Rockwell Automation 2092-DAx Ultra1500 User Manual - Manual (Page 21)

Publication 2092-UM001D-EN-P — July 2005
Installing Your Ultra1500 1-9
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 Ultra1500 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 power
inputs, the power output (KVA) of each axis must be known. This can be
derived by calculating the Watts for each axis. If you are supplying power to
more than one motor and an Ultra1500, simply add the kW ratings together
from each calculation to get a system kW total.
Definitions:
kW = power or real power
KVA = apparent power
Transformer KVA rating = (Sum of average output power of each axis) x 2.0.
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
ratings of the drive.
A
0.38Q
1.8T 1.1 –
------------------------ = A
4.08Q
T 1.1 –
---------------- =