BK60C-H ASTEC [Astec America, Inc], BK60C-H Datasheet - Page 11

• Manufacturer Part Number: BK60C-H
• Description: 36 Vdc to 75 Vdc Inputs, 150 W
• Manufacturer: ASTEC [Astec America, Inc]

Technical Reference Notes (TRN)
Thermal Considerations
The power converter operates in a variety of thermal environments: however, sufficient cooling
should be provided to help ensure reliable operation of the converter. Heat-dissipating
components are thermally coupled to the case. Heat is removed by conduction, convection and
radiation to the surrounding environment. Proper cooling can be verified by measuring the case
temperature.
Heat Transfer Characteristics
Increasing airflow over the converter enhances the heat transfer via convection. Figure 13 shows
the maximum power that can be dissipated by the converter without exceeding the maximum
case temperature versus local ambient temperature (T
(400 ft/min).
Systems in which these converters are used generate airflow rates of 0.25 m/s (50 ft/min) due to
other heat dissipating components in the system. Therefore, the natural convection condition
represents airflow rates of approximately 0.25 m/s (50 ft/min). Use of Figure 13 is shown in the
following example.
Example
What is the minimum airflow required for an 033F40H operating at 48 V, an output current of 25
A, and maximum ambient temperature of 55 ºC.
Solution:
_____________________________________________________________
ASTEC POWER - Andover
Given: Vi = 48 V, Io = 25 A, T
Determine P
Determine airflow (Figure 16): v = 1.0 m/s (200 ft/min)
30
25
20
15
10
5
0
25
D
30
(Figure 16): P
Figure 13. Forced Convection Power Derating
35
40
45
D
A
50
= 13 W.
Power Derating Curve
= 55 ºC.
Ambient Temperature (ºC)
55
BK60C SERIES
60
65
70
A
) for natural convection through 2.0 m/s
75
36 Vdc to 75 Vdc Inputs, 150 W
80
85
90
95 100 105 110
Nat. Conv.
0.5 m/s (100 ft/min)
1.0 m/s (200 ft/min)
2.0 m/s (400 ft/min)
BK60C-H Series
11 of 14