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can someone please explain what pump calibration dose
- Thread starter Dragbag
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The pumps we use for window cleaning most have a built-in mechanical pressure switch that cuts power to the pump when the pressure in the hose gets to 100psi.
Here is a copy of @Ian Sheppard's explanation posted on another forum last year.
Why calibrate the controller to a pump?
What we are doing is telling the controller what the maximum pressure the system normally operates at. To get a good flow at the brush head the system is probably running between 40 - 70 PSI. So the controller knows that the normal max level is 70 PSI. When a user stops the water flow the pump will attempt to push against the restriction increasing the pressure above 70 PSI the pump sees this sudden rise and stops the pump. This is what we refer to as DEAD END (DE).
When flow is stopped EG the pole tap is turned off. Two things happen
1. Pressure builds up in the line
2. Current draw by the pump spikes
In normal operation the Pump will draw around 3 – 5 amps with system PSI stable as the system is in open flow. Stopping flow means the pump draws a lot of current very quickly and the system pressure rapidly builds. As above the control see,s this sudden change and stops the pump DE
During this DE (flow stopped period) the controller retests the pressure at the pump every three seconds.
During the DE retest the controller will briefly pulse the pump for a fraction of a second some operators will hear the pump blip. The Controller is designed to carry out this test but importantly it will not allow pressure in the system to build any higher.
When the restriction is removed the pressure falls back below the 70PSI maximum and the controller restarts the pump at the preset flow.
At the optimum calibration setting on our controllers, our pumps draw 4.5amps at dead end. If we allowed the pump to cut off at 100psi, the pump would be drawing 7 to 8amps, thus wasting energy from the battery.
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All I can say is that apart from when I first set my pump, controller and remote/one stop up and calibrated it, have never needed to do it again and that was over a year and a half ago. have had problems with airlocks etc but no calibration needed. So yeh, I can understand your request. I had tried to recalibrate over the times of my troubles but didnt seem to have any effect on anything. Mind you, I am a bit of a dum dum so hopefully someone else can enlighten us.
thats handy spruce. So im thinking, I should re calibrate and this could be more efficient on my battery and get better flow with controller not turned up so high? I must admit, i thought I,d needed the controller turned up higher than usual, but didnt consider calibration as an issue.
Mines analogue mate so dont have numbers, but I presume 43 is about half way? so seems normal.
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What I found unusual about different systems is the settings required on my old system my Cal was 39 and Flo 43, on my new system my Cal has to be at 55 or a little above as the temps have dipped a bit too ensure the pump will work along with a Flo of 23
We find it advantageous to recalibrate the controller twice a year. In winter the dead end needs to be set higher than in summer as the water is colder. The hose is also colder and doesn't have the same flexibility as it does in summer when the water is warmer.
So a correctly set controller is a must if you need to be frugal on battery demands.
Most of us with large batteries probably won't notice any difference, but the cleaners using smaller batteries in a pump box could.
Would you get a better flow? If the controller's calibration was set too low and the pump was pulsing then it would make a difference. But under normal conditions, no.
It all about saving current when you switch your flow off to the pump.
In the winter the water is colder so doesn't flow as easily through the hose as it does when its warmer. So we tend to increase our flow in winter to compenstate. Increasing the flow will put more 'strain' on the pump so will use a little more current. To add to this, a cold battery is up to 25% less efficient in winter.
This is why I 'bench' charge the leisure battery every night in winter and every second night in summer. I also have a split charge relay.
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Charging a battery after every use even 2hrs yesterday after doing a school I put it on charge, Halfords 70ah battery 15 months old and still going strong I assume as yesterday even after around 4 hours it was still charging.
yep, from what ive heard you cant go wrong smart charging them that regular. they wont take what they dont need so shouldnt go wrong really.
This battery charging is just so interesting. On Friday we had a heavy morning with both hose reels going full ball. We broke for a coffee at McDonalds at lunch time before going back in the afternoon. When I started the engine the first amp pulse into our leisure battery was 27 amps. I have never seen it up that high. But it very quickly dropped to 7 amps. Both pumps had been drawing just over 9 amps an hour so the battery was accepting less in charge than it had been discharging.
When we got back at around 16.30 I put the battery on charge. The charger was still on at 21.30 when I went out to check it. I just left it on all night. It was on float charge on Saturday morning.
Poles Apart
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I started with a Trolley system and it kept blowing hoses and getting air locks found out the pressure was to high it had settings A-G I think found out I needed it on A you are only supposed to set it at the minimum needed to get the water out at the brush end so for example if you had a 70 ft pole you would need more pressure to pump the water through.
I'm guessing that you had a Varistream. Same principal though except on a Varistream you have to up or lower your calibration setting manually.
Poles Apart
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Calibration is a complete headache for me. I had a problem the other day and had to recalibrate which brought it down to 30 odd and it wasn’t working properly then highered it to what it was originally and it magically worked when it previously didn’t ?
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The only thing that baffles me about my new controller is the battery reading is 20.3
The only thing that baffles me about my new controller is the battery reading is 20.3
That's a fault somewhere @Ian Sheppard
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This is probably why I don't drink Brown Ale ?The only thing that baffles me about my new controller is the battery reading is 20.3
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I apologise if you were trying to start up an intelligent conversation about battery voltage etc, you should by now I am not very bright ? I remember part of something you said some time ago so I know by ensuring I charge the battery as I should that a healthy battery will take some hours to charge, were as a failing battery can appear to reach a full charge a lot quicker but yet die within a few hours as I have found in the past, only going off my Halfords smart charger and checking so often on charging.
Having just bought a leisure battery and not knowing anything about battery voltage, How do I know when to charge it? The controller let me know the condition of the battery 12. 4 volts I think as it’s fully charged. I don’t have a split charge relay so it will be bench charged or charged in the back of the van. Is there a voltage rating when I should put it on charge, Or is there a simple little gadget I can just connect to the battery going from red to green to give me A visual indicator. Again sorry I know nothing about this sort of thing?
