CME-7
CME
・
All specifications are subject to change without notice.
CME240P
For CME240P-24, the peak output current should satisfy the
conditions below:
(1) Should not exceed the rated peak current in the specifications.
(2) Duty cycle of the peak output current should be ≤ 35%(at
input voltage < 95V : ≤ 20%), and operating time of peak
output current is less than 10 seconds. If the power supply
is oper-ated under convection cooling, and ambient ex-
ceeds 45°C, the following operating period for peak current
is recommended.
Ambient Temperature (°C)
Peak current operating time
-10 -+45°C
within 10 seconds
+45°C onwards
within 5 seconds
(3) The relation between peak output current with average out-
put current is defined as below:
T
Ip
Im
0A
Ip : Peak output current (A)
Im : Minimum output current (A)
D : Duty cycle,
τ
/T
τ
: Peak output current operating time
(sec)
T : Period
(sec)
Io : Maximum allowable average output current of specifica-
tions (Io should be average load after derating at various
mounting and am-bient temperature) (A)
Formula:
At input voltage < 95V
Io
2
≥
Ι
p
2
D+Im
2
(1-D) (Duty ≤ 20%)
At input voltage ≥ 95V
1.5 Io
2
≥
Ι
p
2
D+Im
2
(1-D) (Duty ≤ 35%)
Example 1 : For CME240P-24 at Ta =60°C, Mounting A, Input
Voltage =100V, Max Io =6A (after 60% Derating)
(A): In case of Im =0, Ip =20A,
D ≤ 13.5%
(B): In case of Im =4A, Ip =20A,
D ≤ 9.9%
Example 2 : Following table illustrate some peak load operation
examples for CME240P-24 at input voltage 100V.
Please note that the actual Io in peak load opera-tion is low.
Max allowable average
load after derating by
vari-ous Mounting and Ta :
Examples of peak load derating,
calculated by
above formula
Actual Io
Average
Load(%)
Io(A)
Ip(A)max
D max
Im(A)
Io(A)
100
10
20
35.0%
3.92
9.55
90
9
20
30.4%
0
6.08
80
8
20
24.0%
0
4.80
70
7
20
18.4%
0
3.68
60
6
20
13.5%
0
2.70
50
5
20
9.4%
0
1.88
40
4
20
6.0%
0
1.20
30
3
20
3.4%
0
0.68
20
2
20
1.5%
0
0.30
10
1
20
0.4%
0
0.08
(4) Peak output current operation (Maximum 10 seconds, Duty
: ≤ 0.2 at input voltage < 95V, ≤ 0.35 at input voltage ≥ 95V)
is possible after establish of output voltage. Please avoid
peak current operation during startup.
Isolation Test
Isolation resistance between output and FG ( chassis ) shall
be more than 100MΩ at 500VDC. For safety operation, voltage
setting of DC isolation tester must be done before the test. En-
sure that it is fully discharged after the test
Output - FG (chassis)
500VDC 100MΩ or more
Withstand Voltage
This model is designed to withstand 4.0kVAC between input and
output, 2.0kVAC between in-put and FG (chassis), and 500VAC
between output and FG (chassis), each for 1 minute. When test-
ing withstand voltage, set current limit of withstand voltage test
equipment at 20mA (Output-FG (chassis) : 100mA ). The applied
voltage must be gradually increased from zero to testing value
and then gradually decreased for shut down. When timer is
used, the power sup-ply may be damaged by high impulse
voltage at timer switch on and off. Connect input and output
as follows.
Input - Output (dotted line) 4kVAC 1min. (20mA)
Input - FG (chassis)(solid line) 2kVAC 1min. (20mA)
Output - FG (chassis) 500VAC 1min. (100mA)
+
_
AC(N)
AC(L)
FG
Isolation Tester
+
_
AC(N)
AC(L)
FG
Withstand
Voltage tester
+
_
AC(N)
AC(L)
FG
Withstand
Voltage tester
