Hypertherm THC ArcGlide - Manual (Page 122)

122 ArcGlide THC Instruction Manual 806450
2 – Installation
Voltage: This gain is used when the THC operates with a closed-loop arc voltage control. Adjust this value after you find
the appropriate value for Speed Gain.
If this value is set too high, the lifter position during closed-loop arc voltage control will become unstable and
prone to oscillation. If this value is too low, the arc voltage control can become slow and inaccurate. Test
voltage gain by repeatedly performing a test cut under closed-loop arc voltage control and verify that the
THC quickly and accurately reaches the set arc voltage.
To optimize this gain, raise this value until there is a very slight oscillation during a cut and then reduce the
setting by 1 or 2.
Range: 1 to 10; Setting: 5
Speeds
Maximum: Sets the maximum linear speed that the THC can achieve. This value depends on the lifter motor speed at
45 VDC, the screw pitch, the weight of the lifter load, and the desired speed of operation.
This value is used as the 100% speed value when scaling the control equations. It is important that this value
is set correctly because it affects the scaling of all the other control loops.
Set this parameter during installation, before optimizing Speed Gain.
Set this value to a speed that can be achieved easily. Use a conservative setting and assume a low, incoming
AC line voltage. If this speed is set too high, the maximum available motor drive voltage will be insufficient to
drive the motor to the desired maximum speed. This will make the top of the linear control range unavailable
and result in sub-optimal operation.
If the Maximum Speed is set too high, it may be difficult for the THC to operate precisely at slow speeds
when trying to control the arc voltage or to move to an accurate IHS distance. If this speed is set too low, the
linear control range will only cover the low portion of the available mechanics range and the result may not be
optimal.
For the Hypertherm 239 mm (9.40 inch) lifter, this value is 15240 mm/min (600 in/min). At the low input line
voltage limit, the motor drive is capable of supplying about 45 VDC. The motor used in the Hypertherm
239 mm (9.40 inch) lifter will produce full-rated torque at about 3,300 r/min at this voltage. The Hypertherm
239 mm (9.40 inch) lifter has a 5-mm pitch ball-screw which requires 25.4 in/mm / 5 mm = 5.08 revolutions
to travel one linear inch. This results in a value of 3,300 r/min / 5.08 revolutions/inch = 650 linear in/min of
travel speed. This value was rounded down to the nearest even hundreds to guarantee a 100% value under
all conditions.
Setting: 15,240 mm/min (600 in/min)
Fast: This speed governs all automatic rapid moves such as the End-of-Cut-Retract or the Initial Approach to the
workpiece.
Set this parameter to the value of Maximum Speed. However, you can set it lower if there is a heavy load on
the lifter. With the Hypertherm 239 mm (9.40-inch) lifter, this value is set to 15,240 mm/min (600 in/min).
Setting: 15,240 mm/min (600 in/min)