Set Wrap Gain - ABB PFEA 111 User Manual

Tension Electronics PFEA111/112, User Manual
Chapter 3 Commissioning

3.12.5 Set Wrap Gain

WebTension
> 5 s
Fast SetUp
Presentation-
Menu
SetObject
NominalLoad
ZeroSet
SetWrapGain
Voltage Output
Current Output
Miscellaneous
Menu
ServiceMenu
3-16
To be able to present actual web tension on the display, the ratio between web tension and
measured force on the load cell must be determined.
This ratio is a scaling factor called Wrap Gain.
The Wrap Gain depends on the web's wrap angle on the measuring roll and the orientation of the
load cells. Therefore, Wrap Gain depends on the actual installation.
This gives:
T (tension) = Wrap Gain F
From ZeroSet
SetWrapGain
To
VoltageOutput
Figure 3-10. Wrap Gain Menus
There are two ways to find out the ratio between web tension and measured force on the load
cells, by Hanging weights or by Calculation.
• With hanging weights (Menu HangWeight)
String a rope that follows the web path exactly and apply a known weight.
The applied known weight simulates the actual web tension and the electronics measures
the resulting force on the load cells caused by the applied weight.
When both web tension (T) and the corresponding measured force (F
tension electronics calculates the ratio T / F
When web tension is applied to the roll the tension electronics calculates web tension by
multiplying the measured force on the load cells with the Wrap Gain.
After the hanging weight procedure the wrap gain calculated by the tension electronics can
be found in the EnterWrapGain menu.
Weight
Figure 3-11. Setting Wrap Gain with Hanging Weights (example of installation)
(force of web tension in load cell measuring direction)
R
HangWeight
XXXXXX.X N
EnterWrapGain
XX.XX
and stores the value as Wrap Gain.
R
Load cel l
supported roll
HangWeight
[XXXXXX.X] N
EnterWrapGain
[XX.XX]
) are known the
R
All rolls must be
free turning idlers.
To keep friction
losses low, only
use the closest
Rope
rolls to define web
path.
3BSE029380R0101 Rev C