Triton Go Product Manual |
Product Description
INGENIA | 05/29/2017
18
4.4.2 Current ratings
Power losses cause the drive to increase its temperature according to:
As power losses have a positive correlation with the motor RMS current, when the ambient temperature rises,
the output current must be limited to avoid an excessive drive temperature (T
P
< 110 ºC). The threshold
temperature where the current derating should start mainly depends on the DC bus voltage. Then, although a
1.2 ºC/W heatsink is required to reach the nominal current at the nominal DC bus voltage (48 V), the same
nominal current can be reached with a less restrictive heatsink when DC bus voltage is lower. Also, other
environmental parameters can relax the required heatsink thermal resistance to reach nominal current,
typically:
•
Air flow around the drive.
•
Position (vertical allows natural convection).
Parameter
Val
ue
Unit
s
Notes
Maximum power stage
temperature
110
ºC
Measured on the PCB (not the heatsink) and accessible
via register.
Thermal resistance
from
power stage to heatsink
3.6
ºC/
W
Does not consider the thermal resistance of the heatsink,
but assumes
the coldplate is a thermal conductor, not the thermal
dissipator.
Thermal resistance
from
power stage to air
13
ºC/
W
Considering the coldplate acting as the thermal dissipator
(no heatsink
attached).
