Clean It Up
UK Window Cleaning Forum => Window Cleaning Forum => Topic started by: Ben wood on June 15, 2012, 06:15:41 pm
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Hi guys
I have a shurflo pump with digi varistream, now when i turn the tap off the varistream cuts of the flow, but when i open the tap the pump takes a while to kick in so there is no flow out of the brush jets for say 8 seconds.
Is this normal or is there a way i can make a flow from the min the tap is open, It is realy ping me off.
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Calibrate the de (dead end) detection.
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How do you do that
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No Flow or no water?
If the flow takes a while to increase your problem is backpressure. Take out, Bypass, or undo your pressure switch screw with an allen key. (Huge issue when using hot water system) If there is no water and pump is not starting I would say a wiring problem.
BVC.
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All sorted, it was the presure switch so i un wired it
Thanks
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Hi Ben.
I'm glad you found the solution.
One of the reasons for a Varistream made for Williamson Pumps was to make the pressure switch redundant, and so the instructions when fitting clearly state that the pressure switch is to be bypassed.
If the pressure switch is in perfect condition on the pump then there is no reason why you should experience this delay. There are controllers out there that merely reduce the motor's speed to reduce flow, but they still rely on the pressure switch operation to cut the pump when the flow is switched off at the tap for example.
I have seen a situation though where this exact issue of the Varistream being wired through the pressure switch caused a reaction delay, which can only be put down to a poor connection at the contact points of the pressure switch, because the problem ceased when the pressure switch was bypassed as yours has.
So adjusting the pressure switch setting isn't relevant as a solution, as a Varistream doesn't work like that.
Also resetting the dead end detection point on your Varistream is also not the correct solution. You adjust the dead end detection point if you notice that the pump starts to pulse (on and off) at a slightly higher flow rate than you usually use and has nothing to do with the reaction delay.
You will however experience a reaction delay from time to time when your pump fails to kick in immediately after the tap to your pole is opened. This is due to electronic reaction time. If you couple your brush up, switch off the tap and switch on your pump controller, the pump will run for a few moments and once the pressure has built up it will cut out. Once the pump has cut out, measure the time delay the controller is programmed for to when it tries to restart the pump again. Do this for a couple of cycles and you will probably get a figure of about 4 to 5 secs.
This will be your worst delay when opening your flow to start cleaning before the pump kicks in. So sometimes you may open the tap at exactly the time the controller pulses the pump and sometimes it will be just after so you will have to wait for the next pulse. Some hose though might expand a bit under pressure before the pump cuts out. This acts as the bit of a reserve reservoir so the delay of the controller may never be noticed in this case.
Spruce