E
EZHIXZH
Approved
Ericsson Internal
PRODUCT SPECIFICATION
No.
3 (3)
Prepared (also subject responsible if other)
1/1301-BMR 628 Uen
Checked
Date
3
Reference
PKD 4000E
SI
SEC/D (Julia You)
series
Safety Specification
DC/DC converters, Input 36-75 V, Output up to
20
A/50 W
2007-10-8
EN/LZT 146
375
R2B
July
2008
Rev
B
© Ericsson Power Modules AB
DC/DC converter that imposes a short circuit on the input source, this
fuse will provide the following functions:
•
•
Isolate the faulty DC/DC converter from the input power
source so as not to affect the operation of other parts of the
system.
Protect the distribution wiring from excessive current and
power loss thus preventing hazardous overheating.
General information
Ericsson Power Modules DC/DC converters and DC/DC regulators are
designed in accordance with safety standards IEC/EN/UL60950,
Safety
of Information Technology Equipment.
IEC/EN/UL60950 contains requirements to prevent injury or damage
due to the following hazards:
•
•
•
•
•
•
Electrical shock
Energy hazards
Fire
Mechanical and heat hazards
Radiation hazards
Chemical hazards
The galvanic isolation is verified in an electric strength test.
The test voltage (V
iso
) between input and output is
1500 Vdc or 2250 Vdc for 60 seconds (refer to product specification).
Leakage current is less than 1 µA at nominal input voltage.
24 V DC systems
The input voltage to the DC/DC converter is SELV (Safety
Extra Low Voltage) and the output remains SELV under normal and
abnormal operating conditions.
48 and 60 V DC systems
If the input voltage to the DC/DC converter is 75 Vdc or less, then the
output remains SELV (Safety Extra Low Voltage) under normal and
abnormal operating conditions.
Single fault testing in the input power supply circuit should be performed
with the DC/DC converter connected to demonstrate that the input
voltage does not exceed
75 Vdc.
If the input power source circuit is a DC power system, the source may
be treated as a TNV2 circuit and testing has demonstrated compliance
with SELV limits and isolation requirements equivalent to Basic
Insulation in accordance with IEC/EN/UL60950.
Non-isolated DC/DC regulators
The input voltage to the DC/DC regulator is SELV (Safety
Extra Low Voltage) and the output remains SELV under normal and
abnormal operating conditions.
On-board DC-DC converters and DC/DC regulators are defined as
component power supplies. As components they cannot fully comply
with the provisions of any Safety requirements without “Conditions of
Acceptability”. Clearance between conductors and between conductive
parts of the component power supply and conductors on the board in
the final product must meet the applicable Safety requirements. Certain
conditions of acceptability apply for component power supplies with
limited stand-off (see Mechanical Information for further information). It
is the responsibility of the installer to ensure that the final product
housing these components complies with the requirements of all
applicable Safety standards and Directives for the final product.
Component power supplies for general use should comply with the
requirements in IEC60950, EN60950 and UL60950
“Safety of
information technology equipment”.
There are other more product related standards, e.g. IEEE802.3af
“Ethernet LAN/MAN Data terminal equipment power”, and ETS300132-2
“Power supply interface at the input to telecommunications equipment;
part 2: DC”, but all of these standards are based on IEC/EN/UL60950
with regards to safety.
Ericsson Power Modules DC/DC converters and DC/DC regulators are
UL60950 recognized and certified in accordance with EN60950.
The flammability rating for all construction parts of the
products meets requirements for V-0 class material according to IEC
60695-11-10.
The products should be installed in the end-use equipment, in
accordance with the requirements of the ultimate application. Normally
the output of the DC/DC converter is considered as SELV (Safety Extra
Low Voltage) and the input source must be isolated by minimum Double
or Reinforced Insulation from the primary circuit (AC mains) in
accordance with IEC/EN/UL60950.
Isolated DC/DC converters
It is recommended that a slow blow fuse with a rating twice the
maximum input current per selected product be used at the input of
each DC/DC converter. If an input filter is used in the circuit the fuse
should be placed in front of the input filter.
In the rare event of a component problem in the input filter or in the
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