water is the drip rings, though i have 50gal reservoir (220l)
and water is circling now before i get it to run and waste type so i don´t think the reservoir is much oxidized as the system did the same thing as i put inlet tube to bucket of water what took out from tap.

pump instructions said that its better mount it as head up as that way the pump should not trap air and that way it i installed it, also i mounted the tank as water leaving from up way as the bladder is in the bottom,so maybe the air will be the first leaving the tank?

maybe the tank may have too much pressure? as i filled it to 58 psi in start (4bar) but since then i have released the air from it several times to the point that the pump seemed filling it, as i filled it and run all the water from the tank to container i got like 0.25 gal (1.1 L) whit 60psi, whit 80 psi it used more cycles before pump started so probably it filled it better, did not check amount of that one yet.
i have to wait that pressure switch before i can continue, whit low budget i probably get some cheap one from china next week.
 

Atomizer

Well-Known Member
Pics would be useful but i suspect the pressure switch is the cause of most of the issues.
The first thing to do is to figure out if the pressure switch turns the pump "on" (cut-in) at a set pressure (ie 60psi) and "off" (cut-out) at a set pressure (ie 80psi). Once you have the "cut-in" pressure, empty the tank of nutes completely and leave the pipework open to the air (open a drain valve etc). Pump air into the tank via the schrader valve until you have 2psi less than the cut-in pressure, so if the pump cut-in was 60psi, set the (precharge) air pressure to 58psi.
When you refill the tank with nutes, the water pressure guage will jump from zero to 58psi (or whatever you set the tank air precharge at) almost instantly. A 1.3gal tank will take approx 1.14L of nutes to go from 58psi-80psi.
My tank`s air precharge is set for 78psi, pressure switch is set for 80psi cut-in,140psi cut-out which takes around 40L of nutes.
plumbing.jpg
 

herbgro

Active Member
i don´t have any camera as old one has dated out.
my pressure switch pipe adapter fitting came this week and i had today time to hook it up. i took your advice and set pressure much higher, from 85psi to 55psi, only thing what crossed my mind after i was all ready ordered this current 230 volt switch, that the pump is working on 24v, so now i had to wire the pressure switch control the 230v transformer instead of the pump
.
what do you think how long the transformer will last if it is switched on and off every hour for 5-10 seconds at time. 24v switcher would save the transformer, then again i could save the cost of couple transformer as saving electricity when the transformer is not on continuously. though when i noticed this i try´d to look up from ebay any 24v pressure switch whit very poor results, are you using 24v pressure switch?

i`m pretty satisfied to get the system working after long time saving money and searching info, i only need bigger bladder tank and i have the final heart of the system ready, though i don´t want stop the hobby of pimping more and more :)
 
Top