Atlas Copco PowerMACS 4000, User Manual

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Tightening
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6.5.2.2 DT2 - Run until Dyna-Tork
TM
, method 2
Step type Id: 34
Parameters : T (Torque), TI1 (Time1), TI2 (Time2), PERC (Current percentage), DIR (Direction).
Function : Run spindle, in DIR direction, until torque is T using transducer control. When the target is
reached the current measured on the current input channel at this point is sampled and a
new current set point is calculated as
Current Set point = Measured current * PERC / 100
The current is then retained during the next TI1 + TI2 seconds using current control.
The PERC parameter makes it is possible to Dyna-Tork
TM
at a lower level than the target.
Note: To avoid overheating of the spindle it is strongly recommended to never run Dyna-
Tork
TM
to more than 40% of the maximum torque of the spindle.
Result var .: This step produces t
he step level result variables “DT T”, "DT Mean T" and "Relax A".
"DT T" is the torque measured when the torque set point is switched to DT.
"DT Mean T" is the mean torque measured during the second time interval (TI2).
"Relax A" (relaxation angle) is the angle that the bolt moves during the time interval
TI1 + TI2
Trace : Torque T is shown as a horizontal line from step start to step stop in trace when Torque vs.
Time is selected. Control parameters must be enabled in the trace form (see
View of
trace curves).