Settings Milltronics BW500

Good day!

I have a question about the BW500 device:

What can be affected by changing parameter P014 "Speed constant"? 

In the instructions I found only one parameter P952, please confirm.

I also ask you to clarify whether changing parameter P014 can somehow affect the measurement of load (kg/m)? 

Hi AlexKuz1986,

the speed constant represents the number of pulses expected per m of belt travel. Based upon this value the belt speed and subsequently the rate are calculated. If it is not accurately programmed the rate and total given by the BW500 will never be accurate.

There is a relatively simple formula given for the value here: speed sensor pulses per revolution / pulley circumference (m).

For the RBSS P015 is 150,4; for the TASS the speed constant is 9,947; for the WS100 it is 8 / pulley circumference (m); and, for the WS300 it is 256 (or 32, 1000, 2000 ppr) / pulley circumference (m).

Hope that this helps!

Richard Deal | LevelWac

Sorry, I should also state that the device will attempt to take you through the parameters automatically once you select speed constant - either P690 as 1 (where you just enter the speed constant provided on the engineering) or 2 where you will be taken to P691 and 692 to enter the drive pulley diameter and the pulses per sensor revolution and have the BW500 calculate the speed constant.

Regards,

Richard Deal | LevelWac

Hi AlexKuz1986,

Sorry for the delay. I am not sure I follow you here...

If you decrease the design speed without doing anything to the speed constant you are only succeeding in reducing the overall speed or increasing the rate error of the application.

Do you know which speed sensor is installed on your application and the diameter of the pulley it is attached to? With this information I can see what your speed constant and P951 and P952 should be...

If you provide me the rate of the application too as well as the idler spacing I can give you an idea of what your live and dead loads should be - although these won't change...

Richard Deal | LevelWac

Hi LevelWac! Thanks for the answer. 
Attached is a photo of the speed sensor 
and shaft diameter (85 mm)

I also ask you to look at the photo with
the same problem on another conveyor.
Photo1 - BW500 readings without load
Photo2 - set the load to 8 kg
​Photo 3 - readings of BW500 with installed load kg/m
Photo4 - parameter P014
Photo5 - parameter P014 changed the speed and reduced it by 25%
Photo6 - the value of the instantaneous load kg/m has changed
question: why does the load value (kg/m) change? the load (kg/m) on the load cell does not change. How can you reduce the speed P014 so that the load (kg/m) does not change
Link to photo​
[snip]

Hi Alex,

the diameter of the pulley needs to be at the widest part (generally where it contacts with the belt), you have just provided the shaft diameter, but not the drum diameter that is contact with the belt. If you can provide me that diameter I can provide you a speed constant based on your 500 ppr.

Regarding your second post, your test weight is only applied to one side of the scale. So you should firstly make sure it is in the middle of the idler if possible, otherwise you will need to hang it once right and once left and modify the test rate accordingly.

Hi Alex,

I work out that the speed constant here should be 454,96 (based on 500 ppr and a shaft diameter of 350mm).

This doesn't explain the differences in instantaneous load you are seeing though.

Are your idlers properly aligned? Is your belt evenly loaded? What tensioner do you use on your conveyor?

Richard Deal | LevelWac