Feature descriptions, Thermal considerations – GE Industrial Solutions EVW010A0B Series (Eighth-Brick) User Manual
Page 8
Data Sheet
September 4, 2013
EVW010A0B Series Power Modules
36 – 75Vdc Input; 12.0Vdc Output; 10A Output Current
LINEAGE
POWER
8
Feature Descriptions
(continued)
back into its specified range. The average output 
current during hiccup is 10% I
O, max
.
Output Voltage Programming
Trimming allows the output voltage set point to be 
increased or decreased, this is accomplished by 
connecting an external resistor between the TRIM pin 
and either the V
O
(+) pin or the V
O
(-) pin.
V
O
(+)
V
O
TRIM
V
O
(-)
R
trim-down
LOAD
V
IN
(+)
ON/OFF
V
IN
(-)
R
trim-up
Figure 12. Circuit Configuration to Trim Output 
Voltage. 
Connecting an external resistor (R
trim-down
) between
the TRIM pin and the Vo(-) (or Sense(-)) pin 
decreases the output voltage set point. To maintain 
set point accuracy, the trim resistor tolerance should 
be ±1.0%. 
The following equation determines the required 
external resistor value to obtain a percentage output 
voltage change of ∆% 
22
.
10
%
511
down
trim
R
Where
100
%
,
,
set
o
desired
set
o
V
V
V
For example, to trim-down the output voltage of the 
module by 8% to 11.04V, Rtrim-down is calculated as 
follows: 
8
%
22
.
10
8
511
down
trim
R
655
.
53
down
trim
R
Connecting an external resistor (R
trim-up
) between the
TRIM pin and the V
O
(+) (or Sense (+)) pin increases
the output voltage set point. The following equations 
determine the required external resistor value to 
obtain a percentage output voltage change of ∆%: 
22
.
10
%
511
%
225
.
1
%)
100
(
11
.
5
, set
o
up
trim
V
R
Where
100
%
,
,
set
o
set
o
desired
V
V
V
For example, to trim-up the output voltage of the 
module by 5% to 12.6V, R
trim-up
is calculated is as
follows:
5
%
22
.
10
5
511
5
225
.
1
)
5
100
(
0
.
12
11
.
5
up
trim
R
8
.
938
up
trim
R
The voltage between the Vo(+) and Vo(–) terminals 
must not exceed the minimum output overvoltage 
protection value shown in the Feature Specifications 
table. This limit includes any increase in voltage due 
to remote-sense compensation and output voltage 
set-point adjustment trim. 
Although the output voltage can be increased by both 
the remote sense and by the trim, the maximum 
increase for the output voltage is not the sum of both. 
The maximum increase is the larger of either the 
remote sense or the trim. The amount of power 
delivered by the module is defined as the voltage at 
the output terminals multiplied by the output current. 
When using remote sense and trim, the output 
voltage of the module can be increased, which at the 
same output current would increase the power output 
of the module. Care should be taken to ensure that 
the maximum output power of the module remains at 
or below the maximum rated power (Maximum rated 
power = V
O,set
x I
O,max
).
Thermal Considerations
The power modules operate in a variety of thermal 
environments; however, sufficient cooling should be 
provided to help ensure reliable operation. 
Considerations include ambient temperature, airflow, 
module power dissipation, and the need for increased 
reliability. A reduction in the operating temperature of 
the module will result in an increase in reliability. The 
thermal data presented here is based on physical 
measurements taken in a wind tunnel. 
The thermal reference point, T
ref
used in the
specifications for open frame modules is shown in 
Figure 13. For reliable operation this temperature 
should not exceed 122
o
C.
Figure 13. T
ref
Temperature Measurement
Location for open Frame Module. 
The thermal reference point, T
ref
used in the
specifications for modules with heat plates (–H) is 
shown in Figure 14. For reliable operation this 
temperature should not exceed 114
o
C.
AIRFLOW