Thanks for this Ian, I had been assuming that the Cal figure and the flow figure were on and the same. The controller AutoCal went to 49 and I then set the flow at 35 which was way too slow. Is there then a correlation between Cal and flow whereby flow should always be around 20 higher than the Cal? Is the Cal therefore the % of capacity that the pump is working at? So 35%, 49% etc
If so then at C49 my flow should be around 69 which explains why (at 35-65) it has been so slow! Would it be better to keep increasing the flow to 69 and beyond, thus increasing the gap between Cal and flow, or increase them both at the same time, so 50/70, 55/75 and so on
As ian has just said it depends on your setup, even your jets on the brush different sizes will allow more or less water to be pushed through them.
my cal as far as i can remember is set around 50-60 when cleaning windows my flow is about 23-24 using 60 meter's of Microbore and gardiners standard jets they but on all brushes.. i feel thats enough water its probably about 1.6 liters a min and flows out nicely due to the jet size i dont get any spots either.
Good question CBWC. In short Calibration does not have an impact on flow rates. But a higher flow rate will mean the calibration is likely to be higher as below.
In every system the pressure dynamics will be different. Pressure in the system is created by 1. The pump 2. Hose bore and expansion rate 3. Brush Jets
So why calibrate the controller to a pump?What we are doing is telling the control 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 control 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).
During this DE (flow stopped period) the controller periodically retests the pressure at the pump. When the restriction is removed the pressure falls back below the 70PSI maximum and the controller restarts the pump at the preset flow.
The control is designed to stop the pump well before the pump pressure switch activates when the water flow has been stopped. A pump pressure switch may activate at 110PSI give or take (based on 100 PSI pump) running the pump to these high levels can cause problems due to the inductive load
(stored energy) arcing across the PS and burning it out.
The lower the calibration setting the more sensitive the control is to changes in the system pressure and the faster the pump will be dead ended. Conversely the higher the cal setting the less sensitive the control is and the slower it DE the pump.
Flow RateCalibrating the control to your system tells the control the normal working operating PSI. Changing the flow rate increases or decreases the speed of the pump the faster the pump the greater the flow and pressure to the brush head.
How high the flow rate will vary according to the requirements of the job in hand. Ideally you are looking for the lowest flow rate possible to achieve good results. The exception is probably rinsing, a higher flow during rinsing can give a better finish particularly with hydro phobic glass.
http://springltd.co/node/137Although there is no direct correlation between Calibration and flow, The higher the flow rate the higher the calibration will be. The reason for flow affecting calibration is system pressure will be higher as the pump speed is increased.
This in turn increases the base line operating pressure of the system which may mow be 50 - 80psi. This means if the controller calibration is low the pump will be dead ended very quickly as it takes less time for the system to exceed the base operating pressure. Turning the calibration up makes the controller less sensitive to the pressure increase and slower to DE the pump.
As a general Rule I would expect most controllers to auto cal between 25 - 60 and flow rates to vary from 15 - 30 at the lower cal range and 50 to 80 at the upper end of the Cal range.
Running your pump with a cal around 45 - 60 and a flow up to 80 will draw 4 - 5amps an hour approx from a battery. Now dependent on the type of jet you are likely using 2 - 3 ltrs a minute at the higher ranges.
Compared to a system with no control that is drawing up wards of 7 - 8 amps and hour with little increase in Ltr per min.
One of the benefits of a controller is reducing strain in the system slowing the pump to reduce current draw and give full flexibility to water flow.
Other factors can effect the Flow are Pump motor efficiency, Battery condition, Air or blockages in the system and even the condition of cables between the battery - control and pump.
To answer you other question re what I have Cal set to. I work for the company who make most of the controllers as such I am not using the unit every day in a cleaning situation. My advice comes from testing the controllers and speaking to professionals doing the job day to day. The controller has developed in direct response to feed back we get.