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Cassette Style
DC-DC Converters
Q Series
Edition 5/5.2000
23/25
Isolation
The electric strength test is performed as factory test in accordance with IEC/EN 60950 and UL 1950 and should not be
repeated in the field. Power-One will not honour any guarantee claims resulting from electric strength field tests.
Table 18: Isolation
Characteristic
Input
Output
Out OK
Unit
to case
to output
to case
to output
to input
to case
to output
Electric
Required according to
1.0
2.0 1
0.5
-
2.0 1
1.0
2.0 1
kVrms
strength
IEC/EN 60950
1.4
2.8 1
0.7
-
2.8 1
1.4
2.8 1
kV DC
test voltage
Actual factory test 1 s
2.1
4.2 1
2.1
0.3
4.2 1
2.1
4.2 1
AC test voltage equivalent
1.5
3.0 1
1.5
0.2
3.0 1
1.5
3.0 1
kVrms
to actual factory test
Insulation resistance at 500 V DC
>300
>100 2
>300
M
1 In accordance with IEC/EN 60950 only subassemblies are tested in factory with this voltage.
2 Tested at 300 V DC.
For creepage distances and clearances refer to:
Technical Information: Safety.
Safety of operator accessible output circuit
If the output circuit of a DC-DC converter is operator acces-
sible, it shall be an SELV circuit according to the IEC/EN
60950 related safety standards.
The following table shows some possible installation con-
figurations, compliance with which causes the output circuit
of the DC-DC converter to be an SELV circuit according to
IEC/EN 60950 up to a configured output voltage (sum of
nominal voltages if in series or +/– configuration) of 35 V.
However, it is the sole responsibility of the installer to en-
sure the compliance with the relevant and applicable safety
regulations. More information is given in:
Technical Infor-
mation: Safety.
Standards and approvals
All Q series DC-DC converters correspond to class I equip-
ment. They are UL recognized according to UL 1950, UL
recognized for Canada to CAN/CSA C22.2 No. 950-95 and
LGA approved to IEC/EN 60950 standards.
The units have been evaluated for:
Building in,
Basic insulation between input and case and double or
reinforced insulation between input and output, based on
their maximum rated input voltage,
Basic insulation between Out OK and case and double or
reinforced insulation between Out OK and input and be-
tween Out OK and output, based on their maximum rated
input voltage,
Operational insulation between output(s) and case
Operational insulation between the outputs
Use in a pollution degree 2 environment,
Connecting the input to a circuit which is subject to a
maximum transient rating of 1500 V.
The DC-DC converters are subject to manufacturing sur-
veillance in accordance with the above mentioned UL,
CSA, EN and with ISO 9001 standards.
AC-DC
front
end
DC-DC
con-
verter
Mains
Fuse
Battery
Earth
connection
Suppressor
diode
SELV
Earth
connection
+
–
~
10026
Fuse
Earth
connection
Fig. 30
Schematic safety concept
Use fuse, suppressor diode and earth connections as per
table:
Safety concept leading to an SELV output circuit.
Use fuse(s) also if required by the application. See:
Instal-
lation Instructions.