Rockwell Automation 2098-IPD-xxx Ultra5000 Intelligent Positioning Drives Installation Manual - Manual (Page 21)

Publication 2098-IN001E-EN-P — April 2002
Installing Your Ultra5000 1-7
Sizing an Enclosure
As an additional aid in sizing an enclosure, with no active method of
heat dissipation, either of the following approximate equations can be
used:
Transformer Sizing
The Ultra5000 does not require isolation transformers. However, a
transformer may be required to match the voltage requirements of the
controller to the available service. To size a transformer for the main
AC power inputs, the power output (KVA) of each axis must be
known. This can be derived by calculating the horsepower for each
axis and converting that horsepower into units of watts. If you are
supplying power to more than one motor and an Ultra5000, simply
add the kW ratings together from each calculation to get a system kW
total.
Calculating Transformer Size Based on Speed/Torque Data
Base the transformer size on the operating point within the speed/
torque curve for the drive and motor application as shown in
Figure
1.2 . The operating point for this hypothetical 230V drive/motor
combination is 23 lb-in and 3200 rpm.
Metric Standard English
Where T is temperature difference between
inside air and outside ambient (°C), Q is
heat generated in enclosure (Watts), and A
is enclosure surface area (m
2
). The exterior
surface of all six sides of an enclosure is
calculated as
Where T is temperature difference between
inside air and outside ambient (°F), Q is
heat generated in enclosure (Watts), and A
is enclosure surface area (ft²). The exterior
surface of all six sides of an enclosure is
calculated as
A = 2dw + 2dh + 2wh A = (2dw + 2dh + 2wh) / 144
Where d (depth), w (width), and h (height)
are in meters. Where d (depth), w (width), and h (height)
are in inches.
IMPORTANT
If using an autotransformer, ensure that the phase to
neutral/ground voltages do not exceed the input
voltage rating of the drive referenced in
General
Power Specifications on Page A-1 .
A
0.38Q
1.8T 1.1 –
------------------------ = A
4.08Q
T 1.1 –
---------------- =