3.2 Derating
¡
Environment to use it and Installation environment
When using it,it is necessary to radiate heat by the heat of the pow-
er supply.
Table 3.1 - 3.9 shows the relation between the upper limit tempera-
ture (Point A and Point B) and load factors.
Please consider the ventilation so that the convection which is
enough for the whole power supply is provided.
And temperature of Point A and Point B please become lower than
upper limit temperature.
The expectancy life in the upper bound temperature (Point A and
Point B) is three years or more.
Please refer to External View for the position of Point A and Point B.
In case of with Chassis and Cover, please contact our sales offi ce
for getting more information.
Remarks:
*
Please be careful of electric shock or earth leakage in case of
temperature measurement, because Point A and Point B is live
potential.
*
Please refer to 3.4 if you want to extend the longevity of the ex-
pectancy life.
Table 3.1 Temperatures of Point A, Point B LFA10F-
O
Mounting
Method
Cooling
Method
Load factor
Max temperature
Point A[
C
]
Point B[
C
]
A
Convection
20%
<
Io
[
100%
70
84
Io
[
20%
75
79
B
Convection
20%
<
Io
[
100%
70
81
Io
[
20%
73
77
C
Convection
20%
<
Io
[
100%
76
80
Io
[
20%
76
77
D
Convection
20%
<
Io
[
100%
70
78
Io
[
20%
75
77
E
Convection
20%
<
Io
[
100%
73
84
Io
[
20%
76
79
F
Convection
20%
<
Io
[
100%
74
80
Io
[
20%
76
78
A,B,C,D,E,F Forced air
70%
<
Io
[
100%
75
75
Io
[
70%
75
75
2.2 Parallel Operation
¡
Parallel operation is not possible.
¡
Redundancy operation is available by wiring as shown below.
¡
Even a slight difference in output voltage can affect the balance
between the values of I
1
and I
2
.
Please make sure that the value of I
3
does not exceed the rated
current of a power supply.
I
3
[
the rated current value
3.1 Installation method
¡
This power supply is manufactured by SMD technology.
The stress to P.C.B like twisting or bending causes the defect of
the unit,so handle the unit with care.
¡
In case of metal chassis, keep the distance between d
1
& d
2
for to
insulate between lead of component and metal chassis, use the
spacer of 8mm or more between d
1
. If it is less than d
1
& d
2
, insert
the insulation sheet between power supply and metal chassis.
3
Assembling and
Installation Method
¡
There is a possibility that it is not possible to cool enough when
the power supply is used by the sealing up space as showing in
Figure 3.2.
Please use it after confi rming the temperature of point A and point
B of Instruction Manual 3.2.
AC-DC Power Supplies Open Frame/ Enclosed Type
Instruction Manual
LFA-24
LFA
I
2
I
1
I
3
-
+
+
-
Load
Power
Supply
Power
Supply
Fig.2.4 Example of redundancy operation
Fig.3.1 Installation method
= 8mm min
= 4mm min
CN1
CN1
d
2
d
1
d
2
d
2
d
2
d
2
d
2
Power supply
Case
Fig.3.2 Installation example
me̲lfa1.indd LFA-24
me lfa1 indd LFA-24
2015/06/15 15:22:54
2015/06/15 15:22:54
